Prime Lens Focal Lengths

[samhodde]

Hi all,

Long-time reader, first time poster here looking for some advice.

I've recently started and am in the process of building up my kit of lenses, specifically primes. My big question, is there much of a difference between 24mm and 28mm lenses? what about 100mm and 105mm? I've picked out the other focal lengths I'd like to pick up. If anybody has any comparison pictures that would be awesome.

For a bit of context, I do mostly video work, with the occasional bit of still stuff when I'm shooting events. My main body is a 7D, but I'm also looking to jump up to a full frame as well in the near future.

Thanks 

[AmbientLight]

Yes and no. Although at first glance the focal lengths appear to be similar, there is a significant difference. You may eventually find yourself leaning toward shooting one of those focal lengths most of the time and then you realize the other focal length isn't so useful after all.

I've been shooting 24mm and 28mm primes since the 80s and I definitely am biased towards using 24mm much more often. Nevertheless 28mm also has its uses, so I haven't stopped using this focal length either.

On a crop body like a 7D 28mm already qualifies as a sort of "normal" lens, similar to a 50mm on full-frame, so the framing is pretty useful. Nevertheless it may be too tight for some of your uses. For example you will find it less useful for shots of groups of people. A 24mm lens will be more useful in this area.

I strongly recommend testing both focal lengths, so that you feel most comfortable with the visible frame. Then you can make your decision without having to question your decision later on.

[Hillsilly]

On a full frame camera, 24mm is noticeably wider than 28mm whereas 100mm and 105mm would appear fairly similar.  On a 7D, differences won't be quite as apparent.

There are some comparison photos for 24 vs 28mm here: -

http://en.wikipedia.org/wiki/Angle_of_view#Common_lens_angles_of_view

Just note that the comparison photos shown are for a full frame body.

[Random Orbits]

If you said that you primarily did photography, I would have suggested skipping 28mm because you can always crop, which you may not be able to do for video.  Even so, I'd suggest 24 and 35 first, and then pick up a 28 if you feel like you need something in between.

[PackLight]

As far as framing goes you would have to be 14% closer to the subject to get the same framing with a 24mm as you would a 28mm. With a 100mm you would have to be about 5% closer. Another way to think about it is this, at 24' the 24mm will have the same field of view as the 28mm at 28'.

Now if you are comparing the 100mm IS macro to the 24-105mm at 105 then there is allot of difference, not in fov but in IQ.

Same thing with the 24mm vs 28mm, it depends on which lens you are comparing. There are several 24mm lenses that wouldn't have a Canon equal at 28mm.

[symmar22]

IMO, difference between 100mm and 105mm is irrelevant, it's more about a tradition within within lens makers (Most brands take 100mm, Nikon for some reason decided for 105mm, most likely to set themselves apart).

However, 28 and 24 mm are slightly different lenses. I am so used to the 24mm that feels more "natural" than the 28mm (that's highly personnal and subjective). The difference in angle of view is not so big, so if you have room behind you, moving a couple of feet back will allow you to put as much in the frame with the 28mm.

But in the good old times of film, 28mm was a more common focal, the saying was that the 28mm is the widest angle you can use without showing excessive perspective distortion, typical of very wide angles. Fact is that the 28mm is a wide angle that gives a very natural perspective, without that "super-wide angle" look.