FAQ FAQ  Forum Search   Events   Register Register  Login Login

Sony 85mm F2.8 SAM Prime Comparison to Zooms

Page  12>
Author
QuietOC View Drop Down
Senior Member
Senior Member

Joined: 28 February 2015
Country: United States
Location: Michigan
Status: Offline
Posts: 3681
Post Options Post Options   Quote QuietOC Quote  Post ReplyReply Direct Link To This Post Topic: Sony 85mm F2.8 SAM Prime Comparison to Zooms
    Posted: 10 September 2016 at 16:10
Updating this using the A65 and the big new test chart and more lenses.

Tamron SP 60mm F2 @ ~85mm f/2.8 on a Kenko DGX 1.4X TC

Just a little wider than the SAL85F28

Minolta AF 24-85mm F3.5-4.5 @ 85mm f/4.5

Internal focus zoom is quite a bit wider

Sony 16-80mm f/3.5-4.5 Carl Zeiss Vario-Sonnar T DT @ 80 mm

A little wider than the Minolta above, but it doesn't claim to reach 85mm.

f/2.8 Center


f/2.8 Top Left


f/2.8 Bottom Right


You can use the shorter/faster primes on a teleconverter, but the results are rather mediocre.

f/4, f/4.5, f/5 Center


f/4, f/4.5, f/5 Top Left


f/4, f/4.5, f/5 Bottom Right


f/5.6 Center



f/5.6 Top Left



f/5.6 Bottom Right



f/8 Center



f/8 Top Left



f/8 Bottom Right



The Sony DT 55-200mm F4-5.6 SAM and Minolta AF 28-105 F3.5-4.5 look similarly decentered.

Edited by QuietOC - 10 September 2016 at 20:58
Sony A7RIV LA-EA5
Pentax Q7 5-15 15-45/2.8 8.5/1.9 11.5/9
 



Back to Top
Miranda F View Drop Down
Senior Member
Senior Member

Joined: 11 January 2014
Country: United Kingdom
Location: Bristol
Status: Offline
Posts: 4074
Post Options Post Options   Quote Miranda F Quote  Post ReplyReply Direct Link To This Post Posted: 25 June 2016 at 06:54
These differences are only obvious at 100% crop, right? I wouldn;t normally use 100% crops except for birding, though I do habitually check pictures after taking with the 100% crop view function in the EVF to check they were focussed correctly. Most of my pictures with the dt zooms do look sharp then, and if they don't I usually re-take them.

But they are so sharp (in the centre, at least) that the slightest mis-focus will affect this, which makes their effective DOF much smaller than you would expect for that aperture, when you check them this way. I suppose I'm saying that they maintain a high micro-contrast well up to the limits of the sensor.
Miranda F & Sensorex, Sony A7Rii, A58, Nex-6, Dynax 4, 5, 60, 500si/600si/700si/800si, various Sony & Minolta lenses, several Tamrons, lots of MF primes and *far* too many old film cameras ...
Back to Top
Miranda F View Drop Down
Senior Member
Senior Member

Joined: 11 January 2014
Country: United Kingdom
Location: Bristol
Status: Offline
Posts: 4074
Post Options Post Options   Quote Miranda F Quote  Post ReplyReply Direct Link To This Post Posted: 25 June 2016 at 06:49
Originally posted by addy landzaat addy landzaat wrote:

At what focus distance? The more experienced I get I find that focus distance is very important. Some lenses are great at longer distances but lousy at MFD and the other way round.


+1
Miranda F & Sensorex, Sony A7Rii, A58, Nex-6, Dynax 4, 5, 60, 500si/600si/700si/800si, various Sony & Minolta lenses, several Tamrons, lots of MF primes and *far* too many old film cameras ...
Back to Top
QuietOC View Drop Down
Senior Member
Senior Member

Joined: 28 February 2015
Country: United States
Location: Michigan
Status: Offline
Posts: 3681
Post Options Post Options   Quote QuietOC Quote  Post ReplyReply Direct Link To This Post Posted: 24 June 2016 at 18:01
Originally posted by addy landzaat addy landzaat wrote:

On other lenses there is a significant difference between MFD, Mid distances and infinity.

I am curious. What other lenses specifically?

