Canon 100mm f2.8 Macro Vs Canon 24-70mm f2.8 L

[netronelson]

Hi There,

I am in the process of making a childrens picture book, and i'm making 4 / 5 inch models which I will pose and photograph as my 'illustration'...

I've waited a long time to get to the actual photography bit, but now i'm surprised my 100mm macro doesn't seem to give as good results at the 24-70 L - is this right?

Depth of field is the problem - i'm having to shoot at f20 / f22 to get the whole model in focus, here's an example of the model:

but to get the right depth of field I must move the camera back, but can't since the room isn't big enough...

Is there something else I can do? any other thoughts / suggestions?

Thanks,

Nelson.

(note - I've 2 cont lights @ 5k, and a light table underneath for the photography, tripod, remote shooting on a PC, etc...)

 

[vaizki]

If that's a 1/2 inch grid on the surface there, does look like a bit too large of a subject to be shooting with the 100mm macro indoors. It's a great lens but you're better off with the 24-70..

Check out the calculator here for DoF:
http://www.dofmaster.com/dofjs.html

If you want to get really involved in DoF management here, consider a 45mm or 90mm TS-E tilt-shift lens. There's a steep learning curve and price though

Also good to note that if you are focusing for example on that NOSE there, you're using only half the DoF (from focus point onwards).. so focus on the chest for example.

 

[netronelson]

aha - perfect. and they even make that app for the iPhone.

Cheers,

Nelson.

 

[I-S]

This sounds like a job for the venerable 50 F2.5 macro. You don't seem to need 1:1 for this application, and the 50 macro is very free from distortion and a good lens - just a rather unexciting one. Alternatively, you might want to try an extension tube on your 50 F1.8.

 

[tdodd]

For the same framing of the subject your DOF will not change whether you shoot at 100mm, 70mm, 50mm or anything else, for the same aperture value.

Consult the tables for....

100mm lens at 100cm and f/16;
70mm lens at 70cm and f/16;
50mm lens at 50cm and f/16.

Obviously the shorter the lens you use the closer you need to get to the subject in order to maintain its size within the frame. The DOF is the same for all combinations. What you gain in DOF with the shorter lens you lose again due to the shorter subject distance needed to compensate. Swapping to a different focal length may help with your working distance and FOV, but not with your DOF.