equivalence is more equal than you think

There is a perpetual online discussion amongst measurbators about “equivalence”.


Equivalence is a very real phenomenon which can be predicted and measured.  The idea is that when comparing cameras with different sensor sizes, smaller sensors tend to have greater depth of field at “equivalent” focal lengths.


Why “equivalent” focal lengths?  Ok, it gets technical pretty quick, but rather than bore you with esoteric technobabble, lets just look at some images.  (Photography is about making images, right?!)  If you feel that the differences are drastic, then by all means read on.  But if none of these images strike you as dramatically different from one another, just know that you can safely ignore anybody who ever mentions “equivalence” or “equivalent apertures”.  Because they’re either trying to waste your time or sell you something.  (hopefully I’ll have saved you from the clutches of some forum troll)


Here they are:


MG2_3230 P1060916

This is what the war is about.  A mountain of a mole hill, idn’t it?


So what are these earth shattering differences due to?  Sensor size.


Sensor size has an effect on many things about the final image a camera can produce.  The least of which is probably depth of field.  Generally speaking, the larger a sensor is, the shallower the depth of field is.  The top image was shot with a Nikon D700 (36x24mm sensor), the second was with a Nikon D7100 (~24x16mm), and the last is shot with a Panasonic GX1 (~18×13.5mm nominally–however this was shot in 2:3 aspect ratio, so really about 18x12mm).


Why is this important?  Because to get the same framing with cameras with different sensor sizes, one needs different focal lengths.  The first image was shot at 200mm; the second at around 125mm, and the third at around 95mm.  These were all shot with the same zoom lens, wide open at f2.8, adjusting only the focal length.  In fact, I didn’t even move the lens–I just mounted it directly to a tripod and swapped cameras with the lens in place.  (sorry, it does appear to have wiggled a little from shot to shot).


Focal length is one of the main ingredients in determining depth of field.  The other is aperture (Aperture is…a complex topic.  For more, just read here: https://en.wikipedia.org/wiki/Aperture).  Since aperture was fixed from shot to shot, all the difference in DOF is due to focal length.


Because of the differences in sensor size, to get the same framing with each of these cameras, one needs to utilize different focal lengths.  For instance if one is using an 85mm lens on a “full frame” camera (aka 35mm, aka FX, aka 24x36mm sensor), one would need to use a 42.5mm lens on a Micro 4/3 system camera to get the same framing.  But if you used the same aperture setting on both, the 4/3 camera would look a little different–a little bit more would be in focus.


If one knows anything about photography, one knows that if you want shallower depth of field, one just “opens up” their lens.  You use a larger aperture.  If the full frame camera is shooting at f4 and you want exactly the same look, you shoot at f2 on 4/3rds.  No big deal!  Right?


Well the issue is that all lenses are subject to the same design limitations, and that means that the largest apertures commonly seen on lenses are 1.8, 1.4, and a rare 1.2 here and there.  And this is regardless of sensor format/mount.  85mm lenses for FF and 45mm lenses for 4/3rds are both readily available, but only at the same apertures.  And to reproduce the look of an 85mm f/1.4 lens on a D700, one would need a 42.5mm/f0.7 lens, which is practically non-existent.


In short: you can’t buy lenses for the the 4/3rds system that will give you exactly the same look that you can get with a “full frame” camera.  You’re not likely to see a 35-100/f1.4 lens for 4/3rds, which would replace your 70-200/f2.8 on your full frame camera.  Not in the near future at least.  Maybe in the distant future.  If ever.


And that is a reason people constantly use to deride smaller sensor cameras and their users as less than professional or inferior in some way.  And by “people” I mean the the marketing departments of companies that don’t make small sensor cameras that are very competitive (aka Nikon and Canon).  And measurbators in online forums.  (aka TROLLS)  Well, maybe they’re not trolls per se.  Just people with inadequacy issues, trying to justify a purchase (maybe one already made?).  Or sufferers of GAS.  (Gear Acquisition Syndrome)


There are many reasons that the Micro 4/3rds system can’t replace my larger sensor DSLRs today.  But “equivalence” ain’t one of them.  m4/3 is actually competitive for a lot of good reasons right now: price, lens selection, features, image quality, video capabilities.  Even the weakest points–autofocus and resolution–are really not so far behind the best gear.


Is there a difference in DOF between these three cameras?  SURE!  Is it a big difference?  I dunno.  You tell me!

