Share:

Tuesday, November 17, 2020

Improving Your NightScapes Through Tracking

November Milky Way "erupting" over Factory Butte, in the Utah Badlands. Although the core of the MW is gone until Spring, there is a lot of MW still left to shoot!


Improving Your NightScapes Through Tracking

Photographing astro-landscapes is both exciting and challenging because of the extremes this type of night photography presents to the photographer. For over a decade, 30-seconds, at f/2.8 and ISO 6400 has been the "gold standard" in nightscape style photography:



Enlarged segment of a high ISO image
The NightScape Exposure Standard: Although these exposure settings may not be optimum, they will almost always produce acceptable starry night sky during the darkest period of the night. Many photographers start with these settings to confirm their composition, then continue their in-the-field tweaking processing to improve quality. Those improvements can include exposure stacking, panorama exposures and star tracking.

Reducing ISO speeds: High ISO speeds can produce noisy, grainy and pixelated images, where the noise patterns are almost as large as the smaller stars! High ISO's reduce dynamic range and lower image resolution. Although modern DSLR and mirrorless cameras have sensors that can easily handle high ISO speeds and produce acceptable results, lowering the ISO speed will always produce better images. The two ways to reduce high ISO speeds are to either lengthen your exposure time or increase your aperture size, such as going from f/2.8 to f/2.0—both of which can cause other problems, which must then be addressed.

Same stars, with and without coma aberrations
Changing the aperture
:
f/2.8 is often the fastest (largest aperture size or smallest number) on most high-quality lenses. Increasing the aperture size is usually not an option, unless you purchase a much more expense lens that is highly corrected at f/2.0, f/1.8 or f/1.4. Even these very expense lenses can suffer from some lens aberrations and light fall off (vignetting) near the edges of the image. Stopping down to a smaller aperture will eliminate most of these "wide open" aperture problems, but that requires either an increase in ISO speed or exposure time.

Click to enlarge and compare star trailing
Changing the exposure time
:
When using a wide angle lens, 30 seconds is an acceptable exposure time for small to medium size prints or images displayed on social media. At these smaller sizes, most people will not notice that the stars are slightly blurred or trailing due to the rotation of the earth during the exposure. When printing to larger sizes, most wide angle (14mm to 24mm) images will benefit greatly from a shorter exposure, such as 20 to 13 second exposures. 35mm to 50mm lenses will do better at 10 to 6 second exposures. These changes will require wider apertures or higher ISO speeds.

And, so the "dance" continues! Changing one of the three effects the other two. Exposure stacking will solve some of these problems. Tracking will solve all of these issues, as I will explain...

Exposure Stacking is referred to by some as the "poor man's solution to tracking" as it costs little to nothing (zero to about $40 for the software app), compared to a star tracker. I find the Mac app, Starry Landscape Stacker, to give me the best results (see my tutorial here). With stacking, you use shorter exposures and higher ISO speeds to make up for shorter exposure times, in order to obtain proper histogram levels. In practice, you take about a dozen exposures as quickly as the images will write to your memory card. Back home, those images are "stacked" by the software to significantly reduce the noise between the stars. This is because every exposure has a different noise pattern. The patterns cancel each other out (smooth) via what is called "median filtration". The software (especially SLS) aligns all the stars (which move with each exposure), masks out the foreground (which does not move), and then brings both the sky and the foreground back into the final stacked image! The previous image (8 seconds @ ISO 10,000) was a 12 exposure stack. Here's another example of stacking's magic, using only 8 exposure stacks:

Each image enlarged to 200% to show detail. Click to enlarge further.


Why is Tracking is Better Than Stacking? With stacking you control only one of the exposure variables: the exposure time. You are allowed to reduce the exposure time by increasing the ISO, which noise is partially eliminated by the stacking of additional images. While stacking reduces high ISO noise, it does not recover the loss of dynamic range and sharpness due to the higher ISO speeds.

Tracking allows you to control all the exposure variables. Instead of reducing the exposure times as you do with stacking, tracking allows to increase the exposure time as long as you want, enabling you to lower your ISO speeds or stop down to better quality apertures, or both.

Trackers are not that expensive anymore. Many of the ones for astro-landscape photography are under $500. The one I recommend is typically under $300. Many photographers are purchasing trackers instead of upgrading to more expensive lenses and cameras, because the end results are better!

New tracker designs are smaller, lighter, more portable and less intimidating to set up. Some use a laser pointer for quick alignment, rather than a polar scope — which is only necessary for use with telephoto lenses (or for use in the Southern Hemisphere).

My basic MSM 2-in-1 tracker is about one-half the size and weight (1.01 lb / 450 g) as the basic Sky-Watcher Star Adventure tracker (2.2 lb / 1.0 kg), with its built in polar scope.

Note how my Move Shoot Move 2-in-1 tracker/rotator increases the number of smaller visible stars in this 30-second exposure track, which allowed an ISO drop from 8000 to 4000. Even more noticeable is how much star movement is still in the 15-second image, which is even more apparent in the 200% enlargement below it:



Increasing the tracked exposure time from 30 seconds to 120 seconds (2 minutes) allowed me to reduce my ISO from 4000 to 1000, for even less noise and more definition:




Here's my personal set-up, using the MSM 2-in1 Tracker/Rotator (see my review). I used my own MeFoto ballhead, but MSM's basic "Starter Kit" comes with a similar ballhead (actually better quality than my MeFoto Q1) and a laser Star Pointer for $310.00 (current Holiday Sale price is $239.98). Although you may already have a ballhead lying around like I did, I strongly recommend going with the "Starter Kit" option because these orders are shipped from a U.S. warehouse, and only take about 4 days to get to most continental U.S. locations. Other kit options ship directly from the factory in China and my first order took over two weeks to arrive to my Utah address.

