Tag Archives: gear

Exploring Night Photography: Lesson 3 – Gear

Two weeks ago in class we covered basics (what is a photograph, using manual settings) Last week we learned a bit about noise, and its primary causes – temperature being the principle problem. And we explored different creative directions under the umbrella of night photography. We also got outside under a half-full moon (first quarter) and shot on campus. And learned a little about the night sky.

This view is southwest. From left to right are Canis Major, Orion and Taurus. The moon is off the top edge.

This view is southwest. From left to right are Canis Major, Orion and Taurus. The moon is off the top edge. The glow in the lower right corner is the glow bracelet on one of the student’s tripods. The sky remains blue due to the moonlight. Settings for this shot are ISO 800, f/2.8, 10 seconds, 20 mm on Canon 5D II.

Now it is time to talk about gear. Fortunately we already wrote a nicely detailed article about gear. Take a look here. We even updated it recently.

Too busy to read the details? That’s a shame, but here is the super quick summary in order of importance:

  1. GOOD tripod.
  2. Night photography friendly lens (wide angle recommended)
  3. Decent camera body with an optical viewfinder. Full frame preferred, but not necessary.
  4. Layered clothing and good shoes, including lightweight gloves (G) – and heavy gloves in cold season.
  5. Sturdy camera bag
  6. Extra batteries and memory cards
  7. An intervalometer (1), and extra batteries (2)
  8. Headlamp (B) and flashlight assortment (C, 3, 6)
  9. Other needful things: clear shower cap (A), lens cloth, hand cloth.

What About Other “Gear”?

MiscGear
Here is what is usually in our bag besides the camera gear.

  • (H) Glow bracelet/stick to mark the camera location (we have just started experimenting with other methods, too, like the LED band (4).
  • Hand warmers (F and 5) and rubber bands (G) for dealing with dew formation
  • Creative lights – bulbs, keychain lights,  and cord (3, 4, 6, 7, 8, 9)  Item 7 is a green laser pointer.
  • Insect Repellant  (E)
  • Gaffers Tape – flat black duct tape (L). We don’t take a whole roll though!
  • A smart app that shows the positions of the stars, planets, and bright satellites. Also helps if it shows meteor showers.
  • A smart app that shows the location(s) of sunrise, sunset, moonrise and moonset.
  • A game or two on the smart phone to pass time.
  • An external battery to keep our smart phone juiced (5) and the appropriate matching cord.

Before We Leave We Also Use the Following

  • A star map (planisphere). On our desktop, we favor Stellarium, but it is a little geeky to use well. On iOS we like Sky Safari, Star Map.
  • Weather prognostication tool
  • Sunrise/set Moonrise/set predictions.

 

Last Week’s Homework

We asked you to pick a creative direction. Here are some shots our students took including “semi transparent” you, moving lights.

XNP_Alex_assignmentsTop: f/4 1/30, 500 ISO, 20mm; Lower photo: f/4,  1/4, 1600 ISO,  20mm. Bottom was from moving the camera body

 

XNP_Tracie_Assignment

XNP_Troy_assignment

 

This Week’s Homework

  1. Use the light you were given in class to write a message or draw an image in light.
  2. The moon is full, if you didn’t work out settings for capturing the moon. Now is another chance. If you did work out the settings, compare them to your last shot when the moon was half-full. Notice anything?
  3. Find a way to make a strong white flashlight a different color. Use the colored light to illuminate your foreground. Your light may have to be really bright to compete with moonlight.
  4. If you are using a “white” LED flashlight, you’ll notice it is significantly cold (blue). Can you think of a way to make it a warmer color?
  5. Is there any “Other Gear” listed above that intrigues you? E.g. what can you use Gaffers Tape for?

Next… Lesson 4.

What to Look For in a Night Photography Lens

Last Updated: December 1, 2017
Original Publication: Oct 20, 2013

As Numerous at the Grains of Sand

Taken with a 15mm f/2.8 Canon Fish-eye Lens – partially “defished” using Adobe Camera Raw

Obviously here at StarCircleAcademy we love our night shooting. And because many of you love it as well, we get asked a lot of questions about gear: which lens, which camera body, which tripod. To be frank we try not to answer questions about specific gear because there are many tradeoffs that you must consider when choosing. Those tradeoffs revolve around your budget, desire, goals, current equipment, and the mix of photography that you do.

