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Archive 2013Some A7r Imatesting
p.1 #1Some A7r Imatesting
1st issue - remote won't trigger shutter when zoomed in at 7.2x or 14.4x.
The NEX7 and 5n did.
I use the magnification to get critical view then often remotely fire without retouching the system. It's a nit but one has to back out of the magnified views to full live view to trigger the shutter with a remote.
The plus - nice MTF centers. (about equal at 100 and 200 ISO) shutter was not an issue with 135mm APO and (undesired shutter speeds 1/125th shown and 1/160 not shown) ISO 50 may have been affected by shutter @ 1/60th. MTF was only 1380.
About to test 5 ROIs.
(sRGB -> LR5.3 -> no post (0) - output to ProPhoto RGB JPEG)
Edited on Dec 13, 2013 at 02:33 PM · View previous versions
The NEX7 and 5n did.
I use the magnification to get critical view then often remotely fire without retouching the system. It's a nit but one has to back out of the magnified views to full live view to trigger the shutter with a remote.
The plus - nice MTF centers. (about equal at 100 and 200 ISO) shutter was not an issue with 135mm APO and (undesired shutter speeds 1/125th shown and 1/160 not shown) ISO 50 may have been affected by shutter @ 1/60th. MTF was only 1380.
About to test 5 ROIs.
(sRGB -> LR5.3 -> no post (0) - output to ProPhoto RGB JPEG)
Edited on Dec 13, 2013 at 02:33 PM · View previous versions
Dec 13, 2013 at 11:10 AM
p.1 #3Some A7r Imatesting
Multi ROI testing isn't going well. As I've noted before, flange and sensor alignments are as critical to IQ as lens and camera choice. Of 5 Sony NEX7s tested 3 of them had bad corners. This A7r shows in both directions (variability between focus on BR vs Center and Center vs BR) that the bottom right corner of the sensor is mis-aligned to show a reduction of 50% in MTFs.
To isolate away from adapter (Novoflex) and a known good lens (Zeiss 135mm APO) the test was redone on a known good NEX7.
It's clear to see the NEX shoots flat (right) and there is a problem with the A7r (left) (In the example shown the BR appears higher because it was the critical focusing point) but in all tests with the Center (or R) as the focal point in this 2 ROI example the BR was appx 50% less than the center.)
(I've done some allowance for the differences in the FOV but not exact at this time. This may be just a case of 'uncharted lens territory)
To isolate away from adapter (Novoflex) and a known good lens (Zeiss 135mm APO) the test was redone on a known good NEX7.
It's clear to see the NEX shoots flat (right) and there is a problem with the A7r (left) (In the example shown the BR appears higher because it was the critical focusing point) but in all tests with the Center (or R) as the focal point in this 2 ROI example the BR was appx 50% less than the center.)
(I've done some allowance for the differences in the FOV but not exact at this time. This may be just a case of 'uncharted lens territory)
Dec 13, 2013 at 12:03 PM
p.1 #4Some A7r Imatesting
To make a more apples to apples comparison I set up the A7r and shot the MTF again. (The same ROIs and focus were used) Then with only swapping camera backs, I shot the NEX. Of course there may be some variance from the flange-sensor between the 2 cameras but there was some consistency to the prior observations. The NEX scores shown should not be taken as representative of the NEX7s capability as the focus wasn't done for that camera. Nevertheless, MTF comparisons are shown between the 2 cameras for this test. High ISO was used for the both to avoid the 1/160 and below shutter variable. I will reshoot the NEX with it optimized for this same shot.
The good news - the A7r is an incredible camera. I find it easy to critical focus (that extra 3x) and the EVF is better than the NEX in my use so far. Looking forward to night shooting. (I may or may not have a bad copy with this particular camera) Some field testing is in order as well as various other lens testing on Imatest.
Edited on Dec 13, 2013 at 01:58 PM · View previous versions
The good news - the A7r is an incredible camera. I find it easy to critical focus (that extra 3x) and the EVF is better than the NEX in my use so far. Looking forward to night shooting. (I may or may not have a bad copy with this particular camera) Some field testing is in order as well as various other lens testing on Imatest.