Approaching deep space astro photography: The core of the Milky Way with the Dark Horse Nebula and the Rho Ophiuchi cloud complex in the top right. Taken with a 50mm lens. Tracked on a MSM 2-in-1.

The compact and light weight Move Shoot Move 2-in-1 Tracker/Rotator is designed for portable astro-landscape photography. It is perfect for backpacking! It's laser pointer allows to quick and easy alignment when using wide angle to 50mm lenses for nightscape photography. It can also be used for deep space photography; however, alignment accuracy is improved if the laser pointer is replaced with the Polar Scope, when using telephoto lenses like the 70mm to 200mm. Longer telephoto lenses may be too heavy for the MSM's 6.6 pound (3 kg) load capacity. If you need a tracker that can carry heavier loads and has more available counter balance accessories, I'd recommend the Sky-Watcher Star Adventurer, with its 11 pound payload capacity—however, be prepared for a more intimidating set up (my first experience took me over half an hour).

The MSM 2-in-1 Tracker/Rotator use a green laser pointer (left) for fast and simple alignment with the North Star. It is quite accurate for lenses up to 50mm. Telephoto lenses will benefit from the increased alignment accuracy of a polar scope, but alignment is a little more complicated to perform, usually taking a couple of minutes (the laser pointer detaches from the tracker and the scope attaches via a nylon thumbscrew). The polar scope is also necessary for those living in the Southern Hemisphere where Polaris is not visible.


My STEP-by-STEP procedure for taking tracked astro-landscape images with the MSM tracker:

  1. Take a few quick "NightScape Standard Exposures" to find the right position for your best composition with the foreground and sky. Do this without the tracker. I like to use two tripods—one for these quick set ups where I explore my composition, and another tripod that I can mount my tracker onto (one tripod for both is fine—it just takes a little more time for the setup).
  2. Once your best composition is found, move your other tripod (with the tracker) into the same position—replacing the tripod that has your camera on it (leave the camera on the tripod for now).
  3. Release the ballhead below the tracker and aim your laser pointer at Polaris (the North Star). Once the laser beam is on target, tighten your ballhead. (By the way, that pitch angle will be the same as your current latitude.) For best results, try to keep the tracker's "roll" as level as possible while pointing the laser up to Polaris.
  4. Your tracker is now aligned with the North Star! With practice, you can do this step in about 30 seconds. The MSM tracker with a polar scope, instead of a laser pointer, can take about 3 minutes for alignment. The first time I used the scope on a Sky-Watcher Star Adventurer, it took me over half an hour. One of my friends was so intimidated by his, he gave up (and he's a commercial airline pilot). He has never used his tracker since!
  5. The tracker should already have another ballhead (with a quick release) mounted to the rotator. Mount your camera's L-bracket to that quick release. The MSM's basic "Starter Kit" comes with a similar ballhead, if you don't already have one.
  6. Loosen the controls on this second ballhead and aim your camera to your predetermined composition.
  7. Tighten your ballhead controls and take a quick NightScape Standard Exposure. Make ballhead adjustments and repeat until you have duplicated your original composition.
  8. Before you take you first tracked exposure, you'll want to take an exposure for the foreground (with the tracker still off). Since the foreground does not move, you can make your exposure as long as you want (with a lower ISO). Do not turn on your tracker until you are satisfied with your foreground; however, don't take too long or your Milky Way may move out of position. Remember, the stars are rotating at 15 degrees per hour!
  9. You can now turn on your tracker and it will begin to rotate you camera in sync with the earth's rotation so that the stars stay perfectly still!
  10. Adjust your camera's exposure for optimum quality. For instance, if you decide to reduce your ISO from 6400 to 1600 (two stops), and your original exposure was 30 seconds, you'll now need to expose for 120 seconds. If your original aperture setting was f/2.8 and you wish to stop down to f/4.0, you'll need to go another 120 seconds, for a total of 240 seconds (4 minutes).
  11. Take your exposure! You are done, except for post processing. Total time for steps #3 thru #10 (not counting exposure time for the foreground and sky) will probably be less than three minutes. You can now shut off your tracker, so it doesn't run down the battery—which can typically run for about 5 hours of tracking.
  12. Combining the non-tracked foreground and the tracked exposures in post: When you review your last exposure, you'll notice that the foreground has moved (rotated) and blurred, especially where it meets with the sky. That's because the tracker was tracking and rotating for the sky. It's also why you should alway photograph the foreground first, before turning on your tracker! In post, you will take your sharp foreground exposure (#8) and layer it over your tracked exposure for the sky. Note: you sometimes have to slightly enlarge the foreground to cover up the blurred foreground portion on the tracked exposure. This post processing procedure is usually done in Photoshop layers. Kamil Pekala has a great YouTube tutorial for this. Another tutorial from Milky Way Mike shows how to combine a foreground with stacked image —but, the procedures are similar to combining with a tracked image. Mike's Photoshop techniques are just slightly different than Kamil's (you decide which works best for you).
Enjoy!

on the MSM 2-in-1 Tracker/Rotator thru Cyber Monday - November 30, 2020
Get an extra 11% off at checkout when you use the code "ROYCE" (instead of "BLK")




Thursday, October 8, 2020

Focusing Aids for Astrophotography


 

A review of focus magnification aids, including two Bahtinov (mask) filter products to achieve precise infinity focus for astrophotography or nightscapes.

Obtaining a sharp infinity focus is the keystone to good astro-landscape photography. If your stars are not in focus, your shot is ruined, no matter how beautiful and well planned! I cannot tell you how many times in my early nightscape adventures that I've come back from an amazing night photography shoot only to be disappointed when I enlarged my photos on the computer screen—discovering that the stars were slightly out of focus, and that I'd never be able to make a decent size print out of my efforts.