If you’ve already invested $4,000 in Nikon, it really doesn’t make sense for us to recommend a Canon-only lens… and vice versa.  If you do a lot of wildlife photography and only occasionally dabble in night photography an ultrawide fish-eye lens may not make sense in your camera bag.  However, there are some important considerations for night photography that may not be obvious so in this article we are going to tell you what the most important characteristics of a Night Photography oriented lens are… things you may not have considered when choosing a lens for other purposes.

Things that Do NOT Matter

Let’s first set aside a few myths and talk about lens features that get hotly discussed in flame wars on photography boards.  Those include things like:

  • Prime vs Zoom
  • Wide Angle vs Super Wide Angle
  • Rectilinear vs Fish Eye

A lens for night photography can be any and all of the above. Ultimately the question is how good is the lens? Whether it’s a prime, zoom, macro, or not is irrelevant. No lens should be disqualified because it’s a zoom or a fish-eye.  There are theoretical reasons why a well made prime lens will outperform a well made zoom lens… but that doesn’t mean that any given prime will out (or under) perform any other lens. There are dozens of compromises to be made for any lens and some compromises severely hamper the usefulness of a lens at night.

What DOES Matter

Because there is so little light to focus, an autofocus lens is not particularly helpful. In fact some standard lenses that are designed to autofocus are notoriously difficult to get focused at night. Here are the considerations we believe are most important, roughly in priority order:

  1. Usable Aperture
  2. Manual Focus & Maximum Sharpness
  3. Accurate Lens Markings
  4. Minimum Distortion and Coma
  5. Limited Vignetting
  6. Build Quality (Mechanical reliability and sturdiness)
  7. Weather Sealing
  8. Dew Shield/Lens Hood
  9. Cost

Usable Aperture

A lens that tempts you with an incredibly fast aperture of f/1.2 is all but useless if you have to stop it down to f/7 to make it acceptably sharp. Usable Aperture refers to the maximum aperture at which you can make exposures that you would be proud to hang as poster sized prints on your wall, and yes, that is very subjective. In night photography, as in astronomy, aperture wins.  The more light a lens can drink in, the more stars and dim details the lens can capture.  The f/ number is a ratio of the size of the front glass to the focal length of the lens. That means that the larger the front element, the more light it can drink – all other things being equal.  There is no substitute for “fast”.  Another advantage to a fast lens is that you’ll get more detail in your viewfinder.  You may be able to make out foreground objects in an f/1.4 lens that will be entirely inscrutable at f/4.

A zoom lens may have a variable f-stop ratio. This may be a detriment. If the ratio changes, e.g. from 2.8 to 4.5 then you’ll lose quite a lot of light when you use the zoom.

Manual Focus & Maximum Sharpness

Sadly, lenses designed to autofocus quickly are often the worst choices for night photography. Take the Canon 50mm f/1.4 lens, for example. The amount of play in the focus ring is miniscule so manually adjusting focus for a night shot is a lot like trying to peel a grape while wearing mittens. A tiny 1/128th of a turn takes the shot from out of focus in one direction to out-of-focus in the other.  The lens, therefore, is only usable if there is enough light to get it to autofocus before taking the shot.  By contrast nearly all manual focus lenses are designed to allow plenty of room for focusing. A Rokinon 24mm f/1.4 allows me to turn the focus ring almost 360 degrees to adjust the focus.  That is a big plus when you want to get focus just right – it also means that slight errors in focus are less drastic. Avoid a lens that does not have a manual focus ring. Unfortunately more and more of the kit lenses are dropping the manual focus ring and lens markings.

Accurate Markings

A lens with nicely tunable manual focus is not so nice to use if you can’t start close to the correct focus location.  Many really cheap lenses have done away with the lens markings all together. We recommend you avoid those lenses.  An accurate marking may allow you to dial and shoot without having to check and recheck focus. That can be a time and patience saver.

Minimal Distortion / Chromatic Aberration

No lens is perfect. If you found a perfect lens, you will have paid an enormous price for it. Every lens must make trade-offs. Some of the less desirable trade-offs for night photography include coma – bird wing or “comma-like” stars most notable in the corners of the frame and at wide open apertures. My expensive Canon 16-35mm f/2.8 L II lens has pretty awful coma in the corners.  That doesn’t mean I don’t use the lens, it means when I want the whole field of view I need to either stop down to reduce the coma, zoom in, or plan to crop:  all compromises that are unpleasant – but – my work with the 16-35mm lens sells just as well as with other lenses and it is a sturdy, well made lens.

Chromatic aberration – color fringing – is also a common distortion problem. Sometimes night shots reveal chromatic aberration more significantly than any other shots because of the sharp differences between say a bright moon and a dark sky.

