There are always tradeoffs in just about everything. I use NDs and polarizers for certain effects, but I'm sure there is some degradation of image quality when they are used. It comes down to benefit ratio....is it a net positive or negative. I definitely wouldn't suggest doing something that yields little benefit at tangible detriment. Where that line is drawn is a little subjective to each person.
Anyway, I wonder the same thing. To me ray angle may still have some role to play, given the challenges of a digital stack. And then like you say, within the lens itself. Maybe certain near UV wavelengths aren't handled consistently across the frame, and the UV filter is just attenuating those wavelengths in advance of the light entering the lens.
I can honestly say I don't know, but I'm intensely curious.
-Tim
DWOfPaul wrote:
I agree at the end of the day it's the results that matter. I have to admit though I do find it a bit confusing to be buying UV filters after always thinking their basically a gimmick.
Another taught I had on this is I wonder if it has something to do with blocking the UVC light from going into the lens from the start, VS trying to block the UV light at the rear with the sensor stack. We know light passing through our lenses can get manipulated which leads to issues like CA. Maybe the UV light is getting mixed up to so that by the time it hits the sensor stack some of it is no longer in the frequency range that is blocked by the sensor stack. ...Show more →
Looks like an RGB trick. Combine the entire image with the magnet color, then filter the entire image to cut out the unwanted color in the finishing process (post-processing). Finally there is no CA.
Does CameraQuest and Photo Village here in the US get their lenses right around that date, and then ship pretty close to that timeframe, or do they lag a few weeks? I can't remember based on my past Voigtlander purchases.
-Tim
Juha Kannisto wrote:
Cosina announced the official release date for the E-mount version of APO 35/2 today. It’s 9th of April, earlier than what I expected.
I think they usually get them close to same time as official Japan release date. Might be a couple of days after Japan.
tsdevine wrote:
Does CameraQuest and Photo Village here in the US get their lenses right around that date, and then ship pretty close to that timeframe, or do they lag a few weeks? I can't remember based on my past Voigtlander purchases.
I did some testing with my Zeiss 50mm f2 ZF and my Zeiss 35mm f2 ZF on my Sony A7rII. I can see a difference in the pictures with and without the Zeiss UV filter in front of the lens. This is starting to make me learn towards maybe it does have something to do with the Sony sensor stack. Otherwise I would have expected to not see a diffrence putting the Zeiss UV filter on a Zeiss lens. I would figure if Zeiss had a coating that would make for clearer photos they would have applied it to their lenses, if they felt it was needed.
I think the next test I want to do is try the Zeiss 35mm and 50mm lenses with and without the Zeiss UV filter on my Nikon d800e. If I don't see a difference on my Nikon then it has to have something to do with the Sony camera.
I would imagine the filtering is additive, so it will knock down some of the spectrum in combination with what the stack filters. So I'm not sure I'd expect no visible difference.
DWOfPaul wrote:
I did some testing with my Zeiss 50mm f2 ZF and my Zeiss 35mm f2 ZF on my Sony A7rII. I can see a difference in the pictures with and without the Zeiss UV filter in front of the lens. This is starting to make me learn towards maybe it does have something to do with the Sony sensor stack. Otherwise I would have expected to not see a diffrence putting the Zeiss UV filter on a Zeiss lens. I would figure if Zeiss had a coating that would make for clearer photos they would have applied it to their lenses, if they felt it was needed.
I think the next test I want to do is try the Zeiss 35mm and 50mm lenses with and without the Zeiss UV filter on my Nikon d800e. If I don't see a difference on my Nikon then it has to have something to do with the Sony camera. ...Show more →
These Voigtlander lenses, there they go again causing trouble for Sony even before they are released. Sony really should give the responsible Cosina executives a stern talking to. It's just not cricket when you're on a sticky wicket.
tsdevine wrote:
Then what is the explanation? Is in the increase filtering between 380-400nm? Is there cumulative effect, where the filter and stack together are additive in nature? Could it be just my cameras? Is there some fluorescence in these lenses? Or with certain wavelengths the lenses are skewing the wavelengths towards the edges and corners? What are the hypothetical causes that haven't been ruled out?
Is your test average this across the whole frame or sampling a portion? This curve is exactly the same in the center and at the edges and corners, with no deviation, including with a lens mounted where ray angle may come into play more?
I'll revise my post and soften my comments around the "why". I will say "no one knows" from now on, that seems to be the safest bet.
My last question would be, based on your test, do you feel there should be as noticeable change between bare lens and Kenko filtered lens photos? In other words, is your test confirmed in the test shots I have posted and vice versa?
Here is more info about the Lensrentals test for the Zeiss filter graph I posted:
I only mentioned the manufacturer posted transmission graphs and the Lensrentals one. If the Lensrentals test isn't transparent enough in how the test was done, I guess we have to ignore their test.