What do out-of-focus stars look light? These two beautiful photos were taken last month by R. Craig Lefebvre in Arches National Park (left) and Dead Horse Point (right), Utah. Because the Arches image was taken with a 15mm lens, the four stars shown below Jupiter, in the Sagittarius constellation, should be about 40% smaller than the same stars shot with the 24mm lens, yet they are actually larger. And, the reason they are bigger is because they are slightly out of focus. Unfortunately, it is almost impossible to see this problem until the images are projected to 100% on a computer monitor—or by using some of the advanced techniques below. Note: This image is only very slightly out of focus. It still can be used for social media and possibly for prints up to 16x20 inches. Out of focus stars that are twice this large (even blurrier "circles of confusion") are often not detected until it is too late. In these cases, the image is worthless for any practical use.

Start with You Camera's Live View: Miss-focus still happens to me occasionally, and I continue to see and hear about this disappointment and frustration from my fellow nightscapers, especially those who are just starting out. On page 53 of my Milky Way NightScapes eBook I use three paragraphs on how to manually focus and find your true infinity with the camera's Live View function. I then end with, "Once you’ve found your lens’ true infinity, mark it for future reference, or tape down the focus with a piece of gaffer’s tape. You’ll have one less thing to worry about in the dark."

Temperature Affects Focus: That advice works most of the time, but I've found that you can't always rely on it because the tape can loosen or the focus mark become meaningless due temperature changes. Changes in temperature can cause considerable focus shifts in your lens, so it is best to redo your focus each time you go out shooting at night. And, if temperatures are considerably different than the last time you were shooting, wait several minutes for your lens to adjust to the new outside temperature.

Zoom lenses often have a different infinity focus for each focal length, so no single infinity focus setting will give you accurate results throughout the zoom range of the lens.

Additional magnification to your Live View image: As we get older, it becomes much harder to see if a star is sharply focused on a 3-inch LCD camera monitor, even when the image has been magnified to 10X. For this reason, I carry an inexpensive pair of +3.0 diopter (power) reading glasses from my local drug store. This, or a Hoodman Loupe (with the Hoodman Cinema Strap) allows for hands-free, enlarged views of your little camera monitor.

Aaron King of Photog Adventures continues to promote his favorite focusing aid: The $5 Carson Lumiloupe 10X magnifier (shown in the above middle photo). Here's his 13-minute video tutorial. I've used this method for years, and I highly recommend it!

The Bahtinov mask focusing aid
:
The Bahtinov mask is a device used to accurately focus small astronomical telescopes. This distinctive pattern was invented by Russian amateur astrophotographer, Pavel Bahtinov, in 2005. The telescope is pointed at a bright star, and a mask is placed in front of the telescope's objective. The mask's three separate grids are positioned in such a way that they produce three angled diffraction spikes at the focal plane. As the telescope focus is changed, the central spike appears to move from one side of the star to the other. Optimal focus is achieved when the middle spike is centered between the other two spikes. If you like DIY projects, you can even make your own Bahtinov mask.

Bahtinov mask limitations and new product solutions: The problem with most Bahtinov masks is that they work well for small telescopes and medium to long telephoto lenses on cameras, but their use with wide angle lenses that are often used in astro-landscape photography is not as decisive.

Reviewing the SharpStar2 and the Focus on Stars filters


Improvements on the Bahtinov mask design: These two commercially available Bahtinov mask "filters" attempt to provide a more accurate and easier-to-use focusing tool for nightscape photographers. Unlike the typical Bahtinov grid or mask, these are more like true photographic filters. In the case of the SharpStar2 filter, the Bahtinov mask pattern is finely etched by laser into the clear plastic filter. The Focus on Stars filter goes even further with multiple Bahtinov mask patterns contained in a film that is sandwiched between tempered glass sheets.

Is a star focusing filter really necessary? Some may think there is no need for gadgets like this to aid photographers in getting a sharp focus on their stars, considering the available focusing tools I've already mentioned. I admit, that I was one of these people (I don't need more stuff cluttering my camera bag). However, as I've helped hundreds of students in my nightscape workshops over the years and seen them struggle to get a correct focus on the stars, even with these other tools, I'm beginning to think there is a need for a better focusing tool, and one or both filters of these might be it—especially as we get older and we struggle reading the small print (the stars on your LCD screen are even smaller, even at 10X!

Consider this: Many professional photographers resisted auto focus when it first appeared on pro SLR cameras back in the 80's—now, few of us would think of being without it! When articulating LCD camera screens first appeared a few years ago on low-end digital cameras, many scoffed at these as this gimmick. Now, they are fast becoming a "necessary"' feature in professional cameras.

PRODUCT PREVIEWS...

SharpStar2 by Lonely Speck



SharpStar is a simple tool created by Lonely Speck to help astrophotographers achieve critical focus on the stars with their camera lens and filter holder. SharpStar claims to help astrophotographers achieve perfect focus on the stars, every time.

SharpStar uses the properties of optical diffraction to create a set of three fine spike lines around a bright star. These diffraction spikes will shift position as you focus your camera. Adjusting focus so the central diffraction spike sits evenly between the other two diffraction spikes will ensure perfect focus. Once you’ve verified the focus pattern on your test shot, you can simply remove the SharpStar and shoot like normal — knowing that you have perfect focus. The diffraction spike pattern that SharpStar creates is a precise visual reference of focus success. If the central spike is off to the left, focus is too far, if it’s off to the right, focus is too near. If it’s in the center, it’s just right. Here's a 3-minute video tutorial.

