p.98 #1 · Sony A7 and A7r Full Frame with Canon Lenses
jcolwell wrote:
Hi John,
I agree with you on both counts; (i) nice cleaning by Achim, and (ii) I'm confused about this camera.
I would intend to use it for scenic, architecture, product, and still life photography. I would use manual focus lenses, most often with tilt and/or shift movements, with focal lengths from 17mm to 150mm.
Currently, my confusion is focused on two issues: (i) "shutter slap" IQ degradation for slow shutter speeds, and (ii) "lossy" compression of RAW files, which appears to contradict the meaning of "RAW".
Shutter vibration is an issue when shooting above 85mm from 1/15 until 1/125 shutter speed range. But you would need to inspect your files at 100% to see anything as the blur is minimal. However, It's noticeable above 200mm, especially if the camera base is not mounted on the tripod. (In the case of using an adapter mount or lens tripod mount).
Regarding the ARW files. Sony uses cRAW, which compresses the image and removes 'redundant' data. In that case it's lossy but in reality "visually" lossless. I have not yet encounter a file that shows any real compression artifact. Some were posted on the Alternative board but the issues were mainly post-processing.
I do wish Sony releases a firmware addressing both issues though.
p.98 #2 · Sony A7 and A7r Full Frame with Canon Lenses
Hi Fred,
Thanks for summarizing the 'shutter vibration' and 'lossy/lossless' compression issues.
I accept that the "shutter bounce" issue doesn't affect most images that I might take, but it could affect the "outer boundaries" of the range of shutter speeds and focal lengths that I expect to use. For example, if I crop a 150mm image, taken at 1/15 sec., which I do about twice a year. That's twice a year that I might take dozens of images with that combination of focal length and shutter speed.
An electronic first curtain shutter would certainly go a long way towards solving that part of the puzzle.
Regarding RAW files and compression, my understanding is that "lossless" compression works by removing "redundant" data. "Lossy" compression occurs when some kind of interpolation or extrapolation is involved, in order to reduce the amount of data that has to be saved. Ideally, there is no loss of important data; i.e. it's 'virtually' lossless. OTOH, I have lots of card space and lots of time for writing files, when I'm shooting the types of subjects for which I'd use an A7R.
Hopefully, Sony will be as good at implementing significant enhancements through firmware updates as Fujfilm has been.
p.98 #4 · Sony A7 and A7r Full Frame with Canon Lenses
While no camera is perfect, it depends on how much the foibles impact your style of shooting. I absolutely love my a7R. The resolution is stunning (it won't matter much though to those that are happy with the resolution and DR of the 5D III/6D.)
Here's a 100% crop:
http://www.devine.us/img/s5/v120/p416067118.jpg
From this photo:
http://www.devine.us/img/s5/v121/p216076125-5.jpg
Sorry I'm too lazy to mark the cropped area on the original photo, looking at the row of cars parked across the lower third of the frame, the crop is between the 3rd and 4th car counting from left to right.
p.98 #5 · Sony A7 and A7r Full Frame with Canon Lenses
Hey Tim, that looks great. I'm still very interested in the A7R, but I'd prefer an electronic first curtain. I'll probably wait to see what the Mk II version looks like, unless I find an offer that I can't refuse.
p.98 #6 · Sony A7 and A7r Full Frame with Canon Lenses
Understood....would love if it had EFCS, but most of my shooting is on the wide end....so it's less of a concern for me. I hope they keep building out the FF mirrorless line, they are off to a very good start. The 35 FE and especially the 55 FE are stunning. Sold off my Sigma 35 in EF mount to help fund the 35/55 FE purchase. I don't need speed at 35, it's better served for me at 55.
That leaves me with 15 ZE, 21 ZE, 28 f/2.8 IS and some other EF lenses that I can use on my 5D II and the a7R adapted.
p.98 #8 · Sony A7 and A7r Full Frame with Canon Lenses
marc aurel wrote: A7R+TS-E 24: Internal reflections in Metabones III adapter and what could help - Part 2: how to do it
The geometry of the adapter is not very simple, so it's a bit tricky to do. Below are images of how it looks after the modification.
I made a cutting pattern which consists of several perts (see below). It's not absolutely precise, but it worked well. The jpg with the cutting pattern is scaled 1:1, so you could use it to try. Your own risk of course... ubt the self-adhesive velour i used could be removed without problems.
At first I covered every surface inside. Then I noticed that at a shift of more than 10mm the velours interfered with the optical beam path (the opening of the adapter is just about 36x24mm). When shifted up (rise), the lowest part of the image bottom went darker. When shifting down (fall), it went darker on top.
So I took off the velour on one surface (marked green in the cutting pattern), but only the one that interfered with the shift up (cause i don't use more than 10mm of shift down). The problem was gone and it didn't visibly change the image quality. Either this was not the problematic surface, or it is sufficient to treat most of the surfaces to prevent a ping-pong-effect of reflections. Image 2 shows how that looks. You can also see that - despite of the matte black finishing - the metal does reflect.
Maybe it's not to everyones taste do such things - but now i get the best image quality available for this sensor size when shift is needed.
I can do full shift (-12mm to 12mm) without any vignette. I also used all Marc's pieces (Top, bottom, left side, right side, and front)
From my tests today, all issues with reflection/corner diffraction are now fixed.
I got an email from Novoflex and they are developing an adapter for EOS-Full E-Mount. Here is what they wrote:
"Dear Fred,
we are working on a better solution, Metabones offers at the moment.
That will take us 3 to 5 more months, between March - June"
p.98 #9 · Sony A7 and A7r Full Frame with Canon Lenses
Hi Fred,
I am glad to hear that your TSE lens performs as it should now. I ordered similar flocking material from another vendor but I have not received it yet.
Just an update, the RJC adapter doesn't work as it should/advertised. Using two different copies of RJC adapters revealed smearing on the left side using wide angle lenses . I am in contact with them and told them about the problems I encountered. They are in the process of looking into that issue. My Metabones will be delivered tomorrow.
Novoflex is working on a new adapter, huh? Interesting! Knowing their pricing though, it won't be inexpensive.... probably approximately $600 .
p.98 #14 · Sony A7 and A7r Full Frame with Canon Lenses
I am curious if those who taped their adapter will notice an increased amount of dirt on the sensor.
Since the shutter of the A7R is open on default it could cause problems if the velour paper is made of poor quality.
Just ordered some paper and decided that i will not use it because the fiber material peels off easily.
p.98 #16 · Sony A7 and A7r Full Frame with Canon Lenses
Achim Sieger wrote:
I am curious if those who taped their adapter will notice an increased amount of dirt on the sensor.
Since the shutter of the A7R is open on default it could cause problems if the velour paper is made of poor quality.
Just ordered some paper and decided that i will not use it because the fiber material peels off easily.
Anybody there who has made some experience?
Best regards
Achim
Achim,
If it peels off, do not use it. It will end up on your sensor. Not a huge deal though, you just have to clean it.
That is why I recommend back flock paper. The fibers are very small and will not come off. It's the same paper Canon use on their TS-E lenses.
Fred
p.98 #17 · Sony A7 and A7r Full Frame with Canon Lenses
Visibly peeling off is one thing but if the material breaks apart and leaving minute particles that can clutter the sensor is what worries more than anything else. But if lenses manufacturers use it then, it should be OK. I guess time will tell then....
p.98 #18 · Sony A7 and A7r Full Frame with Canon Lenses
I just got the Markins L-Bracket LS-A7 for the A7R.
FYI: It's well made and slim. Fits the body perfectly. I may just keep it on the camera at all times.
