By the way, I wish correcting color shift is as easy as correcting vignetting - with sliders. However I have color shift that is rectangular shape making it difficult to just using sliders.
I think we need something like the "white shading" files used in medium format digital. You take a shot of a white wall, evenly lit, and can use that to subtract the colourcast from images. It ought to be doable in Photoshop as well, with a script perhaps.
kolen wrote:
By the way, I wish correcting color shift is as easy as correcting vignetting - with sliders. However I have color shift that is rectangular shape making it difficult to just using sliders.
Yeah I was wondering about that. I am afraid that new app from Sony for lens correction wan't be sufficient?
But who knows?
I have taken the liberty of updating the OP with the following remarks - just in case someone chimes in and this thread survives
================================
U P D A T E - NOV 22 - 113 pages later
================================
This thread asked for it and got its fair share of speculation and corner pixel peeping galore @ 36MP. Summary:
- A7 is clearly better than A7r for WA RF lenses
- Many RF lenses below 35 show corner/edge issues (*), worse so on A7r than on A7.
- Most RF lenses above 35mm seem just fine
(- SLR lenses all seem fine, including WAs)
- - - -
(*) many of the RF WA lenses deemed unusable for landscaping will perform just excellent for short DOF photography.
- - - -
Two very fine cameras indeed. For me personally 24MP no doubt, not only because of WA RF's performance.
These cameras are not Leica replacements. Leica fosters better for the type of lenses particular for this thread. In house software corrections are part of that but not all. Leica is still Leica. But the Sonys bring superior resolution, dynamic range, size advantage, and usability to the table. Add to that within parenthesis, (affordability).
kolen wrote:
But I am more concerned with the workflow on correcting the corner color shift. From what I've seen, it should depends on the aperture, isn't it?
If that's true, is it possible to create one profile to correct all different aperture and focus distance? If not, how Leica do it in camera?
There is a tiny little dot next to the Leica logo dot which can measure the light independently, and can thus be used to estimate the aperture. In the Leica DNGs, there is a field for this estimated aperture, although it is not part of the public tags.
sebboh wrote:
to use my g28 on my nex-7 i made a separate profile in pic for every aperture at infinity and then another one for every aperture at ~1.5 meters. it took about 2 min. there really isn't enough change from one focal distance to another to justify more than one set of near profiles and one set of far profiles. many people seem happy with just one profile for one aperture at infinity. when i decide a picture needs it i can apply the appropriate profile with a few clicks in LR.
How do you create these profile pics? Take a picture through a white sheet of paper of the sky? take a picture through an expo disc of the sky?
theSuede wrote:
Yes, you're correct in assuming/stating that the statement "offset microlenses don't do any good" is indeed rubbish.
Sorry Joakim to pick a sentence from your normally enlightening posts but that is pure bollocks.
This thread is about comparing RF WAs on the A7 and the A7r. There's absolutely nothing showing that the presence of offset microlenses in the A7r makes it better than the A7. On the contrary.
naturephoto1 wrote:
I have sent an e-mail off to Stephen Gandy of Cameraquest regarding the question of the removal of the lens hood or purchasing the lens without the hood attached. Hopefully I will receive a response. If not, I will give him a phone call.
Rich
Here is my e-mail discussion with Stephen Gandy of Cameraquest and myself about the lens hood for the Voigtlander 21mm f1.8 Unitron:
Hi Stephen,
With the release of the new Sony A7 and A7r cameras, many of us on Fredmiranda.com are looking for an M mount lens in the 21mm focal length that will perform well on these cameras. Beside the weight issue there is the question of the permanently attached petal lens hood. Is there a way of removing the lens hood or since you are the distributor and also provide repairs, could the lens be purchased directly from you without the hood attached?
That is an answer that I would like to share with other members of the Fredmiranda.com community and could aid us in making our decision of purchase. There could be many of these lenses ordered by members.
Thanks very much.
I look forward to your response.
Sincerely,
Rich Nelridge
This is Stephen's response:
Hi Richard!
The attached 21/1.8 hood was engineered to reduce size and weight compared to a detachable hood.
While my tech could probably find a way to remove it, frankly most users would not like the result since
1) it would be ugly 2) the hood would no longer be usable if desired.
Like all of the other in production Voigtlander lenses over $599, I am offering free USA next day delivery as well as including a premium B+W XS-PRO Nano Clear filter with the Voigtlander 21/1.8.
Please don't hesitate to contact me for other Voigtlander info.
BTW, there are also lots of Voigtlander and Sony A7/r discussions on my other site, www.RangeFinderForum.com
sculptormic wrote:
....
For the rest I hope my SLR wide alt lenses can give me hopefully some surprises. But I probably can be happy with the FEza 35 for a while.
And then all the lenses above 35mm could that be fun!
Anyway I have to wait one weekend more because the deliveryman went to the wrong doorstep, not at home, and my A7r was taken back as not deliverable. Life is a bitch sometimes
Could have been way worse. Imagine that your neighbor was at home. He/she got the parcel, opened it; saw the camera of his/her dreams and naturally 'forgot' to tell you about it..
