EF 100f/2.8 L macro question

I'm thinking of getting a EF 100f/2.8 L macro IS USM lens, because I want to shoot macro photo's. Before I plunk down my hard earned dough, I wanted to ask a question. I am going to use it on my 40D, which as you all know is a crop body. I do grasp the smaller sensor/crop vs larger sensor/FF concept. What I was wondering is, when using the 100 L lens on my 40D, I multiply the 1.6 crop factor to the 100mm lens and get 160mm. Is that desireable? When/if I get a FF body, and mount that same 100 macro L lens to it, since there will be no crop factor to apply, will I be disappointed in the focal length of my 100mm lens? Will that be a big adjustment? Is there some factor I am over looking that mitigates the loss of 60mm focal length? Something else... why do you apply the 1.6 crop factor to an EF-S lens when it was designed for crop body cameras?

Regards,

Rick

you apply the 1.6 crop factor to every lens...because lens focal length is a physical measurement...the better question in my mind is...why are you bothering to even bring in the crop factor aspect of it? does knowing that the 100mm macro on your crop resemble a 160mm lens on a FF camera help you in any way what so ever? if you have no experience with a FF camera, then i don't see the usefulness...yeah you might discover you miss the reach if you do go FF, but there's no sense in buying something that doesn't work for you now in order to get something that will work better for you IF you get a FF camera

I have the 100L, used it for about a year on the 7D (crop sensor), now using it on full-frame. Personally, I like it better on the full frame for a true 100mm focal length because it seems a bit more versatile, especially indoors. That's not to say there was anything wrong with using it on the crop sensor, it's just that you were somewhat limited to using it outdoors, or inside very spacious rooms. Set your 28-135 to 100mm and see what you think.

For use solely as a macro lens, I feel it is actually an advantage to use it on a crop sensor. Versatility improves on full frame. Image quality is absolutely stunning on both.

Dont' overlook the non L too. Most say its same quality just missing the IS and red ring.

sonofjesse wrote in post #14961916
Dont' overlook the non L too. Most say its same quality just missing the IS and red ring.

^^^True. Your next decision is how/if IS will benefit you at this focal length and for whatever you plan to use the lens for, outside of macro.

Dont worry, its brilliant on crop, i love it on my 60D.

IMAGE LINK: http://www.flickr.com …s/the_warlock/7​787070760/

DreDaze,

I think I phrased my question incorrectly, the crop factor aspect isn't going to affect my decision to get a 100 L macro lens now. The loss of reach was just something I was curious about. From the reviews and everything else I have read, I think the 100 L macro lens will benefit me now, and later, when/if I get a FF camera.

Btw, Your answers to my questions have helped me out before. Recently I made a comment about exchanging my 17-55 EF-S f/2.8 lens for a 16-35 L f/2.8 lens, which I thought would be an equivalent lens. You correctly pointed out the error in my thinking.

Thanks,

Rick

DreDaze wrote in post #14961889
you apply the 1.6 crop factor to every lens...because lens focal length is a physical measurement...the better question in my mind is...why are you bothering to even bring in the crop factor aspect of it? does knowing that the 100mm macro on your crop resemble a 160mm lens on a FF camera help you in any way what so ever? if you have no experience with a FF camera, then i don't see the usefulness...yeah you might discover you miss the reach if you do go FF, but there's no sense in buying something that doesn't work for you now in order to get something that will work better for you IF you get a FF camera

For macros, it will be very nice on a crop. The issue most people have with it on a crop is when they want to use it as a portrait lens.

Even on FF though, it still gives you a decent amount of working room and is a lot smaller and lighter than a 150mm macro (e.g. the Canon or Sigma).

For indoor macro, working room might not be an issue, however another benefit of the 100mm is that you can get more magnification with tubes than with a 150mm.

Under normal circumstances, "crop factor" can be completely ignored. There is no need even to pose the question. It is a matter of almost total irrelevance. It was coined as a way for salespeople to convince the gullible that less (a smaller sensor) is actually more (this odd thing called "reach").

This is doubly true for a macro lens. The 100L will give you 1:1 images on any EOS body, regardless of the sensor size. The difference, and this is true for all lenses, is that on a body with a smaller sensor, obviously, less of the scene is captured, that is, in comparison to a larger sensor body the image is cropped, hence "crop factor".

As you can see, crop factor does not apply to lenses at all, and most definitely, should not be applied to their focal lengths as if these in some magical way changed based on the body on which the are mounted.