DOF: comparing TS-E lenses for Product Photography (1" - 10" sized jewelry)

[mr.peacock]

I'm new to jewelry photography, and using a 7D with 100mm Macro L.  It's awesome, but DOF is pretty extreme for my subjects (imagine a bunch of paperclips bent into polygons that interlock to form cube-like structures approx. .75" high and up to 10" in length). So I'm looking for debating to get one of the 3 canon TS-Es.  Looking for some information/guidance about how focal length impact the tilt/shift effects of the 24mm, 45mm, and 90mm lenses, especially with regard to DOF, but also in terms of creating some drama/intrigue to the image.

I recently counter-tested the new 24mm TS-E II L on an 8" diameter necklace and loved it.  I know, it's an architecture lens so what I'm doing with it, right?  Well, I've heard so many good things about the quality of this lens, and love the option of independently rotating both tilt and shift.  The result surprised me: When I shifted up and tilted down I got an amazing DOF and it was dramatic looking, yet very natural (shifting counteracted distortion and the image had life-like proportionality and dimension).  I've also tested the 90mm, which seems to work well, but I didn't notice the shift or tilt making as much of an impact on the subject's "presence", and it didn't seem as sharp.  So I'm leaning toward the 24mm, despite the fact that no one seems to suggest this focal length for small objects.  And now, back to my original question: how does focal length impact the tilt/shift effect, especially with regard to DOF, but also in terms of creating some drama/intrigue to objects 1" - 10"?

[Bob Atkins]

Technically TS lenses have exactly the same DOF as regular lenses, it's just that you can tilt the plane of focus so you can extend the apparent zone of sharpness to match the subject. Shift doesn't really affect DOF.

In general I think the shorter focal length lenses can give a more dramatic effect. The longer focal length lenses (like the 90mm) are more suited to semi-macro product photography, while the wideangles are more suited for landscape and architecture. The 90mm will produce less distortion when used for product work and will include less background than the 24mm will, which is why it's popular for commercial product work.

It's worth noting that the T/S lenses all have recessed rear elements and so the Canon TCs can be attached. Canon don't advertise this fact much, but quite a few people report decent results and it does give you some control over the focal length. Not sure if it limits the extent of tilt and/or shift.

Of course you can use pretty much any lens for any purpose, so if you like the way shots taken with the 24mm look, then that's the one to get!

[mr.peacock]

Thanks.  I've read most of what you've written on your excellent website regarding tilt/shift lenses & DOF.  Thank you for reiterating what that we are really talking about is the focal plane.

The question still stands: Does focal length impact the tilt or shift effect?  I read a post somewhere (don't remember or I'd ask that person) that said the longer the focal length, the more tilt you need in order to manipulate the plane of focus.  Why is that? (Or is it even true)?

I will be testing the TS-E lenses with lighting soon and will post results so we have a real basis to talk about this stuff.

thanks