Tim, I'd have to agree with you that ray angle has to be playing a part here: if not, then why is the problem worse in the corners?
Intuatively, it makes sense also, as the refraction of light changes based on the angle of incidence; there is clearly some interaction going on here between lens optics, wavelength, ray angle, coatings etc. If you think about the degree to which UV light penetrates the water surface on a lake for instance - ray angle has a big effect on that (as a rough analogy).
Also, anecdotal evidence seems to suggest it effects the really high performing lenses the worst (Tamron 35, Voigt apo's, Loxias etc), which makes sense - as they perform the best into the smallest point-spread-functions of the near-UV spectrum
philip_pj wrote:
These Voigtlander lenses, there they go again causing trouble for Sony even before they are released. Sony really should give the responsible Cosina executives a stern talking to. It's just not cricket when you're on a sticky wicket.
English is my second language only. I've also never visited a cricket field but I think I figured it out:
Are yo saying that Sony should have a serious conversation (mainly going one way) with Mr. Hirofumi and that it's not fun being a photographer when the tools don't play well together? Or, is there another way to interpret your message?
(I admit I first started to think about insects gotten caught in sticky paper traps... didn't make much sense though.)
Maybe they should talk to Zeiss (lens series admittedly manufactured by Cosina) and Tamron and perhaps a few more? Then who is causing troubles for who?
I'm looking forward to similar test images with cameras of other brands. If Paul [DWOfPaul] checks how his Nikon works maybe somebody else can chime in trying a Canon camera?
Sarcasm or not, I would think the lens manufacturers like Cosina and Tamron would have the chops to figure it out, without Sony. They would just have to be aware of it first.
Ultimately, at the end of the day, I only really notice this on a few lenses.
You have to realize that Cosina are making lenses for the Sony platform and not the other way around. They should be a bit more careful especially with their so called premium lenses. They have to justify that they can be a cut above 7Artisans, Laowa and the like, otherwise they can stick to serving Leica M as they have done before.
philip_pj wrote:
These Voigtlander lenses, there they go again causing trouble for Sony even before they are released. Sony really should give the responsible Cosina executives a stern talking to. It's just not cricket when you're on a sticky wicket.
tsdevine wrote:
I would imagine the filtering is additive, so it will knock down some of the spectrum in combination with what the stack filters. So I'm not sure I'd expect no visible difference.
I got to do some quick test with the Zeiss 50mm f2 on the Nikon D800e and I can't see any noticeable differences in the images with and without the Zeiss UV filter.
If the weather corporates this weekend I will try to do some controlled test, and share some images.
So far I think I will be buying some more Zeiss UV filters to add to my Sony Kit. I also think this confirms I will be getting a Z7ii before I add a second body to my Sony Kit. Not to make this into a Nikon vs Sony debate, but I defiantly want to better understand this issue before fully committing to a mirrorless system.
The wavelength that Sony filters via the stack may be slightly different than Nikon. But unless you're seeing magenta corners/edges, I'm not sure what you see on the Sony with the Zeiss 50 is a problem. (You notice a difference, if so, is it really bothersome?) I can't remember if you posted samples.
The magenta cast though seems problematic, but it seems as though that is a lens issue. I only see this on a couple of lenses, at least to a point where it becomes problematic in my mind.
DWOfPaul wrote:
I got to do some quick test with the Zeiss 50mm f2 on the Nikon D800e and I can't see any noticeable differences in the images with and without the Zeiss UV filter.
If the weather corporates this weekend I will try to do some controlled test, and share some images.
So far I think I will be buying some more Zeiss UV filters to add to my Sony Kit. I also think this confirms I will be getting a Z7ii before I add a second body to my Sony Kit. Not to make this into a Nikon vs Sony debate, but I defiantly want to better understand this issue before fully committing to a mirrorless system....Show more →
The comparison lens aficonados will want to see is this one against the new GM 35/1.4. As much as anything else it will be a test of Sony's 'MTF', which indicates near parity with the data for the E version of the CV 35/2 APO - wide open for both lenses.
But to put things in Sony's perspective here is their blurb for the GM lens:
'..this compact lens fits easily in the palm of your hand and weighs a mere 524g (18.5 oz). The FE 35mm F1.4 GM offers excellent mobility and handling in the widest possible range of environments and shooting conditions.'
It's a matter of standards. Tell it to the Leica users, Sony. At 352 grams, maybe you could say the CV 35/2 E lens weighs a 'merest mere', as it is just 67% of the GM's weight, before adding filters (49mm vs 67mm) and lens cases to the mix. I'm actually looking forward to this one, despite my travel being covidised out for now.
Someone already got this lens...
He said he was surprised by the much better vignetting control VM35 APO provides, while VM50 APO shows severe vignetting (both on M body).
Even adapt this lens to 44x33 with MFD (50cm), the vignetting is still in acceptable level.
