Saturday, February 19, 2011

Tricks of the Camera

I had three lenses with me in the camera bag yesterday, so I thought it would be neat to illustrate how different lenses affect the way a bicycle looks in pictures. Here are three photos of my mixte standing in the same position, taken with (left to right:) an 85mm lens, a 50mm lens, and a 35mm lens, using identical camera settings. Notice any differences?

Here is a closer look at the picture taken with the 85mm lens. First off, notice the relationship of the bicycle to the trees: In this picture the bike looks like it is positioned in between the trees. There are hardly any trees in the frame itself and if I wanted to I could crop them out all together, making the bike an isolated object in the midst of snow and sand. There is also not a great deal of background information in the space above the bike: a few stairs, but that is all. Furthermore, the things in the background are kind of blurry in comparison to how sharp the bicycle itself looks. And finally, take a look at the size of the bicycle's wheels. The bike is slightly turned toward the camera and the front wheel is closer to me than the rear. But despite this, the front wheel does not look much larger than the rear; the bicycle looks proportional. The 85mm lens is considered a "portrait lens" precisely because it creates these effects: It isolates the subject from the clutter of surrounding objects and reduces unflattering foreshortening effects in the subject's face and body.

Now the same scene, but taken with a 50mm lens. Notice how much more background information is visible in this picture. And it's impossible to crop out, because all that extra stuff is directly behind the bike, rather than around it. The same trees that were spread out to the right and left in the previous picture, now overlap with the bike's wheels and can't be cropped out. More stuff in the space above the bike is visible as well - now we see not just the stairs, but a winding path. And the background scenery is in sharper focus than in the previous picture. It's a nice composition as far as narrative goes (we get more of a sense of the bicycle being in the woods), but a portrait or product photographer would tell you that the background is starting to compete with the subject of the photo. One of the trees looks like it's growing out of the pannier, and the winding path draws the eye away from the forms of the bike itself.

And same scene once again, but with a 35mm lens. The entire patch of woods and the street behind it have now been wrangled into the shot. The background scenery is just as sharp as the bicycle itself, and there's so much of it, that the scene looks altogether cluttered. Also, notice that the front wheel of the bicycle looks considerably larger than the rear, as a result of being closer to the camera. Foreshortening effects are pretty strong with this lens: If I were photographing a person's face, their nose would appear exaggeratedly large in comparison to their eyes for the same reason as the mixte's wheels look to be different sizes.

There is much more to be said about differences between these lenses, and in fact I haven't given a proper introduction to camera lenses at all - but that would take ages and it's nothing you can't find in an online reference. Hopefully, these pictures illustrate the way in which lenses play a role in bicycle photography, and why sometimes it seems like you just can't compose the shot you want with your camera. For those of you who use digital SLRs with interchangeable lenses, which do you prefer to use for bicycle photos?

25 comments:

  1. Beautifully illustrated and articulated! I wish you would say more on this subject but I appreciate the time it takes to do it properly. Perhaps others could post links to favorite sources in the comments?

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  2. i love me a good portrait lens (70-200-holla!) but i use my fast 35 for portraits all the time, too...guess i'm a rule breaker. :-D

    if the lens was fast enough, you'd get more subject isolation with a fast wide prime, too, but it would also obviously depend on your position relative to the subject, too.

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  3. Fascinating. I have only a 35 mm lens for my Nikon SLR and in the past I used a 50 mm for my Nikon DSLR. Those are equivalent, right, without a full frame sensor on the DSLR? At this stage, I like shooting with only one lens, for learning purposes and so I become more "one" with my camera.

    But now I want an 85 mm lens. Which would be a 50 mm for a film camera, is that right? I'm not totally sure how that works. I love how that first photo isolates the bike and puts it all in proportion.

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  4. Nice post!

    I shoot Nikon, and aside from my everyday zoom, I am a huge fan of prime lenses. Coincidentally I have a beautiful japanese 85mm Nikon and a 50mm.

    I do find the 50mm more versatile, but adore my 85mm. Must admit though, have not used for bicycle photos as yet, but you have inspired me

    (the 85mm is the classic lens for taking "street photography" - ie - candid, marketstall type stuff)

    Baz
    http://gotaukulele.blogspot.com/

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  5. I prefer my trusty 50mm f1.2 ... however, with some camera bodies one must factor in a 1.5 magnification, thus rendering the lens with an "effective" focal length equivalent to somewhere around a 70-ish mm lens. That's (almost) like having a very fast portrait lens. Still, though, I tend to prefer the "normal" qualities of the 50 mounted on a full frame DSLR, when it comes right down to it.

