Sigma 50mm F1.4 DG HSM Art First Impressions

May 13, 2014 by

I’m constantly looking for better lenses at my favorite focal lengths, and when Zeiss had announced that they are making an über 55mm lens, it immediately appeared on my shopping list. Its $4000 price while not prohibitive, I have very high expectations at that price point. And the Otus fails at two of them. I don’t think that the open distance scale is a good thing to have when I’m out in the field (except for generating trips to the service), and for $4000 I would expect 11-12 rounded aperture blades and perfectly circular aperture all the way down – like on cine lenses in this price class.

So I became very excited when Sigma’s new Otus competitor was recently announced. I read every possible review on the net (just to realize how shallow these became during the last years), and actually ordered the lens without having a solid idea how will it perform.

My copy finally arrived yesterday. I spent an afternoon on comparing it with my former 50mm lens of choice, Canon’s EF 50mm f/1.4 USM. Well, I can attest that most of the hype about the Sigma 50 Art is true.

Sigma50-5D3

Simga 50mm F1.4 DG HSM Art on the Canon 5D Mark III

I’m going to use this lens for landscapes as well as for astrophotography. While f/1.4 isn’t necessary for traditional landscapes, it definitely opens up new creative possibilities. And for astro, wider usable apertures are a must. The Canon 50/1.4 isn’t really usable until f/2.8. It’s a pretty solid performer at f/4 and up, but forget about making high quality images wide open.

The Sigma is in a different league wide open. At f/1.4 it’s a bit better than the Canon at f/2.8 – and while the difference becomes smaller, there’s an edge to the Sigma at every aperture. The Sigma is a pretty damn sharp lens. And this was one of the things I was looking for.

Its high contrast also increases apparent sharpness. But high contrast is not necessarily a good thing. It’s easy to increase contrast during post-processing, but plugged shadows and burnt highlights are not that easy to deal with. I read somewhere that the engineers sacrificed a little sharpness for increased contrast – personally I would be happier with a sharper and less contrasty optic. Given the shadow-challenged nature of Canon’s current sensors, I will need to keep an eye on the shadows constantly.

Color rendering is brutally different. Reds and especially greens come alive with the Sigma, where I needed substantial amount of work with the Canon during post. Shadows are also clean, no yellowish-brown tone to them. Overall colors are on the colder side – not something that can’t be corrected in post easily.

Except for the colder color, the 50mm Art reminds me to the magical Canon EF 135mm f/2L USM. That is, they are of similar size, similar weight, similar materials and build quality and produce similar superbly clean and detailed files. Yes, this isn’t your small and light 50mm – but are perfectly in line with other high quality primes in my bag (the 135 and the TS-E 24mm f/3.5L II). It’s not something I would bring to a vacation, however. The Canon 50/1.4 is a much better option for that.

I haven’t checked autofocus yet, as I plan to use Sigma in manual focus for 95% of the time. For manual focus, I would prefer a longer than 92 degree focus throw. I suspect that AF would be slowed down too much with longer throw.

What else could be improved on the 50 Art? Well, I would be happy to spend a few hundred more and get weather sealing. Rubber materials are a dust magnet on this lens, so a less dust attracting material would be great…

I’m very impressed with this lens. Something I didn’t feel since I got the Canon 135mm f/2L. At $950 it’s a steal (again, like the 135mm). If 50mm is something that makes your world go around, I highly recommend to give the Sigma 50mm Art a try.

Filed Under: Photo Equipment Tagged With: , , ,

Which Lenses Do You Recommend?

May 11, 2014 by

I get asked the above question quite often – only “which camera do you recommend?” being more popular.

Well, this piece isn’t the all too familiar “this is the best lens you must own, and here’s a link to buy it – which earns me a small commission” type. I’m not going to recommend any single lens here. But I will give you some tips on how to get an answer for this question from the only authentic source – yourself.

With freedom comes responsibility

The sheer amount of lenses available for a single mount could be overwhelming. For example Canon offers no less than 76 EF/EF-S lenses at the time of writing. And this does not include 3rd party offers from other manufacturers like Sigma and Zeiss.

