Why I win photography arguments

because I have facts on my side.

Here is a typical exchange:

Scoble: You put a 24 mm on my camera [Canon 5D] and it’s a 24mm. Put it on a [Nikon] D80, for instance, and it becomes something like a 28mm. (link)

Me: You’re smoking something. A 24mm on a D80 is still a 24mm. The FIELD OF VIEW is like a 36mm on your 5D. (link) The issue you are alluding to with wide angles being better on “full frame cameras” is related to something called retrofocal design. (link)

Scoble: …this shot wouldn’t be the same. (link TRUE). Look at that shot and see the guy to the left? He wouldn’t be there if I was using a non-full-frame sensor camera. (link FALSE)

[An explanation after the jump.]

My commentary

Here is my comment on Scoble’s photo:

London’s train station” by Robert Scoble.

The claim is that on an APS-C digital, this shot would not be “the same” (I don’t take exception) and that the man on the very left edge would not be in the frame (I prove below why this is false).

The EXIF data is missing. What lens is this?

I really doubt that can only be captured by a “full-frame.” If the lens is rectilinear you can go down to 11mm on an APS-C camera (Tamron on a Nikon, 10mm Canon on a Canon) which is a field of view equivalent of a 16mm lens on your 5D. Is this shot with the 14mm EF lens? Otherwise, I call BS on the guy not being in the frame.

Furthermore if you shot with the 10.5mm Nikkor fisheye on a D40, use Capture and hit the rectilinear button, you’d not only have the guy in the frame, he’d be 1/3 of the way in the frame!

Now if you said, “Well, for him to be in the frame, I wouldn’t have been able to handhold it, he wouldn’t be as sharp, and the noise wouldn’t have been as low,” then I’d agree, because you’d be shooting a 5D which will have a larger aperture at the same pricepoint/angle-of-view.

(No different than saying the 5D is the cheapest digital camera with a 35mm sensor.)

See, that’s penalty of a retrofocal design. You need retrofocus sooner on smaller sensors. In the Canon EF-S system, this is slightly compensated by the extra room they have in the box but only slightly. Which is why the 10-22mm and 16-55mm IS lenses are such great values. (On a personal note, I’d trade the value for the ability to mount it on a full frame camera. But that’s a personal thing—i.e. why I shoot Nikon—and I’ll accept other people feel differently.)

I don’t want to be a jerk, but the concepts here are field of view (angle of view), focal length, retrofocus, and design considerations of the reflex mirror.

See, I’m not debating you on your choice of the 5D. (I remember when you were asking for advice on twitter and the only thing I did was correct some errors on some of the things people were saying.) The reason was I felt that the 5D was the best camera for you so the general idea was correct. I thought that your preferences as an engineer, given your budget, what you like to shoot, and people you’ll be surrounded with (Hawk and others) made the 5D the obvious preference.

I’m debating on facts. Words like “focal length” mean something because they’re based on science, not preferences. That’s why I tore you apart. Every camera has compromises. I just ask that people not be oblivious to those compromises when they express their brand preferences. 😉

Parting thought

Robert Scoble : tech world :: Ken Rockwell : photography world

8 thoughts on “Why I win photography arguments

  1. Robert,

    Comparing the same lens on different bodies is a common trap. You’ll notice there is no discussion on the Canon site about vignetting, telecentricity in digital design, internal reflections in digital systems, etc. Hmm, I wonder why? Could it be because 35mm loses an insane amount of contrast on the edges (much more than the rated MTF curve would suggest) and Nikon has a patent on “nanocrystal coatings”?

    Read the article you linked and you’ll find that Canon agrees with me. In the linked article, look in the diagram. See where it says “angle of view”. Good. 😉 Now if you bothered to actually read my post, you’d realize the salient point here is:

    Angle of View != Focal Length

    Be very careful when you read the article. Canon (and me) was very careful in the use of terms such as focal length and angle of view. (All my messages were very carefully written, read my first one where I corrected your bad math even.) You were cavalier with the terminology; I was not.

    As I pointed in the mouseover text, this is a common misconception. I told you to bug your Canon friends about this, they’ll agree with me. 😉

    Thank you for playing.

