Flat Field Photography

[dalewagner]

I've just purchased a new Digital XT and have yet to finalize a decision on a lens.

Here's my question: I'm an architect and intend to use the camera (in part) to copy my drawings for eventual inclusion in my portfolio. Typically these drawings are freehand ink and marker sketches on yellow tracing paper. Sometimes, other medias and sometimes hardline (drafted) images. The drawings are often usually 12x 18" to 18x 24".

I used to reproduce these images with an F-1 using an architectural screen, and a FD 50 3.5 macro. It is always essential to get the linework perpendicular and parallel. The architectural screen was fabulous.

So now I finally get to the question: How can I get a grid in my XT viewfinder? And if not there, where? And how "flat" is the macro setting on the 28-135 IS USM? Must I buy another macro, i.e. 100, or will anything else suffice?

Thanks for the help.

[chtgrubbs]

I am afraid the does not have interchangeable screens. You might find a repair shop that could modify and install a grid screen for you. Your zoom lens is not flat field, although at small apertures lilke f/11 or 16 it shouldn't be too much of a problem. But it will have barrel or pincushion distortion. This can be corrected with software, but by far the best decision is to go ahead and get a macro lens or at least the 50/1.8 lens. If you are working on a copy stand the focal length multiplier effect of the digital sensor will mean that only smaller can be used. Larger pieces will have to be done with a tripod.

[wilflee]

Since you already have an established and proven process with the F-1, why not just get a film scanner instead of new body/lens? A scanner introduces the least amount of change to your proven process. Whereas a new camera/lens/workflow basically upsets the entire process.

[Todd Jacobsen]

Seems kind of "backward" to be using a camera to copy architecture drawings. Isn't that the purpose behind scanners?

[JBillings]

Can't help with the interchangeable screens, and that's a real shame. I miss my F-1 for that reason, and only that reason. I'm much happier with the 20D, and instant feedback. The 28-135 probably isn't all that "flat". You can compensate for the depth of field curve by stopping the lens down. You might consider getting a copystand so you can assure yourself that the camera is parallel to your work. An angle finder is a nice accessory too.

[rent]

i think scanners that can work with the size of dale's drawings are probably prohibitively expensive.Seems kind of "backward" to be using a camera to copy architecture drawings. Isn't that the purpose behind scanners?

sorry, i don't know much about flat field reproducing though. :confused:

-alex

[ScottE]

The 28-135 is not really a macro lens so it is not designed to focus on a flat field. That is one of the characteristics of a real macro lens. A 50/2.8 macro lens by Canon or Sigma is still your best bet for a flat field lens.

Scott