Ghosting and flare are two other villains that produce strange artifacts on your shots.

Finally there is distortion due to the lens geometry. For example, fish-eye lenses render elements at the edges of the frame with odd curvature. Sometimes this is a really pleasing thing, sometimes not.  Fish-eye lenses also often suffer from “Mustache” distortion which causes a strange bowing of the bottom middle of the frame. Other standard distortions include pincushion and barrel distortion where the center of the image appears to be shrunken or enlarged. Many of these distortions can be corrected in post processing – but that doesn’t mean the image is going to be perfect.

The one distortion I despise the most is coma. Second most: chromatic aberration.

Minimal Vignetting

If you want to use the whole field of view, it’s not helpful if the corners are two or three stops darker than the center of the frame.  While the correct term for this phenomenon is light fall off, most people know it as vignetting. Picking on the Canon 16-35mm f/2.8 L II, it vignettes heavily at 16mm.  I find I have to zoom to 17 or 18 mm to reduce that effect. As with other distortions noted earlier, some post processing can remediate, but not eliminate the vignetting.

Other Obvious Tangibles Common to All Lenses

  • Build Quality
  • Weather sealing
  • Dew and/or Lens Hood
  • Cost

A well designed lens hood is very useful for keeping off-axis light out of your shot and protecting the front element from damage and dew. A lens hood is more important in night photography than in daylight!

Keep in mind that lenses generally hold their value very well. A lens you pay $1000 for today will probably be worth that much or nearly as much (or even more!) in 3 or 4 years. By contrast, your camera body will probably be worth less than half of what you paid for it because a newer, more featured, more powerful body will have replaced it. In the old days you could get better pictures by taking your good camera and putting better film in it. In the digital world the better film comes at the cost of a new camera.

Astrophotography Equipment Follow Up

Andromeda

New Equipment vs Old

In the years since I began writing about astrophotography techniques and equipment (including review of the Polarie, pointing tips, and processing techniques) things have obviously changed for me.  For one, I’m not working at astrophotography as hardcore as I expected.  The reality of managing an informative website (this one!), creating publishing and supporting tools, conducting fairly frequent expeditions and workshops, writing and improving content for webinars *AND* having a day job means I have to temper my enthusiasm. Or to say it more plainly, have my enthusiasm tempered by reality.

However a student asked me this question and I felt it was a good topic. The question:

I read your review suggesting the Orion Astroview EQ mount with optional dual axis motors. I’ve been looking for a cheap way to do decent tracking and have considered making a homemade Barn-door mechanical tracker to something more reliable (motor driven).

On Orion’s website, I find their Astroview EQ mount (#09822) and the dual axis motors for the Astroview (07828).

Soooo, my question is this: Since you wrote that article, is that still the most bang for your buck, or have you found something better/bigger/cheaper?
— Bruce L.

As I noted in my article, there are definitely bigger and better and significantly more expensive things … though nothing cheaper that I’d recommend. The Polarie is in the same price league.  After I made my recommendation my Astroview suffered a series of blows to the declination drive that rendered the drive useless.  The first blow was that the locking nut fell off in the dark and was lost. Once I replaced the lost piece (at about $35) the next blow was quite literal and it bent the drive axis rendering the motor useless. The truth, however, is I really didn’t need the second axis at all and I’d have saved a few bucks by only buying the single drive motor to begin with.  The Astroview is just beefy enough to carry the weight of my Orion 80ED refractor and a camera.  And to be quite honest since it is lighter and not a “GoTo” mount it’s actually easier to set up and take down than it’s bigger cousin, the Sirius mount. But the Astroview is nowhere nearly as well made.  So yes, I’d still recommend an Astroview as a minimum viable solution… provided you stick with a camera and telephoto / normal lens to do imaging.  Most telescopes worth mounting on the Astroview will cross the boundary of what the Astroview is designed to carry and will be too heavy for good operation.

Automating Focus – Two Steps Forward, One Step Back

I had upgraded the focuser on my 80ED to one sold by ScopeStuff (#RNFR) – a $320 motorized focuser. That focuser proved easier to use and more versatile, but I later found it coming apart and it required some heavy tinkering and investigation to get it working again.  I also realized that the system was not that well thought out – it was designed to have the motor base mounted to the focus TENSIONING screw rather than attached to a fixed screw on the focuser.  That’s probably in part why when I got it, the tube would not travel all the way through the almost 4 inches of focus. I’ve restored it to operation but it still won’t travel in the final 3/4 of an inch… that’s fine, however as I have never needed that much in-focus – I’m usually working with the focus tube nearly fully extended.

