p.94 #1 · Sony A7 and A7r Full Frame with Canon Lenses
wow, very nice idea and job done with the velour. Seems a lot better indeed !
I wouldn't be surprised if we see a metabones v4 like this in a few months. I guess A7R users are putting more stress on such adapters and will find all misconceptions ;-)
Really a nice thread with lot of infos and everyone tries and finding, in a constructive discussion. Really appreciated, thanks all ;-)
p.94 #2 · Sony A7 and A7r Full Frame with Canon Lenses
Awesome information and diagram Marc. I wonder why Metabones mills that threaded pattern in the cylinder of the adapter. Even though it's painted black it's rather reflective on my copy.
p.94 #3 · Sony A7 and A7r Full Frame with Canon Lenses
FYI, the RJC adapter has felt lining at the side of the rectangular light path opening but not at the front or rear of the baffle. I believe that is more crucial in suppressing contrast robbing flare.
p.94 #4 · Sony A7 and A7r Full Frame with Canon Lenses
marc aurel wrote:
Hi beetlephoto,
I wrote the topic on Luminous Landscape Forum you linked:
A7R+TS-E 24: Internal reflections in Metabones III adapter and what could help
I post it here to share it with the ones who are not registered on LL. So:
I made a comparison with TS-E24 II on A7R and 5DIII, using shift. In the centre of the unshifted lens, the A7R has more resolution. Most obvious in the meander of the tympanon and the grid in the window. In the extreme corners of the shifted image resolution of both cameras is very close.
But additionally there is a degradgation of contrast in the shifted area in the A7R image compared to the 5DIII - the A7r image looks worse which I didn't expect - the black isn't really black. I suspected internal reflections in the adapter - something that has been reported about the TS-Es in another forum too. So I bought some self-adhesive velour to cover the interior of the metabones - Canon uses something similar for the interior of the TS-Es. I repeated the test. It was difficult to find a day with similar weather (no direkt sun), so the test is not perfect (light was a bit more contrasty on the second test).
I used tripod. Focused on extremes corner with live view. Raws converted in Lightroom 5.3. Adjusted white balance a bit to make images look similar. Sharpening for all: Amount: 50 - Radius: 0,7 - Detail: 30 - Mask: 4. Test 1 is before, Test 2 after changing the interior of the adapter. 100% crops (I tried up- und downscaling one or both to match sizes; results were similar).
In my eyes one can clearly see that in Test 1 the A7R image of the shifted area is less contrasty. In Test 2 - with the metabones with velour - it isn't. A7R still doesn't show a resolution advantage in the extreme corners - maybe the lens doesn't give enough resolution there. But it's not worse than the canon any more. And in the centre and most other parts of the image the A7R is much better.
I suspect that TS-E causes more reflections than other lenses beacuse the larger image circle hits more surfaces of the adapter interior.
I tried to visualize what happen's with that combination. Section unshifted and with full shift (see image below). With its image circle of 67mm the TS-E hits a lot of surfaces inside the metabones that can reflect. Maybe the rear element of the lens reflects back to the sensor.
marc aurel...Show more →
Awesome, thanks so much!!! I've printed your diagram and will cut my velours tomorrow. Great tutorial.
p.94 #5 · Sony A7 and A7r Full Frame with Canon Lenses
Just got a news letter from one of the guides that took us to Iceland who has a D800 and recently bought the A7R and he has been posting his finding so far. He says his adapted Nikon lenses and Zeiss for Nikon lenses are tack sharp and has not had any adapter issues. Can't recall the adapter off the top of my head. He's write up is very good and he's still doing field testing. It's not all rosess though but he wants to do more testing before passing final judgement. One thing is battery life is pathetic and he said waking the camera up form sleep can take a random amount of time, but often many seconds, often quickly.
p.94 #6 · Sony A7 and A7r Full Frame with Canon Lenses
Fred Miranda wrote:
Thanks for posting this here Marc!
I encountered the same low contrast issue with the TS-E 17mm even with the lens unshifted.
I glued your printed 1:1 diagram on the back of a black felt sheet and was able to precisely make the cutouts. It fits the adapter great.
I am waiting for a new Metabones copy to post more tests because the one I have is clearly tilted.
Fred
Have you tried adjusting those 6 screws holding the lens mount in place? Looks like a place where the mount can be off spec very easily.
But, reading between the lines of Roger Cicala's test HERE I think there might be something else going on. Look at his results with the D800E and Nikon glass. Corner sharpness is almost 50% less than center sharpness (Avg MTF50 Lp/IH numbers). That was the case with the Zeiss 50mm F2 lens and the Nikon 35mm 1.4 at optimum apertures, 2 of the best lenses for the Nikon. So the problem might the sensor/physics.
I was impressed with the results of the A7R and the native Sony FE lenses. Wow.
p.94 #7 · Sony A7 and A7r Full Frame with Canon Lenses
snapsy wrote:
Awesome information and diagram Marc. I wonder why Metabones mills that threaded pattern in the cylinder of the adapter. Even though it's painted black it's rather reflective on my copy.
Thanks Marc! I am adapting from Nikon to A7, and am having a lot of problems. I note that my Fotodiox Pro has the same threaded pattern in the rings. I am going to cover that and see if it helps. The threaded pattern is quite reflective in the Fotodiox, too.
