p.3 #3 · DXOMark: Sony FE 24-70/2.8 GM - Best zoom in the range
dccb2009 wrote:
Isn't the A7R known to have shutter shake, which could potentially affect the resolution score?
I'm not sure why they haven't used A7RII for their Sony testing platform yet.
The vibration issue with the A7r cameras was generally for lenses about 100mm and longer with a shutter speed of about 1/100 to 1/15 second. This problem can be worked around if you use some care and ways of mitigating the issue.
p.3 #4 · DXOMark: Sony FE 24-70/2.8 GM - Best zoom in the range
Yes it does have shutter shake and yes it's a possibility it could effect the scores but it's going depend on what shutter speeds they used also focal length( longer focal lengths adds to the problem).Which I don't follow how they test. These tests should have been done with the A7rII and use adapters for using Canon, Nikon lenses on exactly the same body. Otherwise you throwing tons of variables in the mix. Testing should be done with the least amount of variables when shooting same with processing the files. That's the ideal way to do things plus tripods, timer delays and all the best techniques used to run tests. My problem is as someone that runs tests in real world , I'm not ever sure how they set these up or processing so I'm always gun shy on believing them. I trust very few folks doing tests. I like what Roger does at lens rentals and obviously Fred and some other members but I'm more apt to run them myself. I do trust myself.
p.3 #5 · DXOMark: Sony FE 24-70/2.8 GM - Best zoom in the range
naturephoto1 wrote:
The vibration issue with the A7r cameras was generally for lenses about 100mm and longer with a shutter speed of about 1/100 to 1/15 second. This problem can be worked around if you use some care and ways of mitigating the issue.
Rich
The shutter shake reallly impacts the smooth reflections app. That's where I notice it the most.
Chris
p.3 #7 · DXOMark: Sony FE 24-70/2.8 GM - Best zoom in the range
dxo mark needs to update scores with a proper A7rii, the A7r cannot be trusted. Other than that, Dxo mark is by far the best resource in general. Their coverage is much larger than anyone else, and the field maps is what you want to stick to rather than the scores, which are more like headlines.
p.3 #8 · DXOMark: Sony FE 24-70/2.8 GM - Best zoom in the range
Charlie N wrote:
dxo mark needs to update scores with a proper A7rii, the A7r cannot be trusted. Other than that, Dxo mark is by far the best resource in general. Their coverage is much larger than anyone else, and the field maps is what you want to stick to rather than the scores, which are more like headlines.
Look how Zeiss test their cine glass, and how extremely thorough their testing methodology is. I have serious doubts about DXO's tests with cameras mounted on Cambo stands in makeshift studios offering little of anything other than anecdotal value. I'll take Lens Rentals optical bench tests using multiple copies any day.
p.3 #9 · DXOMark: Sony FE 24-70/2.8 GM - Best zoom in the range
Same here.
chrisgibbs wrote:
Look how Zeiss test their cine glass, and how extremely thorough their testing methodology is. I have serious doubts about DXO's tests with cameras mounted on Cambo stands in makeshift studios offering little of anything other than anecdotal value. I'll take Lens Rentals optical bench tests using multiple copies any day.
p.3 #11 · DXOMark: Sony FE 24-70/2.8 GM - Best zoom in the range
chrisgibbs wrote:
Look how Zeiss test their cine glass, and how extremely thorough their testing methodology is. I have serious doubts about DXO's tests with cameras mounted on Cambo stands in makeshift studios offering little of anything other than anecdotal value. I'll take Lens Rentals optical bench tests using multiple copies any day.
p.3 #13 · DXOMark: Sony FE 24-70/2.8 GM - Best zoom in the range
IMO, the problem with DXO lens test is not inconsistency, but those numbers can't tell much about the characteristics of a lens. Some lenses perform better at infinity, some are better at shorter distances (I usually don't care much about corner sharpness when shooting at, or close to infinity, unless I shoot macro of flat objects). Those numbers also tell nothing about coma and astigmatism (rather important for occasional astro shots, so I like lenstips tests for including that), flare, field curvature. So I really appreciate those real-life landscape lens test by Fred and other members here.
One thing I don't quite understand in DXO lens test is why T-stops in DXO can match f-stops of the lens?
DXO sensor scores, on the other hand, is more valuable since measurements for bodies I have used reflex my personal experience so I expect those numbers also representing those bodies I have never used, with fair accuracy. Sensor characteristics is much simpler than those of a lens, I suppose.
p.3 #14 · DXOMark: Sony FE 24-70/2.8 GM - Best zoom in the range
ytwong wrote:
IMO, the problem with DXO lens test is not inconsistency, but those numbers can't tell much about the characteristics of a lens. Some lenses perform better at infinity, some are better at shorter distances (I usually don't care much about corner sharpness when shooting at, or close to infinity, unless I shoot macro of flat objects). Those numbers also tell nothing about coma and astigmatism (rather important for occasional astro shots, so I like lenstips tests for including that), flare, field curvature. So I really appreciate those real-life landscape lens test by Fred and other members here.
One thing I don't quite understand in DXO lens test is why T-stops in DXO can match f-stops of the lens?
DXO sensor scores, on the other hand, is more valuable since measurements for bodies I have used reflex my personal experience so I expect those numbers also representing those bodies I have never used, with fair accuracy. Sensor characteristics is much simpler than those of a lens, I suppose. ...Show more →
F stop is a mathematical formula where as T stop is an actual measurement of light hitting sensor. The T stop is always less than f stop (there must be an example where I am wrong).
p.3 #15 · DXOMark: Sony FE 24-70/2.8 GM - Best zoom in the range
mogul wrote:
F stop is a mathematical formula where as T stop is an actual measurement of light hitting sensor. The T stop is always less than f stop (there must be an example where I am wrong).
That's basically what's in my mind about F and T stops, but DXO test often shows that a f2.8 lens have transmission of 2.8T. I thought T is always lower than f stop... like Cine version of a Zeiss 25mm f2 lens is T2.1.
p.3 #17 · DXOMark: Sony FE 24-70/2.8 GM - Best zoom in the range
Fred Miranda wrote:
Charlie,
You have to agree that for the very least, they should've used a current body for the test. The A7RII was announced more than a year ago!
Did your rental make it Fred? Really curious what you find.
p.3 #19 · DXOMark: Sony FE 24-70/2.8 GM - Best zoom in the range
I just did a few tests today and I have the impression that towards the long end, the Canon is sharper at the edges of the frame when compared to the GM (infinity distance).
I had forgotten how good the Canon was and it's even better on the A7RII. There is more CA on the Canon at wider apertures though. I am still checking and will post some samples soon. (BTW: I have 2 copies of the Canon)
Really curious what you find. 