The Canon lens lineup at the time of manufacturing the 100 millionth lens. Image courtesy of Canon.

The Canon lens lineup at the time of manufacturing the 100 millionth lens. Image courtesy of Canon.

There is a popular – but false – wisdom that you should cover every possible focal length. Just in case you need it. I must admit that as a newbie I fell into this trap too…

But why this trap exists in the first place? Because going this way is easy. It’s pretty damn easy to pick up two or three quality zooms and be “covered”. I’m not saying that zooms are inherently bad. There are situations (when your movement is restricted and/or you can’t change lenses) when they are indispensable. I’m just saying that picking up zooms on the idea of being “covered” is a bad method of choice.

Also zooms are great for my mom, but if you are serious about photography then you should be serious about angle of view – and thus lens – choice. That is, you should make informed decisions about the lenses you use. No, you shouldn’t trust and rely on information coming from the outside (blogs, friends, etc). You must check and evaluate your own work and yourself continuously and correct the mistakes along the way. Believe me, you will make lots of mistakes – but those will teach unforgettable lessons about your vision and your personality.

The goal is to find the glass that matches you vision. Both in angle of view and character. Yes, you’ll need to work and experiment a lot. But it will be fun!

Matchmaking tips

The following is a list of tips and techniques I found incredibly useful in evaluating my own work and vision. Chances are that they will also help you.

Borrow or rent. You have to see it yourself. You can’t trust reviews on the net. So instead of buying a given lens (which may or may not fit your vision) it is more economical to borrow one from a friend or rent it. But more important is to do some real work with it! Brick walls and pets doesn’t count (unless what moves your world is either brick walls or pets, of course). Use the lens for a handful of shoots. But do it at least in two sets, a few weeks apart. Evaluating the resulting images on the camera’s LCD also doesn’t count. Process them. Print them. Use them as you normally would use any of your images. If you can’t make a single good image with the lens, then it doesn’t match your vision, so it’s better to let the given focal length go. If you think that usability, max aperture, or any other aspect sucks, then look for an alternative with the desired parameters.

Simulate. Especially useful when you can’t borrow or rent a lens, or for first quick checks. If you have an iPhone/iPad/iPod, my Artist’s Viewfinder app lets you simulate viewing angles for tons of different camera and lens combinations. Or you can tape down the zoom ring on your existing zoom to simulate what it feels like to shoot with a prime. Or crop a wider image in Photoshop. With simulation you can get a feel, but don’t forget that it’s not the real thing. You should have the lens in hand to do a final check whether you match or not.

Check your existing work. This is a pretty powerful thing. As metadata in digital images record the focal length they were shot with, you can check your previous images whether you like or dislike a given focal length. Only finished work counts, however. You will have countless images with any given lens classified as crap. Don’t let them deteriorate the results. Also don’t forget to account for format differences! In my case, digging in Lightroom’s database revealed a (then) surprising fact: even if I used zooms, all my finished landscape images were clustered around three major focal lengths: 24, 50 and 135 mm (in full frame 35mm terms). It’s not a surprise now (four years later) that these are the focal lengths I always carry.

Buy the best you can afford. Great lenses will be with you for 10-20 years, or even more. They also tend to keep their value. But most importantly, they match your vision and style, and thus are vital to your work. Do yourself a favor and don’t be cheap! You’ll be grateful 20 years later…

Filed Under: Photo Equipment Tagged With:

What’s New in the Mark II AVF 3.2 Update

March 11, 2014 by

The latest update to the Mark II Artist’s Viewfinder went online earlier today. Besides the usual slew of newly supported cameras and backs (listed in the press release), there are two feature groups I’d like to talk about. Let’s begin with new customization features.

Original Viewfinder editions had a completely neutral main screen. While the Mark II’s red/white toolbar looks pretty neat, a few users complained about the vivid colors interfering with their composition. So in the 3.2 update you can switch the toolbar into a dark and neutral themed one. It’s interesting to note that it brings a completely new character to the main screen – but still looks neat.

dark-toolbar

The new Dark & Neutral toolbar theme

Speaking of distractions, a few of you found the translucent white AF/AE point indicator distracting. You can now turn it off if you wish. But please note that the red circle will still be displayed when AF is in progress.