Interesting thread, and kudos to you on your ingenuity.
p.94 #9 · Sony A7 and A7r Full Frame with Canon Lenses
I think Marc's work is going to be extremely useful for tilt-shifts and probably help with certain other lenses. From what I've tested, though, it's not going to make a huge difference overall. I took a metabones 3 adapter yesterday and tested a Canon 24-70 f/2.8 at 70, then the 35mms I tested earlier (Zeiss f/2, Canon 35 f/2 IS). Then I painted the inside of the adapter with optical blacking and retested, then did it with fuzzy black tape according to Marc's pattern and retested. No difference in Imatest at all.
What theSuede and others said earlier is certainly the bigger issue. I've talked to two well-known lens designers, an adapter manufacturer, and someone who does sensor glass modifications about. All 3 agreed the off-axis issues are about cover glass thickness and composition.
For lenses with exit pupils near the rear (most wide angles and M mount, many others) off-axis performance isn't going to be as good as center performance. The good news is almost all tilt-shifts have exit pupils way up in the lens, so that should do better.
p.94 #10 · Sony A7 and A7r Full Frame with Canon Lenses
RCicala wrote:
What theSuede and others said earlier I've talked to two well-known lens designers, an adapter manufacturer, and someone who does sensor glass modifications about. All 3 agreed the off-axis issues are about cover glass thickness and composition.
Perhaps Ziess can come to Sony's rescue with an aspherical sensor cover which would straighten out those pesky light rays.
p.94 #12 · Sony A7 and A7r Full Frame with Canon Lenses
RCicala wrote:
I think some people are looking into an adapter with corrective optics. Or so I hear
That is great news!
So, perhaps we will have an adapter that corrects the off-axis issues caused by the thickness of the glass?
BTW: With Marc's anti-reflective velour idea I'm getting way better contrast in the corners when using the 17mm and 24mm TS-E (shifted and unshifted). With other lenses like the the Samy 14mm or 24-70 II, there is no noticeable difference with the velour or without.
Fred
p.94 #13 · Sony A7 and A7r Full Frame with Canon Lenses
Fred, I'm told it's fairly simple and straightforward to do - at least that's what people a lot smarter than me say. I can't follow the math once they start using all those Greek symbols and stuff.
p.94 #15 · Sony A7 and A7r Full Frame with Canon Lenses
Fred Miranda wrote:
BTW: With Marc's anti-reflective velour idea I'm getting way better contrast in the corners when using the 17mm and 24mm TS-E (shifted and unshifted). With other lenses like the the Samy 14mm or 24-70 II, there is no noticeable difference with the velour or without.
Fred
Hi Fred -
Roger Cicala reports the same. Seems like only lenses with extreme large image circle have the problem with the metabones.
I want to add another observation here: I recently bought a Zeiss-Contax PC-Distagon 35mm which I use via Adapters on 5DIII and the A7R. The Adapter for the E-Mount for A7R is by Novoflex and has a simple form: just a tube - similarly structured surface as the metabones. Even with full shift I see no degradation of contrast in the corners as with the TS-Es.
So the problem could be the geometry of the metabones: That platform before the rectangular opening begins is parallel to the rear element of the lens. Could be that the main reflections happen between that surface and the rear element (and maybe the blank metal of the bajonet of the lens).
By the way and a bit off topic:
The PC-Distagon 35mm is great on the A7R. It only offers 10mm of shift and no tilt, but the shifted corners are quiet sharp - in my eyes the extreme corners are better than the TS-E 24 II. It has more distortion, but the free Alpa plugin for Photoshop has a profile which works great. In my eyes the best option for that focal length. It's rare though and I was just lucky getting one in good condition.
p.94 #16 · Sony A7 and A7r Full Frame with Canon Lenses
You could you black flocking material that my be better than your velour. I used it inside my Globuscope 4x5 camera. They use it in telescopes and it looks darker than the pictures you guys have posted.
p.94 #18 · Sony A7 and A7r Full Frame with Canon Lenses
secondclaw wrote:
I've been experiencing pretty awful sensor flares with Metabones3-adapted canon lenses on A7R. Is the issue really with the sensor, or is adapter playing some role in the flare? I don't have any native FE glass or another adapter to test.
This is from last night testing 24-70 MK2 ....
As we discussed in the last few pages, the usage of adapter or adapters of various brands on this camera is not all that seamless and issueless when compared to usage of your native Canon lens(es) on your Canon body... . Maybe you can reduce the flare by adding flocking material or by putting self-adhesive velour fabric on the light path of the adapter, as mentioned in the previous page. Another way to find out whether it is an adapter issue would be to compare the exact same lens under the exact same conditions on the A7r and your FF Canon camera. Yes, there is a difference in resolution due to the difference in MP of the sensor but the flare reproduction should be very similar if not the same.
p.94 #19 · Sony A7 and A7r Full Frame with Canon Lenses
AGeoJO wrote:
Another way to find out whether it is an adapter issue would be to compare the exact same lens under the exact same conditions on the A7r and your FF Canon camera. Yes, there is a difference in resolution due to the difference in MP of the sensor but the flare reproduction should be very similar if not the same.
That's a good idea ... though I have to admit I've never noticed sensor flare with 5D2 - or maybe it just wasn't very pronounced. I should try that velour method posted earlier in case adapter's reflection contributed to the flare.
p.94 #20 · Sony A7 and A7r Full Frame with Canon Lenses
secondclaw wrote:
I've been experiencing pretty awful sensor flares with Metabones3-adapted canon lenses on A7R. Is the issue really with the sensor, or is adapter playing some role in the flare? I don't have any native FE glass or another adapter to test.
Samuli is reporting some undesirable flare effects as well (post, look at image 9 and down). First it was with the native 35mm Sony lens but I think it's been reported with other lenses as well.
