Craig, looking at the end-to-end "system" of lens, CCD, and software, Troy can easily crop out 60% of the pixels and still have as many to play with as in the 16 million in a 1DsII image... and still have a better image because of better software.
You'll have to prove that, Dan. The number is about 57%, and I'm not going to take your word that Troy's software is better or that his residual image is better. One thing that is inarguable is that, once Troy crops out 60% of his pixels, his enlargement capability is similar to a 1Ds2.
You shoot Canon CCD-RAW: Which software do you use for your conversion? Canon? CaptureOne? ACR? If you use ACR, do you correct for chromatic aberrations, vignetting, & barrel/pincushion distortion?
No, I don't shoot Canon, Dan, but I have in the past. Yes, I do correct for CA and vignetting and I do so manually so that the port is considered. Barrel/pincushion is not important enough underwater to be concerned with. I have corrected for that before using PS plugins, however.
Troy's software is already configured with lens data to clean up any CA, as part of the "system" he has. Granted, DxO Optics Pro now does this too; but I would still have to see the results.
No, it isn't, because Troy's software doesn't know about the ports which introduce far more aberrations than his lenses do.
Also, the number of pixels a camera can deliver is overrated, when it comes to digital photo prints (as opposed to inkjet).
Tell that to the one's here boasting of 5'x8' print capability!
Closely related is If I make a mural size print, can I trade off any quality since the viewing distance will be greater?
Yes, and that tradeoff can be made for 35mm solutions as well.
All this is irrelevant, Dan, as your points typically are. There is a difference between an H3D and a 1Ds2 or 1Ds3. It is the relative difference that is important here. I've noticed no one has dared take on my assertion that a 1Ds2 is capable of 3'x5' prints if the H3D can do 5'x8'. Why the constant double standards?
Now, getting back to Troy's Hassy and it producing quality large prints, his shooting style for macro will be different than your 1DsII: Whereas you want to "fill the frame" he can simply "zoom by cropping," having the ability to lop off 60% of the pixels and still have the same number as your Canon has.
Not if he wants to preserve his IQ and print size advantages he can't. Furthermore, cropping in the manner you suggest gets Troy about a 35mm frame width. A 1Ds2 can easily do better than that (it starts out there with every lens!) and the difference is quite valuable.
[Granted, Troy would not be able to stop down as much -- Probably no more than f/16 -- if he intends to zoom by cropping without starting to see diffraction artifacts, as you correctly pointed out previously, since the circle of confusion would be smaller. That being said, the because he would then only be using a portion of the lens coverage real estate (off axis distance), this is balanced by greater corner sharpness due to cropping out the areas where the MTF curves fall off.]
Yes, Dan, Troy would in essence be converting his MF rig into a 35mm one without any IQ benefits, without any print size benefits, without any high ISO benefits, and with only a 120mm macro lens option that offers only f/4 for focus and no 1.4x teleconverter. Sounds like a loser to me. You are always so eager to discard all the benefits of MF when arguing that macro isn't so bad, then turn around and extoll the virtues of MF image quality ignoring the fact that you've discarded it.
...And, if you like telephoto compression of the scene, you get more of that with medium format due to the longer focal lengths for the larger CCD/film area for MF. But, that is a topic for another day, as it's almost midnight.
No you don't, Dan. The 120mm has a 70mm equivalent perspective by Troy's own data. My regular macro lens offers 180mm and I use it currently on a DX crop. 35mm can easily provide 300mm or even 400mm of macro perspective while maintaining excellent quality. You are totally wrong on this one.