nehemiahphoto wrote:
Because the UT (works out to 0.9) is not as thin as the NKIR v3+ (0.75), and while this may not affect many modern RF lenses, other lenses like the Contax G line I believe will do better with thinner while not negatively affecting most current M glass. Additionally, the color management/WB issues seem better on the NKIR versus the Kolari with the UT vs. V3+. On top of that, NKIR told me they are trying out a newer thinner (V5), and that filter is (0.58), so I am hoping for further improvements on those more difficult lenses, so I am hoping that passes into production and I get that (should know soon). Lastly, I can test my NKIR (either V3+ or V5) against Sebboh's Kolari UT as we live near and are friends. The NKIR mod is also cheaper a bit and less of a known quantity, which naturally heightens my interest as well. ...Show more →
That makes sense Nehemiah. Will this coverglass + filter be even thinner than the native Leica M sensors?
LarsHP wrote:
Honestly, it was a surprise to me that the Ultron II was sharper across the frame than my Summicron-M Asph II (both wide open). In terms of bokeh, they both have their strengths and weaknesses; the Ultron smoother in the central area, the Summicron in the sides and corners at medium focus distance. My biggest complaint about the Ultron II is that its vignetting is so strong that I consider it roughly a f/2.4 lens with a small hot spot in the center.
“f/2.4 lens with a small hot spot in the center” describes the Ultron perfectly. The obsessive devotion to making tiny lenses at the cost of excessive vignetting turns what could have been a superb lens into a merely excellent one.
nehemiahphoto wrote:
Because the UT (works out to 0.9) is not as thin as the NKIR v3+ (0.75), and while this may not affect many modern RF lenses, other lenses like the Contax G line I believe will do better with thinner while not negatively affecting most current M glass. Additionally, the color management/WB issues seem better on the NKIR versus the Kolari with the UT vs. V3+. On top of that, NKIR told me they are trying out a newer thinner (V5), and that filter is (0.58), so I am hoping for further improvements on those more difficult lenses, so I am hoping that passes into production and I get that (should know soon). Lastly, I can test my NKIR (either V3+ or V5) against Sebboh's Kolari UT as we live near and are friends. The NKIR mod is also cheaper a bit and less of a known quantity, which naturally heightens my interest as well. ...Show more →
What inclines me to go with the NKIR rather than the Kolari conversion was a very long FM post a while ago from a member in Hong Kong (IIRC) which was packed with sample images made with a wide range of lenses on an NKIR converted camera. And the images not only looked great but the member specifically stated that—as nehemiahphoto says—color management/WB issues were minimal.
Wouldn't that introduce smearing and other issues in the sides and corners with wide angle RF lenses too?
My understanding is that with angled light passing through (in this case at least two) glass surfaces, the light path will bend. Since different wavelengths will bend to different degrees => an optical nightmare outside the center.
freaklikeme wrote:
You could always just remove the filter stack completely and put the UV/IR cut filter on the end of the lens. It's film-era lens nirvana.
LarsHP wrote:
Wouldn't that introduce smearing and other issues in the sides and corners with wide angle RF lenses too?
My understanding is that with angled light passing through (in this case at least two) glass surfaces, the light path will bend. Since different wavelengths will bend to different degrees => an optical nightmare outside the center.
It hasn't so far (tested with the Distagon 18/4, Biogon 21/2.8, Elmarit-M 21/2.8 vI, and Biogon 28/2.8) but the wide RF's do require a "hot mirror" filter rather than a standard UV/IR cut. Kolari's latest filters are the best I've used for this purpose.
That said, modern mirrorless and M-mount lenses tend to take a big hit in this configuration, so you really have to love film-era lenses.
freaklikeme wrote:
It hasn't so far (tested with the Distagon 18/4, Biogon 21/2.8, Elmarit-M 21/2.8 vI, and Biogon 28/2.8) but the wide RF's do require a "hot mirror" filter rather than a standard UV/IR cut. Kolari's latest filters are the best I've used for this purpose.
That said, modern mirrorless and M-mount lenses tend to take a big hit in this configuration, so you really have to love film-era lenses.
Wait a minute. Are you talking about using a filter in the regular filter thread on the lens? If so, then I understand.
(I thought you suggested putting the filter on the rear of the lens.)
genji wrote:
What inclines me to go with the NKIR rather than the Kolari conversion was a very long FM post a while ago from a member in Hong Kong (IIRC) which was packed with sample images made with a wide range of lenses on an NKIR converted camera. And the images not only looked great but the member specifically stated that—as nehemiahphoto says—color management/WB issues were minimal.
