p.5 #1 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
Juha Kannisto wrote:
I have a Shoten helicoid adapter which looks exactly like the Yeenon and both have 6mm helicoid extension, I think they are the same with different branding. It's not thin, I think it's thicker than Voigtländer adapter (close to Rayqual). Mine does not have an infinity lock though that some Yeenon's have (not all). I don't actively use this adapter as I think the CV adapter is better.
Yes I *think* Shoten is Yeenon with Japanese branding and some extra price...
What do you think is better about the CV? I have a Yeenon, and as far as I can see there's no difference in quality with the CV..
p.5 #3 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
As you can see, the center is very similar while the mid-zone and extreme corner actually deteriorates with the PCX2500!! I would imagine the PCX2000 would give even worse results.
I also tested with the PCX5000 and it performed almost as good as the lens naked. Previously I thought the 5m was better than no PCX because I had issues with focus shift.
The simulation was all wrong for this one but I think it's because this lens has an unique optical design. I hope somehow could explain what's going on here.
p.5 #4 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
So when I did big bronco I focused on center for the whole aperture series and with the PCX 5000 we do see a improvement. Two fold question if we repeated the same focus wide open and leave it alone are we correcting the focus shift or are we correcting both the shift and the FC. it maybe worth a test to focus wide open a leave it there because we certainly say improvement like that but it felt to weak a correction. Makes you wonder because it’s not exactly logical.
p.5 #5 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
I’ll repeat what I said in the last email Fred. It may explain it. At least a thought I had all along
So I’ve been thinking about this all along. If you look at the 28 and 35 the front elements are opposite each other the 35 is concave so a correction glass our filter should be opposite which it is.
The 28 is convex or a bubble so the correction should be opposite a concave facing in and not out like our correction filter . In short it should be flat facing subject and convex facing toward sensors . If we look at a lens cut away you see that
p.5 #6 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
GMPhotography wrote:
So when I did big bronco I focused on center for the whole aperture series and with the PCX 5000 we do see a improvement. Two fold question if we repeated the same focus wide open and leave it alone are we correcting the focus shift or are we correcting both the shift and the FC. it maybe worth a test to focus wide open a leave it there because we certainly say improvement like that but it felt to weak a correction. Makes you wonder because it’s not exactly logical.
If a lens has focus shift, I don't think we should focus wide open and shoot an aperture series, hoping the front-lens fixes some of that shift. I think it would make more sense to remove all filters and let this baby be free.
Seriously, the focus shift is a characteristic of the lens. It was designed like this to perform on a Leica body.
p.5 #8 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
GMPhotography wrote:
I’ll repeat what I said in the last email Fred. It may explain it. At least a thought I had all along
So I’ve been thinking about this all along. If you look at the 28 and 35 the front elements are opposite each other the 35 is concave so a correction glass our filter should be opposite which it is.
The 28 is convex or a bubble so the correction should be opposite a concave facing in and not out like our correction filter . In short it should be flat facing subject and convex facing toward sensors . If we look at a lens cut away you see that
I see what you are saying BUT, I tested the PCX 2500 convex facing out and then in and got the same exact results. That's the first thing I tried. Either I got a bad PCX from OptoSigma which is very unlikely, or this does not work with this lens.
p.5 #9 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
Fred Miranda wrote:
If a lens has focus shift, I don't think we should focus wide open and shoot an aperture series, hoping the front-lens fixes some of that shift. I think it would make more sense to remove all filters and let this baby be free.
Seriously, the focus shift is a characteristic of the lens. It was designed like this to perform on a Leica body.
Lol yea end of day I agree let the baby fly solo.
I’m just damn stubborn and want to figure this out. Lol
I really like this lens a lot. So like to keep it for sure
p.5 #11 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
Fred Miranda wrote:
I see what you are saying BUT, I tested the PCX 2500 convex facing out and then in and got the same exact results. That's the first thing I tried. Either I got a bad lens from OptoSigma which is very unlikely, or this does not work with this lens.