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  6. Sorry, but with the investment in camera equipment I made for film digital is nowhere on the horizon for me. Besides, I still like film.

    That said, your basic question is very relevant to the younger digital photographers of today. IMO digital makes it to easy to become a snapshot artist anyway.

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  7. Putting Constance to good use! One note for folks using a DSLR is that most of them have a 1.6 multiplier due to the sensor being closer to the lens. So a 50mm lens is the equivelant of an 80mm lens. This lets you do some portraiture for less $$$ upfront, as 50mm standards are plentiful and inexpensive. An 85mm has a 135mm equivalency and so on.

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  8. For Dottie...If your Nikon isn't a full frame sensor (DX) than you generally multiply the film lens by 1.5 That will give you the rough focal length.

    So your 50mm film lens will be approx 75mm on your Nikon DSLR. 50 x 1.5 = 75

    You multiply it by 1.5 cause the Nikon DX sensor is approx 1.5x smaller than 35mm film.

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  9. I actually use a 35mm or 50mm lens on my dSLR for casual photos most of the time, simply because the camera is more compact with them and easier to carry around. So the 85mm lens only comes out when I am out photographing with a purpose - it's heavy and huge, especially with the hood on.

    Walt - I dislike digital image capture, and we use only film for "real" (art) photography. We use mostly medium format, and our main setup is a Hasselblad 500CM with a bunch of lenses. We develop B&W ourselves, and give the colour film to our local pro lab. But for commercial photography, it's unrealistic and impractical to use film today, so we now have a digital set-up as well. It would also be unrealistic for me to use film for the blog, as it would take too much time and money.

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  10. So, a bit of lens info. Only read if you are curious about this stuff.

    It's important to note that while digital crop-factor bodies make a 50mm lens seem like a 70mm lens, they in fact do not give you the perspective and subject flattening of a real 70mm lens, they simply take a 50mm lens and crop its useful area. So, yes, things are closer, but you could do that by using a 50mm on film (or full-frame digital) and only using the centre portion of your frame.

    Now, what about a 35mm lens? Well, it's the same idea. If you take a 35mm lens, the digital crop factor makes it "see" approximately the same amount of stuff as a 50mm sees on ye olde 35mm film. But it does not give you the perspective of a 50mm, you still have a cropped wide angle look. Many people use a 35mm on digital crop-factor bodies because a 50mm would be too close, it would make you have to step back a lot, but it does not give you quite the same image in terms of perspective. Depth of field is also dependent on the lens and aperture and does not change if you crop your "negative size." This last issue is a bit of an advanced topic and is best looked up on photography sites, I can't adequately cover it here.

    All three pictures here are taken on a Nikon DX-size body, so they are all cropped to a factor of 1.5. If we put these lenses on a 35mm film camera, and stood in the same spot the subjects would look exactly the same, except there would be MORE background around them. Same with putting these lenses on a full-frame digital body.

    So, it's very important to distinguish between the crop factor, which does not affect how your pictures look and only crops them, and the lens focal length which does affect how the pictures look.

    The crop factor is not new to the digital age, by the way. Medium format cameras (have a larger negative and) use an 80mm lens instead of a 50mm as their standard lens. So, with 80mm, they get roughly the same amount of stuff in as a 35mm film body does with a 50mm lens, but the medium format picture will have the perspective of an 80mm lens. So if you grew up with medium format lenses as a "standard" instead of 35mm lenses, the digital crop factor for you is not 1.5 but more like 2.3.

    To sum this all up, how much stuff a particular lens gets into your picture depends on your "negative" size. That's why compact/pocket cameras with their pinky fingernail size sensors use focal lengths like 10mm. And that's also why EVERYTHING is in focus with those lenses. They are really really wide and the rule is the wider the lens, the more stuff is in focus. That's why you can never isolate stuff as well with a pocket camera as you can with a DSLR with its larger negative size. Does that make sense?

    Anyways, fun stuff.

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  11. wow! that's very helpful and now I want to lug around lenses again. We have two but I can't remember where the non 35mm is. ( it's B's so I don't even know which it is. I kinda miss my film camera- I've lost so much photography info over the past 12 years it's sad. I used to develop my own prints for fun and paid attention to settings etc. Now I use my iphone. blah.