In focus - moving the camera inward, toward the front element of the telescope, thus shortening the overall length.
Out focus (aka back focus) - moving the camera outward from the front element lengthening the apparatus.

Is A Barn Door Tracker A Good Solution?

Let me address the question about a Barn Door Tracker.  There are no places that I have found to buy barn door trackers, it’s strictly a home-built type of thing. As I explain in the Astrophotography 101 webinar, a barn door tracker is a form of an equatorial mount that has been simplified to drive only one axis (the right ascension) and with a limited tracking time.  Various designs like the double arm version improve tracking accuracy while complicating assembly. My personal bias is that even though I’m pretty handy with tools I’d rather spend $400 on a fully built system than $80 on parts and 10-20 hours of my own labor building and perfecting the system.  I suppose if someone handed me a robust kit for $100 and told me I could assemble a motor driven barn-door tracker in an hour or less, I’d give it a try.  But at much more cost in time or money the barn door tracker starts bumping into fully built solutions like the Orion Astroview and the Vixen Polarie or the iOptron SkyTracker.

One of the principle impediments with all things astrophography – and part of the reason I created the Astrophotography 101 course is that there is a LOT of language used that is foreign to most people. And, there are legion of difficult choices to make. For example, I recently bought a William Optics Telescope. It is a well built, heavier than expected, refracting telescope that features a power focuser. Perhaps as a surprise to the uninitiated the “power focuser” is not actually powered (motor driven), it is an improved version of the manual Dual speed Crayford focuser and the term “power” implies it’s ability to hold focus without slop or creep – even if the other end of the focus mechanism is a pretty substantial camera.

I had hoped my existing finder scope and guide scopes would easily attach to the new William Optics telescope, but they won’t. The fittings are all different. For the most part astronomy and astrophotography equipment is a wild west of non-compatible, non-interchangeable components.  Much like you see if you try to use a Nikon lens on a Canon camera.  Or an intervalometer built for a Sony on a Lumix camera.  The difference, at least to my way of thinking, is that the compatibility of components is much better spelled out in the camera world than the astronomy world.

What about the Polarie?

The Polarie will work well with normal lenses. When I mounted my 70-200 with a 1.4x and the Canon 5D Mark II (or 40D) on the Polarie, tracking accuracy was pretty bad – but not directly because of the Polarie. The problem is that the systems is not balanced and there are three different points around which the apparatus gets sloppy: at the connection between the ring-collar of the lens and the head mounted on the Polarie. At the point where the head is attached to the Polarie screw, and where the “collet” with it’s two thumb screws attaches to the Polarie.  Invariably one of those would become loose enough that it would slip.  I found that putting a counter weight at the end of the lens reduced slipping and improved the tracking – but it’s a hassle and highly dependent on where you aim.  A true equatorial mount is easier to balance. The Polarie system works better when there isn’t a lot of torque around those attachment points.

In summary, I like and use the Polarie because it’s compact, light, not bulky and easy to take with me literally anywhere I go. But I would not use it to take serious astro images.  The Polarie best fits Landscape astrophotography.  For example, below is a 63 second exposure using a Canon 40D at 1000 ISO, f/2.8 at 16mm.  Using the 500 rule, star streaking would become apparent at about 12 seconds.  In this small size there is nothing at all visible, but do notice how the foreground head frame at Bodie State Historical Park is blurred – that’s because the Polarie was tracking the sky at 1/2 sidereal (star) rate. The photo has been exposure enhanced (brightened) to see details, and noise reduced a bit.

B_180-002309_sm

 


Here is an exposure that is a bit more germane. Two exposures, actually. One focused for the hand-lit tree, the other focused on the stars and both were combined in Photoshop.

Heaven Bound [C_075698+701]

Top Ten Reasons to Do Night Photography

I presented this list the Palo Alto Camera Club recently. Much thanks to them for being a wonderful audience and for the opportunity for Harold Davis and me to speak.

Docked [C_050127+]

10. Night photography takes time so you get a free lesson in patience.

9. You can’t use the meter so you really DO have to learn how to take photos.

8. Lots of challenges to overcome = excitement for geeks and engineers (and some normal people, too).

7. You can refer to yourself as the CRAFTER of LIGHT (if you want).

6. The camera sees all: including colors at night.

5. Automation makes night photography almost easy.

4. An excuse to upgrade: I’ve GOTTA get better high ISO performance!

3. You have PROOF that you were behaving when you were out all night!

2. You don’t have to give up your day job to do night photography.

1. Is there a more fun way to meet people in the dark?