I don't need to make the DOF deeper. I just need to change the relationship of DOF to my subject.
Initially you stated you were sure that you could get the whole head into focus by tilting. I felt free to assure you that was a wrong assumption, based on my experience. What was wrong with that?
Now you are practically stating DOF is not relevant for the purpose of getting the whole head into focus. But how can it not be with a threedimensional subject? So you were talking about a piece of confetti all along? Well, granted, TS-Macro helps with confetti.
I still do not think that a forum like this is about prooving each other right or wrong by going to the book-shelf. It can also be about listening to what other people have to say. Not everybody is raising their words only to be in the center of attention. Some want to keep others from going wrong when they see it coming.
You are only discouraging people with aquired knowledge to participate here. But your muzzles are inflated and full of air.
I will never understand why anyone has to get directly personal over these topics. I have not insulted you in any way, nor am I simply interested in "being right".
You demanded I simply trust your words at face value, and preemptively flat-out stated that you were not going to back up any of your claims (which for me, personally, comes off as one of two ways...either extremely arrogant and haughty, or as an indication that the other party doesn't necessarily trust their own position), claims which were supposedly steeped in a vastly superior base of experience (how you could know that, given that you don't know anything about me, given this is the first time we've ever encountered each other, is curious.) I explained, perhaps directly but otherwise without insult, why I could not simply take you at your word like that. Simply an honest but plain and direct explanation of my stance. Your getting a whole lot more personal and insulting here, and THAT is the only thing on these forums that TRULY does no one any good. We've had far too many threads destroyed by people like you getting personal like this. I don't really care what you think of me, but there are other people on these forums who don't like threads going way off the tracks by people flinging insults back and forth.
I'm not going to exchange insults with you.
Here is another image. Maybe this will replace a thousand words and all my "hot air":
Crappy, crude, but hopefully effective example of focal plane, DOF, and a "fly head". Maybe DOF increases, slightly, as there would be a very slight wedge. But that isn't really what I'm after. I lose DOF along the bottom of the fly eye and head, but I gain a small amount at the top of the head. It doesn't have to be a lot. It can be just a couple millimeters...that's all I'd need to push the focus falloff far enough to the back of the fly's head to matter. Add in some rotation (or swing), and I could reorient the focal plane and wedge to bring more of the fly eye in focus. Since the fly's head is round, I can afford to lose some DOF at the back right area where the head turns into the mandible (it's just empty air there).
How much actual lens tilt would be necessary to get this much focal plane tilt for a subject less than a foot from my sensor? I dunno. I haven't actually engineered such a lens myself. I've found a number of T/S Macro Bellows now that claim to have 15° of tilt. Some of these products are fairly pricey, $200-300 (just for a bellows, we aren't talking about any amount of optics here), so I am at least willing to suspect that 15° of tilt is enough to be useful for subjects very close to the lens, given these things are marketed explicitly as "macro tilt and shift bellows."
Anyway, I have no interest in proving right or wrong with you. Just being clear about what I'm trying to say
. I haven't felt anyone has even understood what I'm trying to say, all I've gotten is direct counterarguments based on mistaken assumptions based on what you guys think I'm saying.
I disagree with you. You clearly disagree with me. We can exist happily in a state of disagreement without insulting each other, or demanding that either of us trust each other just on our word alone. For anonymous people on the internet, someone's word is worthless. However, at least I've tried to back up my claims with some evidence. At least I've tried to make my original point, what my ultimate goals would be if I had a specially designed TS Macro lens from Canon, clear. I believe T/S movements are beneficial for non-flat, non-product macro photography, such as insects. I don't expect to see some ridiculous improvement that would allow me to shoot at f/2.8, but maybe I can drop down to f/11 or f/16 from f/32 or f/45, and use tilt and maybe some shift to make better use of my focal plane, and envelop more of the interesting part of my subject within the DoF. I mean, that's what T/S is all about...changing your focal plane, which in turn changes what part of your subject falls within the depth of field, without moving the sensor.
I know that on my 7D, I can get pretty sharp results up to f/20 despite the fact that is a diffraction-limited aperture. Beyond f/20, the effects of diffraction (even in macro situations), really start to kick in and hurt my detail. By f/32, things are usually unacceptably soft. And, just to finish off the point. So what if I still have to shoot at f/22, even with tilt and shift? I've shot other macro subjects as narrow as f/22 before, and there is still usually a considerable amount of focus falloff. Even a small amount of tilt would be enough to MAXIMIZE the amount of my subject that is near the focal plane and within the DoF. Maximize doesn't necessarily mean entirely eliminating all focus falloff everywhere....it just means moving those points of falloff around such that more of your subject is sharp for the SAME or SIMILAR DOF. DOF doesn't have to get huge, or even larger...changing the angle of the focal plane is really all that I'd really need.