We also received requests to make “more Fn Keys” – that is to let the user customize the function of other toolbar buttons. And beginning with version 3.2 you can override the EL and FL buttons with the exact same functions that you can assign to the Fn Key. You’ll lose their initial functions while the override is active, of course.

Finally I was able to put my hands on the iPro lens system case for the iPhone 5s, so this update rounds out the supported wide converter/device combinations with both Schneider converters on the iPhone 5s. And also adds the Cambo WRS-1060, which utilizes the Schneider wide lens.

A fix for the “gray screen with no live view after switching to another app and back” bug is also included. While fixing this, I ran into a more serious issue: with toggling exposure lock on and off on the iPhone 5s I was able to bring the phone’s entire video capture system down to its knees. We are working on a fix with Apple, but the interim solutions is to restart live view when you disengage the exposure lock. I know, it’s a bit of pain, but there’s no better workaround yet. The good news is that only the iPhone 5s is affected.

The Viewfinder Handbook has also been updated to cover these new functions.

Filed Under: My Apps, Photo Software Tagged With: , , ,

Building an Astrophotography Rig

February 27, 2014 by

Building an astrophoto rig is like building a custom motorcycle: it’s expensive, time consuming and involves a lot of DIY. There are some outstanding parts available, but assembling them into a great tool isn’t trivial. You have to do lots of research. I decided to share my experiences along the way as I build my setup – and this is the first installment.

When I started this project, my goal was to be able to utilize the great primes in my existing lens collection and share the equipment to the greatest extent possible with my regular photography toolset. So there’s no telescope involved – I use my 500/4 instead for deep sky objects.

650D_1409_5103My current rig (with the 500 installed) is on the left. Let’s forget about the camera and lens for this post’s sake, and concentrate on what’s below them.

Basic Support

The central part of this setup is the tracking mount, which compensates for Earth’s rotation. This is a mandatory piece of equipment if you want to use anything other than wide angle lenses and short exposures.

I decided to go with the AstroTrac TT-320X-AG. This is a “barn door” type mount, where two arms open up like a scissors. This device is small and light, and provides the tracking accuracy of regular equatorial mounts weighing 20x as much or more.

Of course the AstroTrac is in equatorial arrangement: you have to align its rotation axis with Earth’s. To allow precise alignment you’ll need a geared head between the tripod and the tracker. A ball head won’t do it. AstroTrac also makes a head, called a wedge is astro parlance, the TW3100. This provides great controls for very precise adjustment and is lightweight.

A heavy-duty, stable tripod is essential. Fortunately it is not a new requirement for me – and I use a Gitzo 3532LS. This is a great tripod, and the ability to rotate the top plate is godsend for rough tracker alignment. To improve stability I extend only the upper (thicker) leg section and hang a beanbag on the top plate’s hook.

The top plate of the tracker is the home of my regular ball head, an Arca-Swiss Z1sp. With a breaking point somewhere around 50-60kg, this head can easily support even the 500mm lens. Just have to be careful with loosening the knob when the 500 is mounted.

Powering the AstroTrac

Well, this was the point where things started to look ugly. The AstroTrac mount needs 12V DC. They sell a very basic (read crap) AA battery holder, but using alkaline AAs is a no-go in my book. So I needed a rechargeable 12V power source. First though about using ten AA NiHM batteries (again, in a crappy holder), but charging lots of AAs is a pain in the butt. Another solution would be to use a 12V car battery. There are lots of car battery based astronomy targeted power sources around, but they weigh several kilograms – definitely not on the portable side.

Surfing the web for hours I ran into Tracer’s lithium polymer battery packs, and ordered the 4Ah model immediately. This is the block you see on the lower left corner of the above picture, Velcroed to the tripod. It sports a 12V cigar lighter plug, which connects with the AstroTrac’s fused cigar lighter cable.

This battery provides enough juice to run the tracker for up to 16 hours, and weighs just 330 grams. Problem solved.