Lonely Speck’s SharpStar2 is made of precision laser etched optical plastic and comes in a square filter shape, made to fit into the most popular square filter systems. SharpStar2 requires a square filter holder and the appropriately-sized system adapter ring to fit your lens (both items sold separately). The SharpStar2 works with the Lee, Cokin, Formatt-Hitech and other similar filter holders that come in 85mm, 100mm and 150mm sizes. If you don’t already have a filter system, Lonely Speck personally recommends the Formatt Hitech system because of its price and its modular design that works well with wide angle lenses. October 9 update from Lonely Speck: "The SharpStar2 is made in the USA. We offer a 100% satisfaction guarantee (refund or replacement if the customer isn't satisfied for any reason). All they need to do is email us." ~ Ian and Diana

PRICING (filter only - filter holder not included):
  • 85mm $64.00
  • 100mm $69.00
  • 150mm $94.00
Filter Pouches are optional (soft-lined semi-rigid pouch with magnetic closure)
 ~ 85mm $12.00 • 100mm $14.00 • 150mm $20.00 ~






The Focus On Stars high precision device fits into standard size square filter holders available on the market. At first glance, it looks like a filter.

In fact, it has a grid structure based on the Bahtinov mask known in astronomy, but it is much more complex. A multitude of Bahtinov masks in a special mosaic layout ensures that all three diffraction spikes are obtained quickly and easily with a maximum of two small movements (horizontal rotation, vertical slide). You only need to place it in front of the lens to fine-tune the focus, and you can remove it before the final exposure. According to the rules of diffraction, 3 pairs of bright spots appear on the LCD live image around the brighter stars.

Focus On Stars developer, Gabor Takacs, claims that his filter works better with the wide angle lenses most commonly used in astro landscape photography: "During my research, I found a promising device that the manufacturer recommended also for lenses with shorter focal length. It is a plastic sheet in which the grid lines of the Bahtinov mask known from astronomy were densely etched with laser. I have tested it. Using wide-angle lenses common in astro landscape photography, I have found that this device gives me a diffraction pattern that is too faint and too small to ensure a sharp focus. ...After more than a year of research and development, I develop a device that works well even with ultra-wide-angle lenses."

The Focus On Stars diffraction pattern has some similarities to the typical Bahtinov mask, but is also has some unique differences that help the user determine focus with more precision. When focusing, the center spot around the targeted star moves between the lateral spots. When the center spot is just equidistant from the lateral ones, i.e., the resulting pattern is symmetrical, the focus adjustment is perfect. The position of the intermediate spots also shows the direction of the required correction: If the spot is shifted to the left, the focus is in front of the target, if it is shifted to the right, it is behind the target. October 12 update: "Focus On Stars is made in Hungary (EU) and we also offer a 100% satisfaction guarantee (refund or replacement if the customer is not satisfied for any reason)." ~ Gabor Takacs.

PRICING (filter only - filter holder not included):
  • 100mm $113.00
  • 150mm $154.00
Each filter comes with a protective, hand-sewn pouch with velcro closure :



My OUT OF THE BOX Experience

SharpStar2

I ordered the 100mm SharpStar2 for $69.00, with economy shipping from California (U.S.A.) to Utah (U.S.A.) for a cost of $3. I received a notification the next day that the product was out of stock. Two days later, the product was available and I received another notification that it was shipping. The package arrived three days later, and included a filter pouch (a $14 value) that I didn't order. When I questioned (via email) the inclusion of the pouch I didn't order, they said it was free because my order had been delayed due to stocking problems (nice gesture!). Total cost for filter with shipping to the U.S.A. was $72. However, if I lived in Australia, my USPS Priority Mail Express International shipping cost would be $82.75, for a total cost of $151.75.

All-in-all, the products were just as described, and nicely packaged. The filter was enclosed in a clear plastic envelope (blue product description printed on the outside), which could be used a storage pouch for a while, but the real filter pouch (made of suede leatherette material), with its magnetic enclosure, was much nicer and more substantial. The filter seems to be finely etched with the Bahtinov mask pattern into a sheet of clear plastic.



Focus On Stars

I ordered the 100mm Focus On Stars for $113.00, with DHL Express shipping from Hungary to Utah (U.S.A.) for a cost of $32. The FOS filter comes with its own padded pouch. I received a notification the next day that the product was shipping. The package arrived four days later. Total cost for filter with pouch and shipping to the U.S.A. was $145 — about twice as much as the SharpStar2 (however, you do get a pouch include). I noticed that high international shipping cost outside of the United States for the SharpStar2 tend to raise its total costs closer to that of the FOS filter. For instance, if I lived in Australia, my DHL Express shipping cost for the FOS filter would be $42, for a total cost of $155 (making it only about $2 more in total cost than the SharpStar2).

All-in-all, the FOS filter and pouch were just as described, and nicely packaged. Unlike the SharpStar2, the Focus On Stars filter is made of tempered Gorilla 3 Glass, not plastic, and claims to be very scratch resistant. It was also much easier to clean off my fingerprints and dust, due to a special coating that is applied to the glass.



150mm versions of SharpStar2 and Focus On Stars

I was also able to obtain the larger 150mm versions of these two filters, which I've hung on a clothes line for a visual comparison so you can quickly see the density differences of these two filters. Because of its complex mosaic pattern, the FOS filter is about one to two stops darker than the SharpStar2 (about 0.3 to 0.6 optical density). Will this extra density hinder in your ability to see its star focusing pattern at night, when compared to the more transparent SharpStar2 filter? It didn't seem to be a problem in my field tests (see below).




Actual Field Tests


Preparation

In order to use the SharpStar2 or the Focus On Stars filters, you need to have a filter holder. There are filter holder systems for 85mm, 100mm and 150mm square filters. The most common square filter size is the 100mm. I use the popular LEE100 Filter Holder. You'll also need a lens adapter ring. Many of my Canon and Rokinon astro lens take a 77mm filter size, so I use LEE's 77mm Wide-Angle Lens Adapter Ring for the 100mm System Holder (here are links for 82mm, 72mm, 67mm, 62mm, 58mm and 55mm filter sizes). The Formatt Hitech 100mm Aluminum Modular Filter Holder is also a good system, and is slightly less expensive than the LEE system.

