Steve Spencer
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 p.2 #15 · First Sighting: A7rii Thin filter in action | |
uhoh7 wrote:
I think we have two subjects here:
1) how is the very reliable v2 Kolari mod looking on A7r2? Frankly I see little testing of interesting lenses so far. Digilloyd showed the SEM18 as great, at 240 level basically, but that lens is extremely friendly to the v2 mod, as Jim Kasson showed. Rich brings up a really good point, is there less colorshift with A7r2, "smearing" aside?
We need to see the v2 (which is what Kolari is using at the moment for thin-filter) on a bunch of other M/LTM wides to really see how it compares to A7ii and other A7 flavors. But I expect it's very much similar to A7ii. Way better than stock, but M240 is still well ahead with many lenses, like the ZM35/2.
2)Much more mouth-watering: better mods.
llija has been loving this discussion and is very open to new ways of modding the A7r2. He is now looking at a very thin filter for the LPF2 possibly as thin as .2mm yet still with functional IR cut.
Sam has shown the Taiwan Master's completely different alternative to the LPF2 method, actually removing the base coverglass which is glued to the sensor. Sam is very positive about the results, and believes if you do this, that 1mm in the LPF2 is fine, and with the right glass WB is really no problem. The Taiwan Master has done this to probably 10 different A7 cameras, of various kinds. Its a completely different way to get the evil glass out of the path for our sweet film lenses. It's entirely possible that this is already equal to M240 or better with all M/LTM lenses. His shots with that 21/4.5: really something.
llija has himself removed the base coverglass on sensors. Besides it usually being more risky to the sensor (perhaps there are multiple ways to do this) what he noticed was dust could be a real issue, tiny particles which get on the sensor during the removal of the glass, or perhaps might find their way there later. So I've asked Sam Lee to do some shots of the sky at F/22 or F/16 to see if anything can be seen. And I asked: once you put LPF2 back over the sensor (now without glass) is it a tight seal? Could dust get there later, and either way what's the best method, if there is one to clean a bare sensor?
As far as level of interest in a A7r2 mod, I believe if an option that hits the M240 benchmark or exceeds it becomes available---not just with a few lenses but across the board---there is going to be plenty of interest, regardless of the new Sony UWA natives. Many people all around the world love RF lenses, for character, history, size and performance. A practical mod to make the Sony BSI 42mp really shoot them like the M9 will be quite interesting.
If Zeiss or Sony understood the marketing potential of the deep film/ALT/RF culture they would simply do a production run of a few hundred A7r2s with an ultra thin cover of some sort, sensor moved forward accordingly and updated firmware to let a user tune the processor to lenses, and allow easy switching and see what happens. They would be heros to a very influential group of photographers and collectors-who BTW made the NEX-5 famous much faster than would have otherwise been the case. Would not cost them much. Put a nice paint job on the r2 and call it a Ikon or Hexar--instant multi millions in free advertising for them. A techart style adapter really well done with eye-AF working well--how hard would that be for Sony or Zeiss? But I can't hold my breath till common sense and power of tradition dawns on corporate committees: life is short, and alternatives are increasing, thanks to great folks like llija and the Taiwan Master  ...Show more →
I know personally, I would never feel comfortable with taking off that epoxied cover glass. I would worry about dust on that open sensor that would be permanent and ruin the camera.What we don't know is the long-term viability of such a camera. Will it last five years? Three? Two? What happens if you take it to the dessert?
I think there is another issue as well. I don't think we can treat all RF lenses as the same. It is clear that Leica and even Zeiss with the ZM 35 f/1.4 are designing lenses with the cover glass in mind. So if you consider a lens like the Leica M 28 f/1.4 ASPH which Sean Reid finds does better on the Leica SL than the Leica M240, then we can't expect a lens like that to do best on a camera with the thinnest sensor stack possible. I have that lens and it really does quite well on an unmodified A7rII. I think it may well lose performance if you make the mod have thinner glass.
Another issue that has just been raised is whether front end filters can be used as alternative to modifying the sensor cover glass. There is an active thread on the first page of the alt forum with some quite promising results will all kinds of lenses using this approach. Including great results from the Contax G 21mm f/2.8--not a lens i would have expected to be easy to adapt for better performance. There is also very positive results for the ZM 35 f/1.4 with this approach and I will probably modify mine in this way, and the beauty is the modification can be reversed simply by unscrewing the filter on the front of the lens.
I hope that Ilja in the future can offer mods with different cover glass. I can see someone who only shoots film lenses wanting a camera with the LPF1 at about .5mm and the LPF2 at about .2mm (and maybe even the epoxied cover glass on the sensor removed--but again I would have to know that isn't going to ruin my camera in a year or less if I went to the dessert). I do think as thin a filter as possible makes sense with a lens designed for film.
I can see a very different approach, however, if you want to use the modern Leica M lenses designed for digital. These lenses probably include the SEM 18, the WATE, the SEM 21, the 21 lux, the 24 Elmar ASPH, the 24 lux, the 28 lux, the newest 28 cron, the newest 28 elmarit, the 35 Lux ASPH FLE, the newest 35 cron, the 50 Noctilux f/.095, the 50 AA, probably the 50 f/1.4 ASPH, and the 75 AA. For these lenses I would want a slightly thicker cover glass probably just like the current Kolari v2.
I would even like to see a different version that would strike a balance between the modern Leica lenses and the native Sony lenses. I think there is a substantial group of people that would like to both use the modern Leica lenses and use a bunch of Sony FE lenses. I think such a camera would have cover glass that was halfway between the stock cover glass and Kolari v2. I think a number of Leica M lenses would do well with such a camera and it wouldn't hurt Sony FE lenses much if any. Good Leica M lenses I think would likely include the WATE, the 21 lux, the 24 lux, the 28 lux, the ZM 35 f/1.4, the 35 lux FLE, the 50 AA, the 75AA, the 90AA, and the 135 APO. All these lenses already do pretty well on a stock A7rII, but would like improve noticeably with such a camera. I don't think the change would affect Sony FE lenses much at all either. I may be the only one, but I don't think so, and this is the camera that I would like.
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