I'm an amateur landscape photographer with some artistic ambition, but also obsessed with high technical image quality and large high resolution prints. So far I've worked with 35mm digital and done mosaic stitching to compensate for the lack of resolution, it works but lacks the attractive compositional on site workflow as a real view camera has. I've always kept an eye on MF digital, but when 35mm is as good as it is now (especially with the new D800 coming) entry level MF has lost its attraction in my eyes, and the attractive MF like P65+ on a tech cam is just way too expensive for my amateur budget.
So I have started to look into LF film. Film has some romance and a value by itself, but my main goal is to be able to work with a view camera and get high resolution within budget. I do realize that LF film with quality lenses and precision view camera won't be cheap either, but within reach.
But to the point - I'd like to have a digital option to complement the film. Obviously it won't be a one-shot solution, but used to stitching and shooting mostly static scenes I can live with it. I've in another thread got help with looking at scanning backs, and I've from that concluded that stitching use a large pixel MF back may be better for me. I've especially looked at 9 um pixel pitch backs with 36x48mm sensors like P25/P25+/DM22 etc, which now and then are sold used to fairly amateur-friendly prices.
I've noted that there are several "stiching backs" for 4x5" on the market (sliding back with pre-sets to quickly move the MFDB between the stiching positions), but the problem is that these are large and heavy (not intended for field use) and cover a smaller area than I want to.
My idea is to cover the full 4x5" effective film area, that is 94x120mm, which using a P25+ or corresponding means 9 images with +/- 29mm horizontal shift (58mm total) and +/- 36mm vertical shift (72mm total), and use the tech cam's native back movements for this rather than a stiching back. I'm looking at an Arca Swiss F-Metric 4x5" camera, which seems to provide a geared 100mm range vertical and 60mm range geared horizontal. By using most range for stitching movements, compositional image circle movements have to be mostly done with the front (with a 36mm offset - Arca F-line allows for rise only), but I think I can live with that.
There are a few unknowns around this:
- How bad will lens color cast be, beyond correction? I don't like ultra-wides, so 90mm Rodenstock Apo Grandagon-N is the widest I plan to go. Stitching full 4x5" area is however more than stitching backs do, so I guess it will be a rather low angle of the incoming light so I do expect to have to correct LCC inpost, but if it is so bad that most dynamic range is lost in a channel then it won't be acceptable. High DR is an important aspect to me.
- Will the analog lenses disappoint in some way I don't know about, like having gross chromatic abberations which does not show on film, or similar? I've read both that analog lenses perform well and that they perform really bad, hard to find information. Sure for 4 um pixel pitch sensors it won't be great due to resolving power limitations, but here I'm aiming at 9 um. But perhaps there's more too it than just resolving power and lens color cast?
- Will the precision in the quite large movements be adequate, depth of focus will be say 0.5mm, so with those fairly large shifts the camera must be precise enough to keep the digital back in the film plane - is it unrealistic to get that from say an Arca Swiss F-metric support and frame? I'm aiming for high resolution here, so throwing away everything due to unprecise shifting would not be good.
- Switching from ground glass (focusing) to digital back, can that be made with sufficent precision? With the focus techniques I use and near 100% large DOF photography I think I can deal with some slight focus shifts, but it must be reasonable.
Concerning lenses I'm currently aiming for Rodenstock which seems to have the focal lengths, image circles, quality and prices in the right range. 90mm Grandagon-N, 135mm Apo Sironar S (most important focal length), 180mm Apo Sironar S.
Stitching 9 frames like this will yield about 140 megapixels. To be satisfied, I'd want 100+ of these to be effective, that is not blurred by limitations in lenses.
Digital medium format really requires extreme precision to keep in the film plane etc, but one property of large format is that precision is traded with format size, that is lower precision requirements but still gain some resolution due to the much larger format. I'm hoping that those large 9um pixels (corresponding to 2800 ppi) and smaller apertures that increase depth of focus will make this feasible.
Has anyone any experience of similar setups or other valuable information?