Edited on Dec 13, 2013 at 01:58 PM · View previous versions
Dec 13, 2013 at 01:21 PM
p.1 #5Some A7r Imatesting
The NEX7 reshot. Same ROIs tested as 'apples to apples'
As aligned as this users NEX7 is, the NEX7 doesn't resolve nearly as well as the A7r.
Me likey the A7r, but still in doubt if this one is a 'good copy'.
As aligned as this users NEX7 is, the NEX7 doesn't resolve nearly as well as the A7r.
Me likey the A7r, but still in doubt if this one is a 'good copy'.
Dec 13, 2013 at 01:51 PM
p.1 #7Some A7r Imatesting
A lot more Imatesting - the sensor appears to be aligned enough. The weak corners are random.
I was in a hurry to test some lenses and mainly focused on centers and at f5.6. It takes a lot of time to align 14mm-28mm lenses for Imatest and know you've done it right.
The main good news is that 'good lenses' will be great on the A7r. At the same time 2 lenses (yet to be named) that have performed very well on the NEX7 don't translate to stellar performance on the A7r.
Zeiss Varios that were tested (35-70, 28-85, 80-200) all did better at the short end. The 200mm on the 80-200 was really bad. Worse than a kit lens.
(These 'long end' problems may be shutter shake) I intend to retest in bright light and spend time trying to mitigate.
The 50 1.4 usually does better than the score being posted. Might be a bad test.
http://tinyurl.com/nymp58x (and older)
Edited on Dec 16, 2013 at 09:33 AM · View previous versions
I was in a hurry to test some lenses and mainly focused on centers and at f5.6. It takes a lot of time to align 14mm-28mm lenses for Imatest and know you've done it right.
The main good news is that 'good lenses' will be great on the A7r. At the same time 2 lenses (yet to be named) that have performed very well on the NEX7 don't translate to stellar performance on the A7r.
Zeiss Varios that were tested (35-70, 28-85, 80-200) all did better at the short end. The 200mm on the 80-200 was really bad. Worse than a kit lens.
(These 'long end' problems may be shutter shake) I intend to retest in bright light and spend time trying to mitigate.
The 50 1.4 usually does better than the score being posted. Might be a bad test.
http://tinyurl.com/nymp58x (and older)
Edited on Dec 16, 2013 at 09:33 AM · View previous versions
Dec 14, 2013 at 01:06 PM
p.1 #8Some A7r Imatesting
So what are you thoughts so far...keeping it or sending it back?
Dec 14, 2013 at 02:00 PM
p.1 #9Some A7r Imatesting
tsdevine wrote:
So what are you thoughts so far...keeping it or sending it back?
Not even a close call - keeping it. I've wanted FF almost since I got the NEX7 2 years ago which was my 1st camera that wasn't a PoS P&S.
I have a 'good lens' collection but this camera makes most of them 'great'.
The forefront concern I have now is how easy it will it be to keep the sensor clean and how will I fit the DustAid tools into the corners once it becomes necessary.
So what are you thoughts so far...keeping it or sending it back?
Not even a close call - keeping it. I've wanted FF almost since I got the NEX7 2 years ago which was my 1st camera that wasn't a PoS P&S.
I have a 'good lens' collection but this camera makes most of them 'great'.
The forefront concern I have now is how easy it will it be to keep the sensor clean and how will I fit the DustAid tools into the corners once it becomes necessary.
Dec 14, 2013 at 02:16 PM
p.1 #10Some A7r Imatesting
TSdevine - even with shutter blur on long lenses and the compression problem which now that I am aware of it also present on my NEX7 photos but not to the same degree I am keeping the camera. It takes great WA and B&W photos as long as there is lots of detail and complication in the composition.
Telephotos have two issues - more likely to blur but also more likely to generate smaller file sizes and more likely to show the compression issue in the 2nd iteration.
The Nikon 800 users in the forum state they haven't seen the artifacts in their photos but the liveview and EFV shortcomings are a non-starter for me with Nikon. I use MF almost 100% of the time.
Telephotos have two issues - more likely to blur but also more likely to generate smaller file sizes and more likely to show the compression issue in the 2nd iteration.
The Nikon 800 users in the forum state they haven't seen the artifacts in their photos but the liveview and EFV shortcomings are a non-starter for me with Nikon. I use MF almost 100% of the time.
Dec 16, 2013 at 09:38 AM