Hi Jonathan,
White Balance is a piece of cake with the Kolari Vision UT sensor modification providing you make WB standards using a white card and store them in the memory of the camera for different Lighting Conditions. I have them saved in my Kolari Vision UT Sensor Modified A7rII and my Kolari Vision V3 Thin Sensor modified A7r for Daylight, Cloudy, and Shade conditions. If you need even more accurate WB adjustments for the conditions, you can photograph the White Card in the series to make your adjustments. Also, when I had Kolari Vision perform the UT sensor modification, Vivek (real Vivek) and I were stunned that the turnaround time for me in February of 2020 (just before the start of the Covid Pandemic) was about 1 week (from arrival at Kolari Vision to the return, but I live in Pennsylvania and Kolari Vision is in New Jersey only about 75 miles or so away). Also, I believe that Vivek has indicated the Kolari Vision UT sensor stack is more rugged (can take more abuse) than the NKIR modification. But, don't quote me on the last comment.
White Balance is a piece of cake with the Kolari Vision UT sensor modification providing you make WB standards using a white card in the memory of the camera for different Lighting Conditions. I have them saved in my Kolari Vision UT Sensor Modified and my Kolari Vision V3 Thin Sensor modified A7r for Daylight, Cloudy, and Shade conditions. If you need even more accurate WB adjustments for the conditions, you can photograph the White Card in the series to make your adjustments. Also, when I had Kolari Vision perform the UT sensor modification, Vivek (real Vivek) and I were stunned that the turnaround time for me in February of 2020 (just before the start of the Covid Pandemic) was about 1 week (from arrival at Kolari Vision to the return, but I live in Pennsylvania and Kolari Vision is in New Jersey only about 75 miles or so away). Also, I believe that Vivek has indicated the Kolari Vision UT sensor stack is more rugged (can take more abuse) than the NKIR modification. But, don't quote me on the last comment. ...Show more →
Thank you for the information and suggestions regarding the Kolari conversions, Rich. I’ll wait for nehemiahphoto’s report about his NKIR conversion before making a decision.
freaklikeme wrote:
You could always just remove the filter stack completely and put the UV/IR cut filter on the end of the lens. It's film-era lens nirvana.
I thought about this route, but I do want to use lots of current m glass as well and have a native/strong performance. If you take out the filter stack completely, lenses perform as native correct? Even picky WA RF film lenses?
LarsHP wrote:
Wait a minute. Are you talking about using a filter in the regular filter thread on the lens? If so, then I understand.
(I thought you suggested putting the filter on the rear of the lens.)
Yeah, just a front filter, though I did try creating rear filters for the Batis 18, Samyang 18, and Loxia 25- all miserable failures. I've only been successful with rear filters on lenses that were built to work with rear filters (the Nikon 16 FE, the Laowa 10-18, and the IRIX 15 with the Aurora glass filter holder replacement).
nehemiahphoto wrote:
I thought about this route, but I do want to use lots of current m glass as well and have a native/strong performance. If you take out the filter stack completely, lenses perform as native correct? Even picky WA RF film lenses?
As native might be a stretch. There's typically a vignetting penalty in using the front filters (even the hot mirror filters don't allow as much light to pass to the corners as a bare lens on a film camera does). It's probably better to say as close to native film performance as digital allows.
freaklikeme wrote:
As native might be a stretch. There's typically a vignetting penalty in using the front filters (even the hot mirror filters don't allow as much light to pass to the corners as a bare lens on a film camera does). It's probably better to say as close to native film performance as digital allows.
I am sorry, let me phrase my understanding and question more clearly: If you remove the filter stack which does significantly help film lenses, that hurts the native performance of current m glass. Is that correct?
nehemiahphoto wrote:
I am sorry, let me phrase my understanding and question more clearly: If you remove the filter stack which does significantly help film lenses, that hurts the native performance of current m glass. Is that correct?
Absolutely, though I will say M-mount lenses are really the last of modern lenses that take film performance into account. The MA, while backordered, is still actively produced, and Leica still wants to sell modern lenses to people buying that camera, so they tend to make more compromises biased to film-users and make up for those compromises in software on the digital M's. So, if you are going to adapt digital-age lenses to a bare-sensor digital camera, Leica's your best-bet so far as getting the most out of them. The mod is more impactful to the camera's performance with native mirrorless lenses.
freaklikeme wrote:
Yeah, just a front filter, though I did try creating rear filters for the Batis 18, Samyang 18, and Loxia 25- all miserable failures. I've only been successful with rear filters on lenses that were built to work with rear filters (the Nikon 16 FE, the Laowa 10-18, and the IRIX 15 with the Aurora glass filter holder replacement).
OK. This totally makes sense and affirms my understanding as posted above.
I actually have a Sony a7 which is full spectrum converted, and it did very well with the 28mm Summicron Asph II when using a hot mirror type filter in front of the lens. Resolution seemed to be even higher than the UT converted Z6 if I recall correctly.