Unless you already have a Cokin P or Formatt-Hitech filter holder system for 85mm square filters, I would avoid this system size, since it has limitations for the more serious amateur or professional photographer; and the Focus On Stars filter is also not available in this size.

Ultra wide-angle lenses in the 14mm, 15mm and 16mm focal lengths typically do not have filter threads because of their huge front elements. These lenses usually need 150mm square filters and special square filter holder systems like the LEE Filters SW150 Mark II Filter System Holder. Another popular solution for super-wide lenses is the Haida 150mm Filter Holder (which is often backordered). Here are Haida holders for the Tamron 15-30mm, Nikon 14-24mm and the Samyang-Rokinon 14mm.

Focusing Procedures with the Filters

The following steps were used in the field with both the SharpStar2 and Focus On Stars filters:
  1. Turned off the autofocus and rotated the lens focusing ring to the infinity mark.
  2. With the camera on a tripod, pointed it at the brightest star in the sky, so that it was in the center of the camera's field of view. The brightest "star" was often the planet Jupiter.
  3. Turn on the camera's "live view" image and magnify the star to the maximum.
  4. Insert the focusing filter into the filter holder.
  5. Manually adjust the focus to cause the middle diffraction spike or diffraction spots (in the case of the Focus on Stars filter) to center between the outer spikes or spots. The symmetry of the pattern ensures perfect focus.
  6. Take a "confirmation" test shot and review the image under magnification.
  7. Make focus adjustments until perfect pattern symmetry is achieved.
  8. When the center spikes or spots are evenly centered, remove the focusing filter and point the camera optics at the scene you want to capture.
These steps worked fine with my 70mm, 50mm, 35mm and 24mm lenses; however, with the 15mm and 14mm ultra wide-angle lenses, even the brightest stars were so small, I had to take these additional steps to get the best pattern symmetry:
  • I often had to rotate the camera a few degrees horizontally on the tripod head until I saw at least two pair of spikes or two rows of dots.
  • I then had to arbitrarily slide the focusing filter, in the holder, up and down until all three pairs of spikes or spots became visible.
Using these additional steps, with the 14mm and 15mm lenses, gave me beautiful diffraction pattern symmetry and perfect focus with the Focus On Stars filter. Seeing and achieving a good diffraction symmetry pattern with the SharpStar2 filter was much more difficult when using ultra wide-angle lenses, as you'll see in the following images.

Field Test Comparisons

Both the SharpStar2 and the Focus On Stars filters produced excellent symmetrical diffraction focusing patterns when using a 70mm lens (a 24-70mm zoom @ 70mm). They both produced good patterns using a 50mm lens (a Samyang/Rokinon 50mm f/1.4). The colorful Focus On Stars pattern is more distinct to my eyes, and easier to judge when it has reached symmetry (perfect focus). However, both products performed well in the 35mm through 70mm range.

Using a 24mm lens (Samyang/Rokinon 24mm f/1.4), symmetry was much easier to see with the Focus on Stars filter than the SharpStar2; however, the SharpStar2 was acceptable as long as you used a very bright star, i.e. the planet Jupiter, and you used a loupe to help you magnify the camera's LCD screen.

The Focus On Stars easily out performed the SharpStar2 when using an ultra wide-angle 14mm lens (Samyang/Rokinon 14mm f/2.8). Even with a 10-power loupe to magnify the back of the camera's LCD screen (already magnified to 10X), it was difficult to see when there was spike pattern symmetry using the SharpStar2. Several image confirmations and slight focus adjustments had to be made in order to get the best pattern. I had virtually the same frustrating results using a 15mm ultra wide-angle lens (Irix 15mm f/2.5).





You'll notice that with the same confirmation exposure, the Focus On Stars image is about a stop darker than the SharpStar2 image. As I mentioned earlier, the Focus On Stars filter is darker due to its complex mosaic pattern. I didn't find that this extra density hindered being able to see or obtain a good symmetrical focusing pattern. Besides, the filter is removed before starting your creative astro photography.

A Work-Around Method to Improve Your Results

The brighter the star (or planet) you use for your Live View focus, the better will be your results with both filters, especially when using the SharpStar2. Even though the SharpStar2 performed poorly with ultra wide-angle lenses like the 14mm, I discovered that using a brighter, man-made "star," such as a Lume Cube 2.0 light, allowed me to produce more acceptable results with the SharpStar2.

My procedure was to place the Lume Cube light about 100 paces from the camera (and aim the light back towards the camera). You can place the light on a rock or use a light stand. This creates a distance of at least 200 feet (61 meters) from the lens—more than enough for any wide angle lenses to optically be at an "infinity" distance. I use a diffuser filter over the light, so that it is no longer a focused light, and I reduce its intensity down to about 10% (go higher, if you still have trouble getting a good focusing pattern).

Because this artificial, man-made "star" is such a higher "magnitude" than real stars, your exposure will only need to be a few seconds, using a low ISO of about 200. This exposure will typically give you greater contrast (a darker background) than real stars in the sky, which should also produce a larger and crisper focusing pattern, even with the Focus On Stars filter—albeit this extra effort is something I find is rarely needed with the FOS filter.



My Conclusions

It may seem ridiculous to spend an average of $108 for a focusing aid (and even more if you don't already have a square filter holder system), but missing one great Milky Way shot due to inaccurate focus will cure you of this opinion, especially when you consider the travel costs you spent to get to a great location.

SharpStar2

PROS: Less expensive than the Focus On Stars filter. A good focusing aid for all lenses up through as wide as 24mm (or 16mm when using an APS-C cropped sensor).