The 100-200 F4.5 and 28-135 F4-4.5 are two I've tested at much greater distances because they seem to perform relatively poorly on the test chart, and they have a reputation for being sharp. This 28-135 actually looks fairly good in this test.
Sony A7RIV LA-EA5
Pentax Q7 5-15 15-45/2.8 8.5/1.9 11.5/9
Back to Top
addy landzaat View Drop Down
Senior Member
Senior Member

Joined: 22 April 2006
Country: Netherlands
Location: Netherlands
Status: Offline
Posts: 15198
Post Options Post Options   Quote addy landzaat Quote  Post ReplyReply Direct Link To This Post Posted: 24 June 2016 at 17:36
On other lenses there is a significant difference between MFD, Mid distances and infinity.
Why not follow me on Instagram? @Addy_101
Back to Top
QuietOC View Drop Down
Senior Member
Senior Member

Joined: 28 February 2015
Country: United States
Location: Michigan
Status: Offline
Posts: 3681
Post Options Post Options   Quote QuietOC Quote  Post ReplyReply Direct Link To This Post Posted: 24 June 2016 at 16:37
This was pretty close. As I said above it was near the minimum focus distance of the 1985 Minolta AF 35-105 F3.5-5.6 ~1.5m.

The distance might matter, but I have gotten similar results at greater distances too. I've done some comparisons recently outdoors with a brick wall. I did a comparison last year with a large horse statue.

My main goal here was just to see if the new 85/2.8 was any better than the old one, and the answer is, no.
Sony A7RIV LA-EA5
Pentax Q7 5-15 15-45/2.8 8.5/1.9 11.5/9
 



Back to Top
addy landzaat View Drop Down
Senior Member
Senior Member

Joined: 22 April 2006
Country: Netherlands
Location: Netherlands
Status: Offline
Posts: 15198
Post Options Post Options   Quote addy landzaat Quote  Post ReplyReply Direct Link To This Post Posted: 24 June 2016 at 15:58
At what focus distance? The more experienced I get I find that focus distance is very important. Some lenses are great at longer distances but lousy at MFD and the other way round.
Why not follow me on Instagram? @Addy_101
Back to Top
craig66 View Drop Down
Senior Member
Senior Member

Joined: 03 April 2012
Country: Australia
Status: Offline
Posts: 637
Post Options Post Options   Quote craig66 Quote  Post ReplyReply Direct Link To This Post Posted: 24 June 2016 at 15:32
My copy of the 35-105 (orig) is sharper in the corners than the 55-300 DT at wider apertures. It also has much less off-axis astigmatism. The 55-300 is sharper in the centre but not by a large margin.

My only other DT zoom - the 16-50 f2.8 SSM - is an astigmatism monster at the long end. It also has considerable focus shift at the long end.

The problem with lens tests is the sample variation.
Back to Top
thornburg View Drop Down
Senior Member
Senior Member

Joined: 25 July 2013
Country: United States
Location: PA
Status: Offline
Posts: 3765
Post Options Post Options   Quote thornburg Quote  Post ReplyReply Direct Link To This Post Posted: 24 June 2016 at 14:27
Originally posted by QuietOC QuietOC wrote:

I do a lot of these comparisons. This isn't odd performance for the 24-85. It would look a lot better compared over its entire range with some other normal zooms instead of trying to match a prime and the telephoto zooms at 85 mm.


Maybe I had a much better than average copy.

I mostly shot with it at 85, which is was my original rational for letting it go -- since I was only using the long end, other zooms, like the 35-105, made more sense (that, and a forum member made me a very good offer on it).
Sony a3000, a6000, a57, a99 - Sony E 16-50, 28/2 | Vivitar 13, 85 | Minolta 24, 28-105, 35-105, 50/1.7, 75-300 | Tokina 28-70/2.6-2.8 | Sigma 70/2.8 Macro | Tamron 70-200/2.8 | Celestron 1000/11
Back to Top
QuietOC View Drop Down
Senior Member
Senior Member

Joined: 28 February 2015
Country: United States
Location: Michigan
Status: Offline
Posts: 3681
Post Options Post Options   Quote QuietOC Quote  Post ReplyReply Direct Link To This Post Posted: 24 June 2016 at 14:05
I used a tripod. Steady Shot off. I frame the chart with the prime and then keep the tripod in that location for all the other lenses. I focused the 55-200 and 55-300 twice which is why there are two photos of those.

These are all very good copies of these lenses. Well the 28-135 is pretty sad looking and doesn't focus at infinity right now. Remember the zooms here are all wide-open. I just tried another copy of the original 35-105 that was worse than this copy. I am surprised by how badly that lens did in this comparison. The chart might be a little closer than the MFD of the 35-105. That is not an issue for the 24-85 though.

