Thanks for all your work on this, Mr. AudiiDudii (rhymes with Howdy Doody?)
Yes, pretty much. It was originally the name I used for my racing team when I raced an Audi way back in the late '80s and it has stuck with me ever since.
I've been working on a related-but not quite the same rig to do close-up work with tilt on a Sony A7R2. I'm using a vintage Spiratone BellowsMaster (I am the original owner, which gives you an idea of how long I've been doing this.) I've modified it- reduced the rear attachment plate thickness and taking off all the rear movements, adding a quick release camera mount directly on the rear rail slider. This improves stability and reduces flange to sensor distance. (Wish I could find a miniature bag bellows, I'm considering an automotive rubber boot or hose section or something.)
Cool project! I love it when people customize whatever-it-is to better serve their specific needs, be a car, a camera, a piece of stereo equipment, etc.
As your know, tilts and movements are VERY persnickety in such a small format. I'm using the zoom manual focus feature on the Sony to confirm focus in the extremes, but I may try tethering to a laptop as well. This is a luxury I have in the studio that would be difficult for you on location.
Actually, it wouldn't be too difficult for me to substitute a tablet (such as a Surface Pro) for my HDMI monitor without too much of a weight penalty. The problem is finding a way to connect the two together, since the A7R, at least, doesn't tether very well.
Its wi-fi capability is very limited, too, because it will only transmit a very low-res .jpg file, which I found worthless when it comes to critically checking focus, etc.
I understand this has improved with the later models, but for other reasons, including the larger grip size, they aren't as well suited to my needs as the first-generation A7R.
You seem to have researched all this thoroughly, and to have a lot of knowledge and experience on such things. I'd appreciate any feedback or advice you have.
My experience working in the macro realm pretty much rounds to zero, so I don't have any useful advice to impart here, alas. Except maybe for the bag bellows: Have you ever thought about making one? You shouldn't need to do any sewing, because a contact-cement bond between the two layers of material should be plenty strong enough and lightproof for your purposes. If I was in your situation, I'd visit a few thrift stores and see if you can find an old raincoat or umbrella that was made with a black, rubberized fabric and source the bellows material from that. Or visit a fabric store and see what they have available for black-out fabric.
Out of curiosity, how large of an image circle do you need? FYI, Nikon also made a 28mm PC lens, too, although in my experience, both of their vintage PC lenses are only so-so performers compared to the best lenses available today.
Also, if you can deal with the Canon's electronic aperture, I understand that their 40mm pancake lens has a surprisingly large image circle and they can usually be bought for not a lot of money. Ditto for the Contax/Yashica 45mm Tessar lens, although they tend to go a bit soft at the outer edge of the image circle (or at least mine does, anyway.)
I did have a question about why you need large aperture lenses for your nighttime work- doesn't your Sony have auto-gain for the electronic viewfinder, so that you can get a bright zoomed view to focus with at any aperture? Granted, it looks grainy when the exposure is ramped up but this only effects the viewfinder image, not the exposed file (as far as I know.)
You are correct that the auto-gain only effects the viewfinder image and not the captured files. The problem I have with relying upon it is when I'm dealing with a truly dark scene, it merely makes the viewfinder image brighter and grainier, but doesn't let me to see any further into the shadows. Whereas a larger aperture
does let me see further into the shadows and, as you note, the shallower DoF that goes along with it also makes it easier for me to see exactly where the plane of focus image is located. Dealing with focus shift is sometimes a problem, but not as often as one might expect, especially one is familiar enough with the lenses to make a mental allowance for it.
Yes, I know that the limited DOF at high aperture is helpful when focusing any lens, but I would think the viewfinder focus zoom on the Sony EVF would make up for that.
The zoom does help and I use it a lot, but it also has its limitations, because the signal being fed to the built-in LCD and also to the HDMI output jack is not full-res, so I often end up iterating focus manually by tweaking it very slightly after reviewing each photo. This is also the reason why I found the Aputure VS-1 monitor's 1920x1200 resolution to be adequate, despite the existence of higher-resolution portable monitors, because the signal that is being fed is limited to 1920x1080 resolution, so there's no visible advantage to using a higher-res monitor. <sigh>
Because as you well know, wide-coverage and large aperture do not usually go together in lens design parameters. I think in large format lenses, such things were extremely rare. (Wasn't there a Schneider series that included a 150mm f/2.8 4X5 lens?)
Yes, there is/was: It was part of the Xenotar line. It was also very large and heavy and, as I recall -- I had one way back when -- a very good performer on 4x5 sheet film, but less so on 120 roll film. Today, however, they're also very expensive collector's items, so even if it was the ultimate lens (and it couldn't be, because its focal length is multiples too long for my taste on a 24x36 sensor), it's priced well outside what my modest budget allows.