CONS: It is difficult to achieve good results with ultra wide-angle lenses i.e. the 14mm and 15mm lenses (I suspect that 20mm and 18mm lens users will also have some difficulties). Plastic construction makes the filter more susceptible to scratches, and is harder to keep clean. A protective filter pouch will cost you an additional $12 to $20.

 
Focus On Stars

PROS: It is easy to obtain a decisive symmetrical focusing pattern with this focusing filter (apparently due to its more complex mosaic mask), especially with ultra wide-angle lenses in the 14-16mm range. Construction quality is excellent. The filter pattern is sandwiched and sealed between tempered Gorilla 3 glass, making it easier to resist scratches and to clean. A protective filter pouch is included.

CONS: More expensive than the SharpStar2 filter (U.S.A. purchasers will spend almost twice as much for the FOS, with shipping costs, than buyers of the SS2); however, pricing becomes closer for many international purchasers due to less expensive shipping costs (Australian FOS purchasers will pay almost the same total price as SS2 purchasers and European FOS buyers will actually spend less). The inclusion of filter pouch also helps to even out the price difference.

Disclosure: I am NOT receiving any income from the sales of the SharpStar2 or Focus On Stars filters. The links to the LEE filter holder systems are being monetized through B&H. Other than that, this blog post is purely for educational purposes.



Saturday, August 8, 2020

Sony Alpha a7S III is THE Camera for Night Photography




High Sensitivity: "Bigger pixels are better" has long been the motto of the a7S series. The original Sony a7S, which was first introduced in April 2014, has always been Sony's "High Sensitivity" digital camera, with native ISO up to 102,400 and expanded ISO up to 409,600. This camera can literally see in the dark, which also makes live-view focusing much easier than any other camera!

The a7S has been highly regarded in professional video production work as the low-light leader, where it has been used in many famous movies and documentary films that required high quality (low noise) night scenes.
 
Bigger Pixels mean better nightscapes: Except for knowledgeable "nightscape" photographers, only a limited number of still photographers use the a7S series because its full-frame sensor has a modest resolution of only 12.2 megapixels (4240x2832). Those that use this camera for their astro-landscape images claimed that those large pixels are so clean and free of noise that their 12MP images often looked better than other cameras with twice the resolution, when both cameras were shot at the same high ISO's needed for starry night photography.

Most Anticipated Upgrade: The a7S Mark II followed less than 18 months later (Sept 2015) with only a few improvements, i.e. better autofocus and a larger LCD monitor, but the main upgrade was from 1080p to 4K video, which had just become the industry standard. Almost 5 years later, the Mark III is the Sony a7S series' most anticipated upgrade, and most experts feel it was well worth the wait.

Articulating Touchscreen
Optimized for Video — amazing still camera performance, too
: Although the new Sony Alpha a7S III is truly optimized for video, which is its primary application; the still photographer should consider its super fast autofocus performance, sharper viewfinder, articulating Touchscreen, improved noise reduction, wider dynamic range and better image stabilization — especially since the vast majority of still image uses today are for electronic media, not print.

Consider the new Mark III's fast 10 fps continuous shooting for up to 1000 consecutive raw frames and its 5-axis SteadyShot INSIDE sensor-shift image stabilization, which minimizes the appearance of camera shake by up to 5.5 stops. Combined with its increased low-noise sensitivity, and this new camera is capable of hand-held Milky Way photography! Imagine all the low-light night photography possibilities!

Watch this "Behind-The-Scenes" ~ Shot on a7S III


(Expected availability is Sept 24 at $3,498.00)




Tuesday, June 30, 2020

Interview with Nightscape Photographer Marybeth Kiczenski

A tracked, pano-blend exposure in Zion National Park by Marybeth Kiczenski

I recently had a YouTube interview with nightscape photographer, Marybeth KiczenskiThis is my first installment in the "Your Photo Vision" series about how photographers discover their artistic strengths and hone their craft. Future YouTube videos will be behind-the-scenes introductions to some of our NightScaper Conference speakers, and will average about nine minutes in length. You can expect to see a new video at least once a month, so be sure to subscribe to my Royce Bair YouTube channel.






Tuesday, May 19, 2020

Lume Cube Panel MINI Review

Teasel Weed lit with a Lume Cube Panel MINI (@ 10% power) lighting the left side and a regular Lume Cube Panel (@ 5% power, but with cloth filters to reduce intensity) lighting the right side, with an out of focus Milky Way background.

Lume Cube sent me their new Lume Cube Panel MINI light a few weeks ago to review. It definitely is small! At 3.58 x 2.18 inches, it's only about the size of a credit card, and 0.45" thick. Weighing in at only 3 ounces, its less than half the weight of their original Lume Cube Panel and about one-half the size.



The Lume Cube Panel MINI's performance is what impressed me most. For such a small package, it puts out a lot of light. The specs say the 60 bi-color LEDs (30 @ 5600K and 30 @ 3200K) will put out 138 LUX @ 1 meter (although my light meter measurement came in slightly under that, at 120 LUX), which is a little more than one-third the output of its big brother, who comes in at 400 LUX (and my meter confirmed that), using 120 bi-color LEDs.

You might think that 138 LUX is not a lot for serious photography lighting, but in my specialty of Low Level Landscape Lighting, that's plenty of power for most of my work. For many years, I've used the F&V Z96 panel lights at 10% power (about 50 LUX) for landscape foreground features that average about 100 to 150 feet away. The Panel MINI can easily do the same at about 40% power, and with its ability to go down to as low as 1% power for close-distance accent lighting, this makes it a very versatile light for what I do. And, at only $59.95, the Lume Cube Panel MINI is almost one-third the price of the larger Lume Cube Panel ($149.95).