If the A7(r) and other future FF-E cameras are successful, I bet that Sigma will step into the arena with a series of fast and affordable primes designed specifically for this mount. Maybe wishful thinking but...
p.113 #12 · A7/A7r - performance with WA RF lenses
sculptormic wrote:
Rich, I don't share your problems with the hood.
The problems with the hood relate to the usage of filters including rectangular Grad filters, square or rectangular ND filters, rotating variable ND filters, etc. Additionally, if a round 58mm filter jams or is over tightened, it could become exceedingly difficult to remove.
p.113 #13 · A7/A7r - performance with WA RF lenses
ebrandon wrote:
How do you create these profile pics? Take a picture through a white sheet of paper of the sky? take a picture through an expo disc of the sky?
and then you use the Adobe Flat Field plug-in?
i put a kim wipe (kleenex would be fine i'm sure) in front of the lens using a rubber band to secure it uniformly and flat then point the camera towards a clear blue sky and shoot through the aperture range.
yes, i'm using the adobe flat field plug-in.
kolen wrote:
Thanks. Then it means that you have to record the aperture you used in the field?
I tried to do it but it's very difficult for me. One way I managed to "remember" the aperture I used is to stick to F1.4 or 5.6 only, and by just looking at the images I can separate them. And occasionally I used other aperture and try really hard to remind myself when I get home this is F4, this is F4...
there's lots of ways to record the aperture in the field, but i don't do any of them.
the easiest way i can think of is to use hand signals and just take a picture of your hand before or after the shot making the appropriate signal.
if you don't remember you can always just guess and then change profile pics if it doesn't look right.
Nov 22, 2013 at 06:06 PM
Steve Spencer Online • • • • • • • Upload & Sell: On
p.113 #14 · A7/A7r - performance with WA RF lenses
Not jumping on you, but I don't see weaker corners in that image as much as just generally lower resolution across the frame than what the 28 cron is capable of. I think that city scene may be a victim of some atmospheric haze: if it was shot in China, I know from experience how often that's a problem. That said, I *still* see more edge detail than the options at that focal length on APS-C NEX.
I definitely see the 28 cron signature in that water scene poster earlier.
I agree that atmospheric haze in China can very well wreak havoc on images, but I don't think that is the whole story here. For me part of the cron signature is very gradual fall off from excellent centre sharpness. In this shot I see the sharpness fall off quickly about 3/4rds of the way across the frame and the edges just looks pretty weak when viewing the image as a whole. I think part of this is due to the excellent centre sharpness which in and of itself is a good thing, but when viewing the whole image exacerbates the look of the edges. I think if you put a centre crop next to the edge crop you would see a marked difference, more than I would expect for the cron, but maybe I am wrong. To me that would suggest it isn't just atmospheric haze, but rather the lens having a different look on this camera--one that personally I find less appealing.
p.113 #15 · A7/A7r - performance with WA RF lenses
sebboh wrote:
i put a kim wipe (kleenex would be fine i'm sure) in front of the lens using a rubber band to secure it uniformly and flat then point the camera towards a clear blue sky and shoot through the aperture range.
yes, i'm using the adobe flat field plug-in.
Do you set the focal distance at infinity, mid distance, or mfd when you do that? I imagine that the flat field plugin might result in undercorrecting or overcorrecting one way or another.
p.113 #16 · A7/A7r - performance with WA RF lenses
Jabberwockt wrote:
Do you set the focal distance at infinity, mid distance, or mfd when you do that? I imagine that the flat field plugin might result in undercorrecting or overcorrecting one way or another.
i have one set at infinity and one set at around 1.5m. i use whichever is closest to actual focus in the shot.
p.113 #17 · A7/A7r - performance with WA RF lenses
naturephoto1 wrote:
The problems with the hood relate to the usage of filters including rectangular Grad filters, square or rectangular ND filters, rotating variable ND filters, etc. Additionally, if a round 58mm filter jams or is over tightened, it could become exceedingly difficult to remove.
Rich
Ah sure, I see. I always forget about using filters.
p.113 #18 · A7/A7r - performance with WA RF lenses
The perspective (pseudo-conclusion) that the WA RF's perform better on the A7 moreover than the A7R ... what is it that this is actually being attributed to? I'm not quite following WHY that would be the case.
It kinda sounds like saying that a ZF would perform better on the D700 than the D800E.
p.113 #19 · A7/A7r - performance with WA RF lenses
RustyBug wrote:
It kinda sounds like saying that a ZF would perform better on the D700 than the D800E.
NEX cameras varied in sensor topping arrangements, and potentially in micro lens layout, so I wouldn't be surprised if the A7 and A7r also have differences.
p.113 #20 · A7/A7r - performance with WA RF lenses
RustyBug wrote:
The perspective (pseudo-conclusion) that the WA RF's perform better on the A7 moreover than the A7R ... what is it that this is actually being attributed to? I'm not quite following WHY that would be the case.
It kinda sounds like saying that a ZF would perform better on the D700 than the D800E.
there's plenty of direct comparisons showing less color shift on the a7 vs the a7r. there's more confounds with comparisons of smearing between the two (in the comparisons i've seen) so i'm not so certain of that.