Than I said it wrong when you face it in the bubble faces in. So bubble of lens and bubble of filter facing each other
What I’m saying is bubble of lens should be opposite of filter or let’s say a big dent facing in,its concave facing in towards lens. They make filters like that. Not what we bought
p.5 #14 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
Born optimist. Lol
More bright side . Maybe one of the better 28mm lenses we can use. There is only one other lens in 28 I Love is the Leica 28mm F 2 summricon. But I need a real job for that one. Lol
p.5 #15 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
GMPhotography wrote:
Born optimist. Lol
More bright side . Maybe one of the better 28mm lenses we can use. There is only one other lens in 28 I Love is the Leica 28mm F 2 summricon. But I need a real job for that one. Lol
Well, I just PMed Haruhiko about this. Maybe he can shed some light.
p.5 #17 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
DavidBM wrote:
Yes I *think* Shoten is Yeenon with Japanese branding and some extra price...
What do you think is better about the CV? I have a Yeenon, and as far as I can see there's no difference in quality with the CV..
I once ran some comparison test with one of my lenses between CV and Shoten and it looked like my Shoten was adding some decentering effect, i.e. one side was not as good as it was with CV especially towards the edge. After that I always kept using the CV when I needed close focusing, and never used the Shoten. It could just be some unit issue with my Shoten and I didn't really test it extensively.
Another thing is that the CV has an infinity lock (though it doesn't help for adjusting infinity but can keep the adapter locked at its "unextended" position) and Shoten doesn't, and Shoten is moving around quite freely (doesn't need much force to rotate at all), so I'm not feeling as comfortable about Shoten staying put at the infinity position without some attention.
p.5 #18 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
Aside from being able to use the original hood and front cap, the lens 'naked' allows us to use any M to E adapter including the helicoids like Hawks and Voigtlander's own VM-E close focus adapter
I could be totally wrong about this but my theory is that the CV 28/2 Ultron optical design is not sensitive to a sensor stack thickness just like the CV 15/4.5 III M-mount.
Have you noticed the CV 15 M-mount works great on Leica and Sony? I think the same applies here.
p.5 #19 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
Fred Miranda wrote:
Aside from being able to use the original hood and front cap, the lens 'naked' allows us to use any M to E adapter including the helicoids like Hawks and Voigtlander's own VM-E close focus adapter
Yea we can use that adapter off eBay I ordered today for the 28mm since it’s .7 now
p.5 #20 · Voigtlander Ultron 28mm f/2 Lens tests with PCX Front Filter
Juha Kannisto wrote:
I once ran some comparison test with one of my lenses between CV and Shoten and it looked like my Shoten was adding some decentering effect, i.e. one side was not as good as it was with CV especially towards the edge. After that I always kept using the CV when I needed close focusing, and never used the Shoten. It could just be some unit issue with my Shoten and I didn't really test it extensively.
Another thing is that the CV has an infinity lock (though it doesn't help for adjusting infinity but can keep the adapter locked at its "unextended" position) and Shoten doesn't, and Shoten is moving around quite freely (doesn't need much force to rotate at all), so I'm not feeling as comfortable about Shoten staying put at the infinity position without some attention....Show more →
Interesting. My Yeenon is the older one without infinity lock (the newer ones do have it) but the resistance is just perfect - that's what I like about it - silky smooth firm brass helicoid. No skew. I just tested it for infinity because @phillip reeve was wondering if it could be used with lenses with front filters, but sadly infinity is at (one on M) and just before (on another) the hard stop.Maybe Shoten is not Yeenon (or as you say unit issue). It's possible it isn't: there are a ton of CV clones out there (Tinray etc) which the Shoten could be. But only Yeenon, as far as I know, makes a range of rather nicely engineered designs of their own...
True, I've been dying to use that hood!