Out of the box, the Panel MINI has everything you need to get started: a slip-on silicon light softening diffuser, a USB-A to USB-C charging cable, a 1/4"/20 DSLR camera mount, and the MINI with a built-in rechargeable 1200mA Li-Polymer battery, housed in a strong aluminum body.



Using the Panel MINI in the field makes you appreciate its built-in intelligent LCD display features. Unlike most of the other panel lights I've used in the past, both the Panel MINI and the original Panel show you its available battery power and run time at any power setting.


Holding down the top power button on the side for 3-seconds turns on the light. Depressing the power button momentarily toggles between power/light intensity and the color temperature. A side wheel-lever (located between the "+" and "-") allows you to change the light intensity between 100% and 1%, in 5% increments. When the light brightness is set to 100%, the run time on a fully charged battery is 1.2 hours, 50% brightness run time is 2.2 hours, 20% brightness is 5.0 hours (shown), and 1% brightness (great for reading in your tent) is 18 hours!  Full recharge time is 1.8 hours. Color Temperature is adjustable by the same side wheel-lever from 5600K to 3200K in 100K unit increments. Depressing the top power button for 3-seconds turns off the panel light.

Mounted or hand-held: I found a lot light painting uses for the Panel MINI, just using the unit in my hand (more examples later this week...). However, most will want to mount the panel in the horizontal or vertical position, using one of the two 1/4" 20 tripod threaded mounting holes. Mounting the panel to the top of your DSLR is easy with the included 1/4"/20 camera mount. This simple setup allows for quick, on-the-move portrait fill lighting, whether you're doing stills or video. For more serious portrait or product lighting, you can use those same threaded mounting holes to secure the panel to a tripod or light stand (that has a male 1/4"/20 threaded screw). For additional light adjustability, you may wish to consider Lume Cube's ball head camera and light stand adapter.

Video Conferencing Light: Many are also using the Panel Mini as a video conferencing light when working remotely. You can purchase the suction cup mount separately to attach to your computer laptop or monitor, or as a package with the Panel MINI.

MORE EXAMPLES IN THE FIELD...



The top image in this foot bridge scene is an evening twilight exposure of 30 seconds, f/8, ISO 320. In the bottom image, just a few minutes later, there's a campfire at the end of the path, and I've walked through the bridge, holding my Panel MINI. I did this about a dozen times, until I got the perfect image. As the twilight began to darken and change color temperature, I had to increase my ISO and change my color temperature. The beauty of the Panel MINI is that I was able to quickly make adjustments to my light in order to naturally match my camera settings.



"Pixie Dust Trail" ~ Both of the images above are 50-second exposures. The top image was taken during the Blue Hour twilight. The bottom image is a blend of that image and this 50-second light painted image, taken about 20 minutes later. During this exposure, I walked the trail holding a Panel MINI that was in a homemade "lamp shade." My lamp shade was made using a styrofoam faucet protector, but you could also use an empty steel soup can. Raising and lowering the lamp shade will change the size of the light coverage. The following photos illustrate how my shade was made and used.




Bokeh Magic: My final photo comparison was to do some street photography, "portrait" style. I employed a technique many cinematographers use: a very "fast," large aperture, medium telephoto lens for an amazing bokeh effect. I used my inexpensive 85mm Rokinon f/1.4 lens (which also has great coma correction for star photography). It's inexpensive because it has no auto focus (true cinematographers often use the cine version of this lens, because it has geared focus). Canon and Nikon versions of this lens have auto focus, but you'll pay about five times the price. Either way, the out of focus highlights you get in the background are truly magical! You can get nice bokeh by shooting wide open with an f/2.8 lens, but the out of focus highlights at f/1.4 are about twice as large and dreamy.

Focusing wide open, with an f/1.4 aperture can be a little tricky at first, even with auto focus. Your depth of focus at portrait distances is often only about a 1/4 inch! Focus on the eyes and the end of the eyelashes are starting to go out of focus. If the head is turned too much, one eye will be considerably out of focus. Despite these challenges, the flattering effect it has on the face is extraordinary, and worth the effort.

Panel MINI portrait lighting: Combine bokeh magic with portrait-style lighting from the Panel MINI, and you have an amazing combination! The only difference between the two photos below is that the bottom image has lighting from the Lume Cube Panel MINI. I've placed the MINI only about 3 feet to my left (to the right of the model), and I've used the silicon diffuser that comes with the unit to soften the light. I was able to dial down the power to 20% and adjust the color temperature to balance with the existing street lighting in this downtown shopping center. EXIF for both images: f/1.4, 1/160 second, ISO 1600 • Rokinon 85mm f/1.4 lens on a Canon EOS 5D Mark III • hand held, manual focus.






Tuesday, May 5, 2020

MSM 2-in-1 Star Tracker Review

"Head on Collision with the Milky Way" ~ a tracked and blended exposure, taken on a lonely road near Buhl, Idaho. The sky portion is a two-minute exposure, tracked with the MOVE-SHOOT-MOVE 2-in-1 Star Tracker. The highway was a separate, blended exposure taken during the morning twilight. The car headlights were one of three lucky occurrences that happened near 4:00 that morning!

MOVE-SHOOT-MOVE is a compact star tracker that also doubles as a time-lapse rotator. I have friends who have bought star trackers and have never used them to take a photo, because they were too complicated to set up! And these are intelligent people. The Move-Shoot-Move is the most compact and easy to set up star tracker I have ever used. From the time I placed it on my tripod to finished alignment was only about two minutes, and within a couple more minutes I was shooting tracked images of the stars. Now I discover it can do time-lapse movements as well! That will be my next outing—however this review will be mainly about its star tracking features.