    I know it sounds like nitpicking, but you see you’re an engineer, not a photographer or a scientist, that’s why. For instance, if I said it’s a 10.5mm lens is that enough? How about if I said a 10.5mm lens on a APS-C camera with a 1.5x crop factor? No because I was referring to a 10.5mm fisheye lens from Nikon which on an APS-C Nikon has a 180 degree angle of view. The 10-22mm Canon has an angle of view of only 114 degrees. For reference, the largest angle of view in rectilinear on a 35mm camera is the 12mm Voigtlander Heliar on a screw mount rangefinder with an angle of view of 121 degrees, well short of this. See?

    Furthermore, did you know angle of view changes at the same focal length based on focusing distance? These Angle of Views quoted are based on focusing at infinity. That stuff matters a lot and no serious macro photographer is going to make the mistake of confusing angle of view with focal length because of that. Here is a better article: http://www.cambridgeincolour.com/tutorials/camera-lenses.htm

    (Similarly, the focal length is measured only at infinity. This is why many zoom lenses seem to “lose reach” when you close focus.)

    Like I said, I know my shit.

    Many of our friends, excellent photographers, many of whom are much better than me, know enough not to get tangled with me on this front.

    In a larger sense, you lost this argument because I have the advantage of the null hypothesis. I state my brand bias up front and am not arguing against yours, but rather against the statements that you made that are provably false. You have to prove against the null, which is hard because your statements are littered with factual errors.

    I love Nikon, I have a Nikon bias, but I’m not a zealot. I made a choice, I live with the consequences of that choice. The one thread throughout my blog you’ll find, even when I’m in “full asshole mode” like now, is that I write in order to make others think. When you stop thinking, you get burned. Unlike others, you put a lot of thought into your camera choice (I remember I was there). But like others, you just haven’t put much thought into what you’ve said about it recently.

    Don’t feel so bad. This happens all the time in San Francisco because there is a huge Canon bias up here due to a founder effect caused by many great Canon photographers who intersect the tech world (Lane Hartwell, Scott Beale, Jim Goldstein, Thomas Hawk…). This causes people to parrot their choice in camera brand without understanding the thought that went into it. Heck, at Sanford’s Christmas party, one guy was practically in tears with his final argument summed up as, “You must be wrong because my wife makes over $15k/wedding.”

    Haha. Shit. Gary Fong claims to make 10x as much and he’s still a nut job.

    Never understood bridezilla. Never will. Just deal.

    But the facts are these… I’m right, you’re wrong, and Canon’s own website agrees with me. 😉

  2. By the way, I am well aware that with the same lens on a APS-C camera the guy wouldn’t be in the shot. But I carefully read your comment which was he wouldn’t be in the shot if you were “carrying a non-full-frame-sensor camera”.

    The issue I’m takings that you wouldn’t have the same lens on if you had an APS-C camera, you’d have a different lens. Making such a “same lens” comparison is deceptive marketing practice and you fell into that trap. (That’s common, many Canon photographers make a conscious choice to avoid the excellent EF-S lenses because they plan on upgrading to a full frame camera later. I pointed this out many times in earlier articles.)

    My favorite lens is the 12-24mm f/4 DX Nikkor. If I was shooting a D3, it’d be the 14-24mm f/2.8 FX. In fact, find me in two months and I’ll prove it to you. 😀

    How come the kit lens on the Digital Rebel is the 18-55mm, but the kit lens on the film Rebel is the 28-70mm? Makes you… what’s the word for it… think? 😉

  3. Let’s state for the record how you got in this shitstorm.

    Your advice was right (the original twitterer should probably switch to a Canon 5D, or better yet, wait until the 5D Mk II in February), but your reasoning was wrong (you should have never compared the 5D to the D3 and neither should he have).

    (Yes, people around here may joke that I’m better at identifying people based on camera choice and lens preferences than by their actual names.)

    The correct reasoning is, if you have to ask the difference between two very expensive cameras, then you’re better off with the simpler/cheaper one. Do you realize how hard it’ll be for this person to figure out a camera with no scene modes and three extra BANKS of buttons on it? It’d be like giving a Stradivarius to a first time violinist…only worse because a Strad still plays like a violin, a “pro”-style camera (D300, D3, 1D Mk III, 1Ds Mk III…) is set up very different than his D70.

