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Check this out: a7R (in crop mode) vs NEX-5N [C Biogon 21mm]
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PostPosted: Sun Dec 22, 2013 12:49 pm    Post subject: Check this out: a7R (in crop mode) vs NEX-5N [C Biogon 21mm] Reply with quote
This is very interesting.
I knew my C Biogon has awful corners on the a7R.

OK. Let's try it in crop mode. I would expect similar results to my NEX-5N.
Well. See below...
(in-camera JPEGS, 100% crops of the bottom left corner, lens wide-open)


NEX-5N



a7R



WTF?
This is not much better that operating the camera in FF mode.
I would really like to hear what Sony has to say about this.


PostPosted: Sun Dec 22, 2013 1:44 pm    Post subject: Reply with quote
Maybe they built in some room for improvement for future models.


PostPosted: Sun Dec 22, 2013 2:09 pm    Post subject: Reply with quote
The thing is why should Sony care about how well the A7R performs with the Biogon?
Yes, many of us are amazed by the A7-series because we get "full frame" for all our manual lenses. But Sony still wants to sell lenses, their own ones.

BTW, the A7 (withouth the "R") is condidered to be better with adapted lenses.


PostPosted: Sun Dec 22, 2013 2:43 pm    Post subject: Reply with quote
LucisPictor wrote:
The thing is why should Sony care about how well the A7R performs with the Biogon?
Yes, many of us are amazed by the A7-series because we get "full frame" for all our manual lenses. But Sony still wants to sell lenses, their own ones.

BTW, the A7 (withouth the "R") is condidered to be better with adapted lenses.


1. We care here. Don't you find this information interesting for our forum?
2. Apparently Sony cared for our manual lenses in their NEX series
3. If Sony wants to sell lenses, they should better bring a few on the market!


PostPosted: Sun Dec 22, 2013 4:59 pm    Post subject: Reply with quote
Well, Nikos, either your camera exemplar is faulty, and then they should replace it for you (since it's new),
or, the A7r has a serious image quality issue.
Given that, I think, other people would have already found that, if that was a model design failure, I tend to think
that it's more likely that you may have received a faulty camera exemplar Sad
Carsten, the image degradation in the A7r sample shown here is so blatant, that it's impossible to be justified with an
argument such as that the A7r does worse with manual lenses than the A7. "Worse" is no replacement word for "awful".


PostPosted: Sun Dec 22, 2013 6:46 pm    Post subject: Reply with quote
The question are:

1. Was this on a tripod?
2. What was the shutter speed?
(around 1/100 the A7r seems to have a shake problem)
3. Is this reproducible?


PostPosted: Sun Dec 22, 2013 7:13 pm    Post subject: Reply with quote
blende8 wrote:
The question are:

1. Was this on a tripod?
2. What was the shutter speed?
(around 1/100 the A7r seems to have a shake problem)
3. Is this reproducible?


This was not on tripod, but shutter speed was 1/2000.

Anyway, I 've just done some indoor testing on a tripod.
I put a resolution chart in the corner of the frame.

I could not reproduce the issue with the kit lens of NEX-5N, or with Zeiss Variosonnar 35-70 C/Y.
If you try hard enough, you could say that the Biogon 2/35 ZM is a bit better on the NEX-5N.

I will try to reproduce the results I got in the morning with the 21mm Biogon, but it seems it has to do with lens design.
Although I cannot understand it.

EDIT:
I did again the test with the C Biogon.
Although the C Biogon is a still better on the NEX, especially regarding vignetting, the outcome is not as tragic as the one I saw in the morning.
Perhaps it was a focus issue.
I noticed that while focusing on the same target, the distance scale mark ends up in quite a different position on each camera (isn't this strange?) .


nex-5n



a7r


PostPosted: Sun Dec 22, 2013 7:59 pm    Post subject: Reply with quote
Nikos wrote:
1. We care here. Don't you find this information interesting for our forum?

Nikos, no offence. Of course, we care and I definitely do think that this is an interesting post!
I just wanted to change perspective a little. We, as adapter fans, are a rather small part of the photographic society. Wink

Nikos wrote:

3. If Sony wants to sell lenses, they should better bring a few on the market!

That's right. I agree.


PostPosted: Sun Dec 22, 2013 8:01 pm    Post subject: Reply with quote
Orio wrote:
Well, Nikos, either your camera exemplar is faulty, and then they should replace it for you (since it's new),
or, the A7r has a serious image quality issue.
Given that, I think, other people would have already found that, if that was a model design failure, I tend to think
that it's more likely that you may have received a faulty camera exemplar Sad

Nikos should test that with an original Sony APS lens.


Orio wrote:

Carsten, the image degradation in the A7r sample shown here is so blatant, that it's impossible to be justified with an
argument such as that the A7r does worse with manual lenses than the A7. "Worse" is no replacement word for "awful".

You're right, but as long as effects like this one do not happen with Sony lenses, I'm sure Sony doesn't care. Sad


PostPosted: Sun Dec 22, 2013 8:11 pm    Post subject: Reply with quote
LucisPictor wrote:
Orio wrote:
Well, Nikos, either your camera exemplar is faulty, and then they should replace it for you (since it's new),
or, the A7r has a serious image quality issue.
Given that, I think, other people would have already found that, if that was a model design failure, I tend to think
that it's more likely that you may have received a faulty camera exemplar Sad

Nikos should test that with an original Sony APS lens.


Orio wrote:

Carsten, the image degradation in the A7r sample shown here is so blatant, that it's impossible to be justified with an
argument such as that the A7r does worse with manual lenses than the A7. "Worse" is no replacement word for "awful".

You're right, but as long as effects like this one do not happen with Sony lenses, I'm sure Sony doesn't care. Sad


Carsten, I did check with the Sony kit lens from NEX-5N. See my post above.

It seems that the C Biogon produces extreme field curvature on a7R.
I set the camera parallel to a wall.
To focus in the middle, I focused at 1.5m (lens-scale).
To focus near the edge, I focused at 1m.

It is like shooting a projection on a spherical surface...


PostPosted: Mon Dec 23, 2013 11:37 am    Post subject: Reply with quote
Nikos wrote:
2. Apparently Sony cared for our manual lenses in their NEX series


I don't remember Sony selling us adapters for this purpose Wink

I'm sure this is a sensor design thing, and the a7r will be great with Sony E mount lenses. I'm 100% sure Sony didn't design this camera for people wanting use rf lenses on it!


PostPosted: Tue Dec 24, 2013 12:25 pm    Post subject: Reply with quote
there is something that I don't understand.
If you set your subject in the corner of the frame once with the nex and once with A7 , you are testing your lens not your sensor.
Is that lens a FF lens?
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