I believe this is the sharpest 24-85 I've had. It is the third one. Performance at the 85 mm end is not its strength. I know the 28-105s were a lot sharper at 85 mm than the previous copies of the 24-85. The 85 mm end of the 24-85 does not match the field-of-view of the 85/2.8 here either. The 85/2.8 is a bit longer than 85 mm at this distance, and the 24-85 is shorter than 85 mm at this distance.

I do a lot of these comparisons. This isn't odd performance for the 24-85. It would look a lot better compared over its entire range with some other normal zooms instead of trying to match a prime and the telephoto zooms at 85 mm.
Sony A7RIV LA-EA5
Pentax Q7 5-15 15-45/2.8 8.5/1.9 11.5/9
Back to Top
thornburg View Drop Down
Senior Member
Senior Member

Joined: 25 July 2013
Country: United States
Location: PA
Status: Offline
Posts: 3765
Post Options Post Options   Quote thornburg Quote  Post ReplyReply Direct Link To This Post Posted: 24 June 2016 at 13:20
Did you take several shots with each lens and only use the best one?
Did you use a tripod?

It seems to me that some of your results are so blurry that there was either a flaw in the shot (camera shake, missed focus, etc), or you have a very poor copy of that lens.

For example, my first copy of the 24-85 was much sharper than your results here.

I haven't tested my current copy to the same extent, as I rarely use it.
Sony a3000, a6000, a57, a99 - Sony E 16-50, 28/2 | Vivitar 13, 85 | Minolta 24, 28-105, 35-105, 50/1.7, 75-300 | Tokina 28-70/2.6-2.8 | Sigma 70/2.8 Macro | Tamron 70-200/2.8 | Celestron 1000/11
Back to Top
QuietOC View Drop Down
Senior Member
Senior Member

Joined: 28 February 2015
Country: United States
Location: Michigan
Status: Offline
Posts: 3681
Post Options Post Options   Quote QuietOC Quote  Post ReplyReply Direct Link To This Post Posted: 24 June 2016 at 11:34
The more corrected lenses like the 18-135 and 55-300 are sharp in the center even with the focus off quite a bit. The ones with axial CA there is basically a choice between minimizing fringing or maximizing sharpness or somepoint between those. They just can't get very sharp.

A flat focus plane is not important for most photos.
Sony A7RIV LA-EA5
Pentax Q7 5-15 15-45/2.8 8.5/1.9 11.5/9
Back to Top
Miranda F View Drop Down
Senior Member
Senior Member

Joined: 11 January 2014
Country: United Kingdom
Location: Bristol
Status: Offline
Posts: 4074
Post Options Post Options   Quote Miranda F Quote  Post ReplyReply Direct Link To This Post Posted: 24 June 2016 at 07:21
Interesting!
It seems to confirm my experience that the dt zooms are extremely sharp in the centre when you can get them focussed well enough, even near full aperture, though focussing them accurately enough in real life is often non-trivial (the A58 AF certainly isn't good enough).
The corners look good too on my phone screen, how do they look to you?
Miranda F & Sensorex, Sony A7Rii, A58, Nex-6, Dynax 4, 5, 60, 500si/600si/700si/800si, various Sony & Minolta lenses, several Tamrons, lots of MF primes and *far* too many old film cameras ...
Back to Top
QuietOC View Drop Down
Senior Member
Senior Member

Joined: 28 February 2015
Country: United States
Location: Michigan
Status: Offline
Posts: 3681
Post Options Post Options   Quote QuietOC Quote  Post ReplyReply Direct Link To This Post Posted: 24 June 2016 at 02:48
The two 85/2.8s are focused at different points. I can tell by the axial CA. The left one is showing more magenta in the center. Magenta fringing showing in the center tends to look sharper than cyan fringing showing. The focus plane is a bit curved so that one also ends up with more in-focus corners.
Sony A7RIV LA-EA5
Pentax Q7 5-15 15-45/2.8 8.5/1.9 11.5/9
Back to Top
Dyxum main page >  Forum Home > Equipment forums > Lens Talk > A-mount lenses Page  12>

Forum Jump Forum Permissions View Drop Down



This page was generated in 0.094 seconds.

Monitor calibration strip

Dyxum.com - Home of the alpha system photographer

In memory of Cameron Hill - brettania

Feel free to contact us if needed.