    I started by pointing out that the comparison you made (Canon 5D vs Nikon D3 on cost alone as a definition of value) is rather unfortunate. (You’ll have a hard time getting any photographer you respect to gainsay me—shall we call Thomas Hawk, Jim Goldstein, Lane Hartwell, or Scott Beale—they all shoot Canon, what do you think they’ll say?) I then corrected your misstatement about the success of the 5D—during the last years the 5D has been out, Nikon has been gaining far more marketshare than Canon. Then you got all defensive and started to spout “full frame religion” on me and the entire twitterverse.

    I let it all your opinions slide except for the obviously false statements which I pointed out as they came up.

    You say I’m pedantic

    Definition of pedantic: marked by a narrow focus on or display of learning especially its trivial aspects.

    What I said (above) before you used that pathetic, unfortunate, and dismissive adjective: “I know it sounds like nitpicking, but you see you’re an engineer, not a photographer or a scientist, that’s why.”

    I don’t think I was being “pedantic,” I felt I was just valuing the truth and letting you voice your opinion.

    You know what’s pedantic? Demanding a deliberately deceptive “test” of claiming that we have to use the “same lens” when comparing a shot. Who the hell shoots the same lens when using a totally different camera design?

    I shoot the shot, not the lens. Shooting the lens is…PEDANTIC, get it?

    Let’s take any Canon photographer we both respect and ask them what lens they’d choose on a Canon 40D to get the shot you pointed out. Let’s see how many of them would come back and say, “No, it’d be impossible to get that guy in the frame with a 40D.”

    Maybe you should get off your full-frame high horse and do the same.

    Many of these people carry a Canon 5D for a reason—that reason centers around the sensor, but not for the reason you state; not for the photograph you showed (cloudy day, extremely well lit indoor/outdoor shot, wide angle but not ultrawide, standing height, probably handheld).

    Moving targets

    You’re being a moving target when you claim now that the test is the SAME LENS on a DIFFERENT CAMERA. That was not your original claim. Your original claims were:

    1) The 24mm lens “magically” changes focal length when put on a different camera. (I proved that statement to be false: it doesn’t, it changes field of view. I further educated you on why those terms need to be separated and I corrected some of your bad math in your FOV calculation.)

    2) That one cannot get the guy in the frame with an APS-C camera. A claim that also was provably false. (I noticed you still haven’t said what focal length that was shot at.)

    3) That Canon’s literature agrees with your claim (1). Easily tested and proven wrong. (I hyperlinked the wikipedia definitions of Focal Length and Field of View. You can look up Angle of View which directs you to Field of View.)

    The absurd thing is I have the advantage of the null hypothesis. You, my dear pundit, by making silly claims, have the burden of proof. And then when you’re shown up, you change the criteria. That’s the defintion of a “religious zealot”—it doesn’t matter if the religion is Canon, Nikon, Mac, or Microsoft.

    The psychology of pundistry

    Take a step back, I never took issue with your choice in camera. I don’t deny that full frame had advantages (it has disadvantages also, particular in the areas of cost, size and weight). I stated my bias up front and to everyone. Shit, half of San Francisco knows I shoot Nikon (and Leica).

    You know full well that I never took issue with the fact that a larger sensor has less noise, nor that you cannot get the same exact shot with a different camera, nor that the 5D is the only sub-$3000 camera with a 35mm sensor. (In an article linked above, I all but told people to buy a 5D last year if they wanted a “full frame” sensor.) I don’t like to engage in an argument I’d lose.

    The thing is, I know you’re smarter than this, and I have to conclude that you’re just really pissed off I schooled you and only took you to task on the provably wrong statements you made.

    What you don’t gather is the reason why that happened. Mouse over the “Ken Rockwell” in the original article. The reason is because I like and respect you. I’d never bother to pick a fight with your opinion (even when I disagree), but I will pick a fight with your falsehoods.

    “Onward.” (I hate these sort of dismissive platitudes. When is a discussion ever over? When do we ever turn our brains off? When we have lost.)

  4. *grabs popcorn*

    This could get good…

    Mr. Scoble, you’ll get an A for persistence, but so far a D- for being correct, personally I think Godwin’s Law may be your only out at this juncture…

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