p.1 #1 · 28mm lens recommendations for a full-spectrum mono Sony
Howdy folks,
I’m looking for some advice on 28mm lenses for a Sony that’s been converted to monochrome + full spectrum.
I know the native Sony sensors can be pretty tricky with wide-angle Leica M lenses because of the corner smearing. I’m wondering if the monochrome/full-spectrum conversion changes that at all, or if it’s still basically the same issue with the sensor stack and microlenses.
I’d especially be interested in hearing from anyone who’s actually tried Leica M 28mm lenses on a converted Sony. Do they perform any better after the conversion, or are native E-mount lenses still the safer bet?
If you’ve done a mono + full-spectrum conversion yourself, I’d also love to hear what conversion route you went with and which 28mm lens you ended up using.
Sample images would be great too, especially shots that show the corners. Thanks!
p.1 #3 · 28mm lens recommendations for a full-spectrum mono Sony
The micro-lenses are gone in the mono conversion and you'd be down to just CDAF, since the PDAF sensors require the CFA to be in place.
How well any lens performs on it depends on what they put on top of the sensor to replace the CFA and hot mirror. If it's glass that represents the same thickness as the original stack, then M lenses will still suffer field curvature issues at wider focal lengths and their corners will vignette heavier and you'll see a loss of resolution, but you don't have to deal with color cross-talk. If it's a thin stack (or absent completely like it is on my rII) then it will play very well with M lenses and film-era lenses. That will make it more prone to FC and corner issues with most e-mount lenses. How bad it is and how much you can tolerate is really up to you.
Then there's the filters, because you will need them to switch between spectrums. You can go clip in, but that is adding more thickness to your stack which will impact performance, or you can do on-lens filters (with most lenses). At minimum, you'll want a UV/IR cut or "hot mirror" filter to shoot visible light only, plus a small set of color filters to help adjust contrast and tone when necessary, and an IR filter or four of various cut-offs.
Leica-branded lenses at 28mm can be an expensive proposition. Weren't you discussing in another thread about a limited budget? If so, I'd look elsewhere. There are plenty of 28mm options among the third-parties. My Minolta MD 28/2 is a lovely little lens that typically retails for around $200.
p.1 #5 · 28mm lens recommendations for a full-spectrum mono Sony
Thanks, that’s really helpful! The Zeiss 28/2 sounds like a great option. When you say it performs well with full spectrum/IR, do you mean the corners stay sharp as well? I’m mainly trying to avoid the smearing issue I’ve heard about with the Leica M lenses
p.1 #6 · 28mm lens recommendations for a full-spectrum mono Sony
No smearing and great performance in corners but note that this is not the M mount Zeiss lenses. None of those are your friends.
This is the Canon/Nikon SLR line of Zeiss lenses. You can snag a 28/2 for around $350-550. The Nikon has aperture ring, which might be preferable. The Canon requires a chipped adapter to pass the aperture setting from camera to lens. I like the ergo better on the Canon mount but the aperture ring of the Nikon mount.
gerardrsoux wrote:
Thanks, that’s really helpful! The Zeiss 28/2 sounds like a great option. When you say it performs well with full spectrum/IR, do you mean the corners stay sharp as well? I’m mainly trying to avoid the smearing issue I’ve heard about with the Leica M lenses
p.1 #7 · 28mm lens recommendations for a full-spectrum mono Sony
How about the Contax Zeiss 28/2?
Grenache wrote:
No smearing and great performance in corners but note that this is not the M mount Zeiss lenses. None of those are your friends.
This is the Canon/Nikon SLR line of Zeiss lenses. You can snag a 28/2 for around $350-550. The Nikon has aperture ring, which might be preferable. The Canon requires a chipped adapter to pass the aperture setting from camera to lens. I like the ergo better on the Canon mount but the aperture ring of the Nikon mount.
p.1 #8 · 28mm lens recommendations for a full-spectrum mono Sony
I had a Contax 28/2.8 that was fine with IR, though I didn’t do much with it before selling it. I liked the more dramatic look from the Zeiss 28/2 better. I never had the pleasure of having a Contax 28/2.
In general, the Contax lenses I tried with IR, over the years (28/2.8, 50/1.7, 50/1.4, 85/1.4, and 100/2) all did fine WRT hot spots and retained good corners. Where they had issues were any situations with the sun anywhere in the frame. The internal reflection and flare were terrible, especially with the 50/1.4. When I used the large hood with the 85 and 100, that helped with side sun.
The ZE/ZF line has far fewer flare problems. Note that the Contax lenses generally did not have flare or reflection issues with visual spectrum/unmodified sensors . It seemed specific to IR or the sensor perhaps being more reflective and the lenses echoing that. Coatings?