The racism of photography


True story: modern cameras are racist. Most slide film, with it’s high contrast, was as well. “Kodachrome has great skin tones” was only true for white folks. Digital has actually been better at this for at least 10 years. But not at high sensitivities, and not always with video. And video is tougher to correct in post.



Phone photography

So I happened upon an amazing piece of software for basic adjustments and manipulation of photos on Android devices, called Photomate R2.  It’s a lot like the ACR/LR engine, perhaps with a little less refinement.  But it handles true raw files, and it’s the only Android app I’m aware of that does so.


So I’ve got that wrapped up.


What I haven’t figured out yet, is an app that will allow me quick manual controls of the camera actually in my phone.  Something that will simple direct control of things like exposure/ISO/aperture/WB.


Does such an app exist?


Want lens flare and bokeh like the last Star Trek Movie?  This is the single piece of gear you need to accomplish that: http://www.slrmagic.co.uk/slr-magic-anamorphot-133×-50-anamorphic-adapter.html


Seems like their lenses have been pretty solid for video work, so this may be worth checking out.  Of course there’s always the old budget versions kicking around too.


Edit: looks like some folks have a sample vid up already: https://vimeo.com/86774077

Is your lens busted?

I’ve just had my first absolutely awesome experience with the Nikon USA repair department (all previous ones having been abysmal). They did a bang up job (for a price!) of bringing my many times dropped 70-200mm VR (V1.0) lens back to spec. And the proof is in the images!


This was shot with the 70-200mm, a TC14E, and a crappy Tamron 2x extender, on a D7100 (for a grand total of 840mm equivalent in 35mm) and it STILL looks good (in my opinion)


I’ve never personally sent a lens in for repair to Nikon–only bodies. And we all know how bad that went!


So with my first decent Nikon repair in hand, I was surprised to read this article by the venerable Roger Cicala over at Imaging Resource: http://www.imaging-resource.com/news/2013/11/14/inspecting-an-in-spec-lens-what-does-it-mean-and-could-factory-service-be


Perhaps I got lucky? Or they do a bang up job when it’s on my dime? Or maybe Nikon actually has some good test gear for lenses, but not bodies? Time will tell, since I still need to send my 17-55mm lens in!

a trick to clean your mirror

I just discovered something awesome. Maybe this was obvious and everybody else knows about it, but just in case you don’t: I used a sensor swab to clean a DSLR mirror.* Really wet, really gentle. And now REALLY clean! AF even improved!

*Try at your own risk! I am not responsible for any damages to your camera.

A win for DSLRs and people who enjoy concerts!

— Micah (@photomicah) July 9, 2013

I’ve been complaining about being hassled at concerts for a long time.  Especially when they’re expensive ones.  I’m incredibly discreet with a DSLR, and others are taking pictures with their phones anyway…why bother me?

More here at Imaging Resource.

Olympus Stylus not so Tough

The “Olympus Stylus Tough 3000″ is not so tough inside. The zoom buttons are held together with some really flimsy plastic springs (highlighted and currently covered in a drop of crazy glue). I sure hope the OM-D is constructed better than this, because I want one someday.


The part that broke off is the round black thing that’s highlighted in the image.  For reference those are about 2mm across.  The plastic springs that both locate and return the round part are towards the middle.  The spring to the right is what broke, allowing the round part to flop around under the rubber button panel.  It could have destroyed other buttons too.

In fact, every button on the back of the camera is supported by a flimsy piece of plastic. Picture all the buttons being supported inside the way parts in a plastic model kit are attached to a big plastic ring. Yeah, like that, only 1/10th the size of that.  Kinda disappointing to see this type of design/construction.  I really think this is designed to wear out and break.  This could break flopping around in a jeans pocket.

The only thing pleasant about taking this apart was discovering that the built in memory was just a microSD card in a slot.P1030050

See it there?  It’s just right of center towards the bottom with a sharpie mark on it (from the factory, not me).  There’s a plastic tab attached to the board, so that even if you take the whole board out, you’re discouraged from replacing the card.  Well, an exacto fixed that!  The card didn’t appear to have any important software on it, but it did appear to have some auto-run software that will give you a manual in your language.  Copy that to a new bigger card and you can upgrade the internal memory!  My guess is that it’ll take at least micro SDHC, which is good up to 32gb.  I wouldn’t get too excited though, because the internal memory is accessed through an internal controller, which tends to be really slow.  So it’s a good emergency thing, but of limited daily use.

Still, neat to know you can upgrade, huh?  If you want to upgrade a camera that isn’t made to last.  C’est la vie.

Oh, and yes, I did put this back together and it works fine now.  I’m good like that.