The MSM Tracker/Rotator is only 3.875 x 3.125 x 1.375 inches (9.84 x 7.94 x 3.49 cm). Weight is only 1.01 pounds (450 g). It's simple 2-button design controls Northern and Southern Hemisphere rotations, full and 1/2 tracking speeds, and four choices of time-lapse movement speeds. Power is supplied by an internal lithium-ion battery that is non-interchangeable, but is rechargeable via a supplied USB cable. Although they claim over 5 hours of runtime, I was only able to get a little over of 2 hours of use during the colder winter months (before a blinking red light indicated the battery was getting low), which is quite typical of li-ion batteries under cold conditions. When I've need longer tracking (or rotator) time, I've plugged in a portable auxiliary USB power source (the MSM will operate while it is recharging or receiving auxiliary power). 

Limitations: The MSM has a maximum load capacity of 6.6 pounds (3 kg), which compares to the popular iOptron SkyTracker Pro and my first tracker, the Vixen Polarie Star Tracker. If you need a tracker that can carry heavier loads and has more available counter balance accessories, I'd recommend the Sky-Watcher Star Adventurer, with its 11 pound payload capacity—however, be prepared for a more intimidating set up (my first experience took me over half an hour).



Here's my personal set-up, using the MSM 2-in1 Tracker/Rotator. I used my own MeFoto ballhead, but MSM's basic "Starter Kit" comes with a similar ballhead (actually better quality than my MeFoto Q1) and a laser Star Pointer for $310.00 (current Holiday Sale price is $239.98). Although you may already have a ballhead lying around like I did, I strongly recommend going with the "Starter Kit" option because these orders are shipped from a U.S. warehouse, and only take about 4 days to get to most continental U.S. locations. Other kit options ship directly from the factory in China and my first order took over two weeks to arrive to my Utah address.

Thru Cyber Monday - November 30, 2020
Get an extra 11% off at checkout when you use the code "ROYCE" (instead of "BLK")



My same set-up viewed from a different angle. The green laser Star Pointer (included with the "Starter Kit") attaches to the MSM unit via a nylon thumb screw and the laser slides into the laser holder, which is secured by another nylon thumb screw. The tripod ballhead is released and the MSM, with the attached laser, are then pointed at Polaris (the North Star), which properly aligns the system (often in less than 30 seconds)! The camera is then attached to the MSM's ballhead via its quick release and pointed towards the Milky Way or a star constellation. The whole process only takes a few minutes.



The green laser Star Pointer makes alignment a quick and uncomplicated process. I found the alignment accuracy to be very good when using any wide angle lens, and even accurate for a normal 50mm lens. My 85mm started to show slight star movement on exposures over 3 minutes, so I'd recommend MSM's optional Polar Scope ($79.98) when using telephoto lenses.

Dim laser beam problem: The Star Pointer comes with a rechargeable li-ion battery and USB charger. I found the brightness of the green laser beam diminished significantly on cold nights. However, by removing the li-ion battery and warming it in my hand or pocket for just a few minutes brought the brightness back to normal strength.

If you live in Australia, I'd suggest you order with the Polar Scope option (Basic Kit A), because laser pointers are not allowed in your country. In fact, anyone living in the Southern Hemisphere might want to use this option. If you travel a lot, you may wish to get both the Star Pointer and the Polar Scope (Basic Kit C).



Comparing Quality: Here's an enlargement from the top image, showing the Rho Ophiuchi cloud complex area. I'm comparing the same area exposed with the tracker off, using a 30-second exposure (click to enlarge for detail). Note how the longer, tracked exposure allows for lower ISO settings, reducing noise and improving detail. Even longer tracked exposures will allow one to stop down the aperture to also reduce lens aberrations. (This 24mm f/1.4 lens gets about a 65% reduction in chromatic and coma aberration when stopped down to f/2.8. At f/4.0, it would lose about 85% of its coma and chromatic problems.)



In this 200% enlargement comparison, you can see that even at 15 seconds, there is some star movement, although it probably wouldn't be too noticeable until one made a print larger than 16x20 inches. What is very noticeable, even in smaller prints, is the huge increase in the number of stars that tracking picks up, and the increase in tonal range (bit-depth) due to the lower ISO's and the light gathering power that a tracker allows your sensor to capture.

How does tracking compare with stacking? I often refer to stacking as the "poor man's answer to tracking." Quickly shooting about 7 to 15 exposures to stack later (with Starry Landscape Stacker or Sequator) will significantly reduce your digital noise, but it won't increase the detail (including the number of smaller stars you'll pick up) and tonal range nearly as much as tracking will.

Orion's Belt and the Orion Nebula ~ a 2 minute exposure without and with tracking (using an 85mm lens).

Pros & Cons: I love the MSM's simple, modular design and its ability to add accessories when needed. I use the laser Star Pointer for most of my tracked shots, and I rarely need the accuracy of the Polar Scope—but it's nice to have it when needed. Ever since I got this tracker, I've been shooting a lot more tracked shot, because it's much easier to set up than any tracker I've ever used. I can't wait wait to start using the time-lapse movement features! My only con is its 6.6 pounds limitation on load capacity, which has never been a limitation for the equipment I use, but might be for some who would want to use a big telephoto lens.

In Conclusion: I think Chris Cook, a MSM owner from Sydney, Australia summed it up best: "The biggest difference I’ve found is the colours which are brought out with longer exposures. A stack of 10 or more photos at 3200 or 6400 [ISO] at 10-15 secs [each] looks great; but, when compared to a single shot at 640 [ISO] for 150 secs, there is no comparison. The star colours are amazing and the nebula are much more noticeable."


Time-lapse Movement Feature: The MSM is a 2-in-1 product that also has four movement speeds to its rotator. This allows for several time-lapse options. MSM offers several tutorials on this, including YouTube videos.

Thru Cyber Monday - November 30, 2020
Get an extra 11% off at checkout when you use the code "ROYCE" (instead of "BLK")