Polar Alignment

To help in precise polar alignment, a polar scope is needed. And this is the weakest offering in AstroTrac’s product line. The tracker and the wedge are great, well built products, but their polar scope is a bad joke. It has an illuminated reticle on which you have to place three stars in marked positions. But this reticle is not collimated (centered) in the factory! To make things even worse, collimation can be done with three tiny grub screws – a totally unusable solution. Even after I replaced them with thumbscrews, I had to re-collimate it quite often. Another issue is that this scope is held in position with three tiny magnets. Just a small breeze, and the scope will fall. A small amount of pipe insulation around the scope solves this, but nevertheless this scope is sub-par. I had to look for a replacement.

650D_1409_5122And that was a competing tracker’s polar scope, from the Vixen Polarie.

Of course it won’t fit into the AstroTrac’s polar scope arm – the base of the Polarie scope is just 0.5mm wider that the hole on the polar scope arm.

My father machined a custom adapter that not only holds the scope in place, but I can screw it in securely.

Alignment with the Polarie scope is also easier. Much easier. Just set the current date, time and meridian offset on three dials, and place Polaris into the marked position on the reticle. Quick and easy.

The only downside is that the Vixen’s reticle is not illuminated, and you don’t see the markings by default. So I cannibalized the AstroTrac scope’s red LED illuminator, and shine on the front lens of the Vixen scope while doing the alignment. The background turns red, markings become visible, while I can still see Polaris well.

With the Polarie scope I can polar align the rig in just a few minutes – every time. It’s a difference like switching to a Mac from Windows.

Update 2/9/2015: now I’m using a much better solution with another Vixen polar scope.

Conclusion

I’m very happy with this rig. Polar alignment with the scope only is good enough for 2 minute exposures with the 500mm and the 5D Mark III – it might be good for even more, I just haven’t tried yet. For wide field work it’s more than enough. My only issue now is the number of clear, moonless nights…

  ☕ ☕ ☕

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Filed Under: Astrophotography, Photo Equipment Tagged With: , , , , , ,

First Take on Orion Nebula

February 26, 2014 by

Last night the conditions were favorable to try my Canon 500mm f/4L IS lens for astrophotography. I was interested in the maximum exposure length with only a simple polar alignment (with no time-consuming drift alignment). Also wanted to check out any other issues that might arise from using such a heavy lens.

Well, it turned out that 2 minute exposures were good, so I made a series of 2 minute, 1 minute, 30 second and 15 second exposures. 35 in total – the shorter ones to be able tame the bright core of the nebula. When I loaded the images onto my computer half an hour ago, I realized that focus drifted horribly after the first three frames… I suspect the rapidly falling temperature being the cause. Temperature change induces a focus shift. That’s why you can focus lenses “beyond infinity” – to compensate for this shift.

So it turned out to be an exercise in recovering what’s possible in such a badly screwed up situation. Below is what I could recover from these three frames. I was surprised that the overall result is pretty good, just disappointed about the overly bright core.

OrionNebula-3frame

M42

Because refocusing between frames is not a viable option (think image position changes and lack of bright enough stars), I’ll look into telescope heaters… I’ll let you know when I will have a working solution.

Filed Under: Astrophotography, My Photos Tagged With: , , ,

Viewfinder Handbook 2nd Edition

February 15, 2014 by

IMG_0470The wait is over… I managed to finish the new edition of the Viewfinder Handbook yesterday, and now it’s available for download.

Partly rewritten and expanded to cover version 3.1 of the Mark II Artist’s Viewfinder and ALPA eFinder II. I would recommend it to both new users and veterans of the old app — as the Mark II brought lots of changes.

New main screen, wide converter support and simulated equipment setup (now called virtual cameras) being the three most important areas.

The handbook is a 14 MB PDF file, optimized for viewing on iPads. But because it’s a PDF, you can read it on any device, be it a tablet, a Mac or a PC, and in numerous PDF reader applications.

It can be downloaded free of charge from the Mark II’s web site.

Filed Under: Books, My Apps Tagged With: ,
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