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  12. pilypas - The quick introduction, is that camera lenses range from "wide angle" (low #s, usually <50mm) to "telephoto" (high #s, usually >80mm). The more wide angle a lens is, the more stuff fits into the picture, creating foreshortening effects. The more telephoto a lens is, the less stuff fits into the picture, creating flattening effects. The best lens for portraits (and pictures of isolated objects) is somewhere in the middle, but closer to telephoto, with an 85mm being just about perfect. Just look up "telephoto vs wide angle" or similar wording and you'll find plenty of detailed explanations. I do not know of any specific online tutorials.

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  13. Velouria said...
    "But for commercial photography, it's unrealistic and impractical to use film today, so we now have a digital set-up as well. It would also be unrealistic for me to use film for the blog, as it would take too much time and money."

    Sigh! :( Ain't it the truth.......

    Think I'm gonna go pet my twin lens to keep it from getting lonely! :))

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  14. correction before someone else corrects me : )

    It would probably be more typical to say that <35mm is wide angle and >60mm is telephoto

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  15. Here is the classic tutorial on perspective that has some interesting examples of facial distortion:

    http://stepheneastwood.com/tutorials/Tutorials_Lens_Perspective.htm

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  16. This page has an especially informative comparison.

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  17. I normally use my 85 mm for bicycle work, but I'll use
    the 50 in a pinch and adjust for depth of field with
    exposure and f/stop.

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  18. i love your blog... i can learn so much

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  19. Whether a 50mm lens acts like a 50 mm lens or a 75mm lens depends on the size of the sensor in the camera. Nikon makes DSLRs with full-sized sensors (so a 50mm lens acts like one) and with smaller sensors (which causes the telephoto effect). There's a good, concise, admittedly Nikon-centric explanation on the Nikon website:

    http://www.nikonusa.com/Learn-And-Explore/Nikon-Camera-Technology/g588ouey/1/The-DX-and-FX-Formats.html

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  20. What lens I use really depends on what part of the bike I am shooting, what kind of effect I want to get, the setting I am shooting in, etc. It also depends which camera I am shooting, as I have different lenses for different bodies. If I am shooting digital, I use my Pentax K-x and my go-to lens is a manual 50mm f1.7. If I want to isolate the object, I just shoot with a fast aperture and blur everything out of the background. If I am in a confined situation, I pull out the kit lens, an 18-55 zoom, and use that. I don't love the kit lens, as you can't blur the background out as well, and the images come out noticeably fuzzier than with the super sharp 50mm prime. One big advantage to the kit lens is that you can focus much closer than you can with my 50mm. Since I don't have any macro equipment, this lens helps me get very close to things if I want to do a detail shot or shoot a small flower or whatever.

    When I shoot film, I usually use my Olympus OM10. My favorite lens for that camera is a Tamron 100mm tele-macro. This thing rules. You can get very close to things, and it also magnifies, since it is 100mm focal length. It goes up to f36, so you can usually get enough DoF. I love this lens for abstracts when I want to get nice and close to an interesting texture or pattern. But even with this great 100mm lens, I usually go for the 50mm f1.8. It is not as good as the Pentax, but still a good lens.

    So anyway, for my general whatever photography, I have to say that 50mm is my favorite, but this article definitely is making the gears in my head start to spin. I am going to have to try some different things! I am going to be starting medium and large format photography for a class I am taking, so I will also get to see what effect that has on my pictures.

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  21. I definitely like a 50mm lens on my film cameras for these kinds of shots, or my 70-210mm lens at 70mm works pretty well also. I've noticed a lot of the things you mentioned, but I hadn't thought about some of the other issues with cropped digital sensors and conversions - the perspective issues and whatnot. One more thing I'm happy to do without.

    With the 50mm (film), I also feel like I can pretty easily either shoot the whole bike, or close up shots of bits of it, and have a wide range of depth of field options as well, so it's really versatile for doing portraiture. With my 28mm, I'd have to be right in front of the bike just to make the bike take up most of the frame, and my fixed 200mm i'd have to be a block away :)

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  22. Regardless of the focal length of the lense, that's one handsome bike, Velouria.
    Alan at Eco Velo has some very helpful tips regarding bike photography.
    http://www.ecovelo.info/2010/12/30/testing-testing/

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  23. That bike will look great no matter how you photograph it!

    I don't have a camera with multiple lenses. I once learned how to use SLRs, back in the days before digital photography, but have never been a serious photographer. But I find the post interesting because it illustrates what artists think about, including proportion, perspective, line and color.

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  24. Great examples! I've become lazy and pretty much keep the kit lens on (18-55, I think). Partly out of laziness, partly b/c I wouldn't be heartbroken if it was damaged. ;) For component shots shots I turn to the 50mm. I love how it pushes out all the background. My husband has fallen for his 17-85, which lives on his DSLR now.

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