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08-15-2014, 11:04 AM   #16
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QuoteOriginally posted by osv Quote
that is not correct.

the only adapters you should be using don't have any glass, so of course they can't alter the optical properties of the lenses.
That would be true if the adapter were perfectly aligned, perfectly planed and precisely the right depth. Unfortunately you don't get that with a $20 adapter. The ones I own have considerable slop when mounted, it is easy to rock the lens assembly back and forth. That does not inspire confidence in the machining.

I have to say though, in looking at my results from a test today, K-3 vs a6000 + adapter, the statement I made above is exaggerated. There is an optical compromise with an adapter, but it is not as big a deal as I made it sound. My apology. I wasn't just trying to be dramatic, I was looking at some test photos I shot yesterday with three adapters and my smc A 135mm. I don't use that lens much and my reaction was mostly due to the lens characteristics wide open, and much less to do with the adapters.

Lenstip did a piece where they tested a bunch of adapters and found compromised resolution, but I couldn't locate it. All I could find was this reference to the article.

"The second reason is the build quality of those adapters. Very often they are responsible for slanting the optical axis of a lens to a wrong angle which results in errors. It is not my imagination that fact was confirmed by testing initially several of such adapters."
Carl Zeiss Makro-Planar T* 50 mm f/2 ZF/ZK/ZE review - Image resolution - Lenstip.com


Last edited by audiobomber; 08-15-2014 at 11:19 AM.
08-15-2014, 01:02 PM   #17
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QuoteOriginally posted by audiobomber Quote
"The second reason is the build quality of those adapters. Very often they are responsible for slanting the optical axis of a lens to a wrong angle which results in errors. It is not my imagination that fact was confirmed by testing initially several of such adapters."
That's well understood by those of us who use scopes it's called "decollimation"

-------------------------------------
Collimation

"Collimation" refers to all the optical elements in an instrument being on their designed optical axis. It also refers to the process of adjusting an optical instrument so that all its elements are on that designed axes (in line and parallel). With regards to a telescope the term refers to the fact that the optical axes of each optical component should all be centered and parallel, so that collimated light emerges from the eyepiece."
------------------------------------

In your case instead of an eyepiece its a sensor.

---------- Post added 08-15-14 at 03:25 PM ----------

QuoteOriginally posted by audiobomber Quote
I don't know if you're referring to something I said.
Not really - I was referring to the general inclination many people seem to have of taking a nice handy small camera and turning into yet another bloated, clumsy beast that's neither well suited at normal nor long focal lengths.

Last edited by wildman; 08-15-2014 at 01:28 PM.
08-15-2014, 02:40 PM   #18
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QuoteOriginally posted by Christine Tham Quote
The old kit zoom that was sold with the original NEX is also very good (you may be able to find it on Ebay)
Is this what you are referring to?

Sony 18-55mm f/3.5-5.6 OSS E-mount NEX Series Camera Lens SEL1855
08-15-2014, 03:49 PM   #19
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QuoteOriginally posted by wildman Quote
Yes that's the one. Don't pay full price for it - you should be able to pick one up for a song from people who bought the original NEX3 or NEX5. I might even have a spare lying around.

Not a fast lens but very sharp and colourful. Great bokeh if you can get it through close focusing.

08-15-2014, 04:28 PM   #20
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If anyone has a good, clean used 55-210 in Australia, I'd be willing to make a fair offer.

Jason
08-15-2014, 06:06 PM   #21
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QuoteOriginally posted by audiobomber Quote
That would be true if the adapter were perfectly aligned, perfectly planed and precisely the right depth. Unfortunately you don't get that with a $20 adapter. The ones I own have considerable slop when mounted, it is easy to rock the lens assembly back and forth. That does not inspire confidence in the machining.
sounds like a loss of spring tension in the adapter, and it's easily fixed... you can make the lens mount so tight that you can barely screw the lens on.

it's probably the cheap adapters with the cut metal slits you are referring to... put a small screwdriver in the slit, and twist it slightly, opening up the slit... if you leave the lens mounted to the adapter, it probably won't lose tension.

there are a couple of references to lens tests, that claim that a "crooked" adapter lowers resolution... in a perfect lens test, the sensor is exactly parallel with lens, which is exactly parallel with the chart being shot... but when the lens is tilted slightly, it's out of alignment with the chart and the sensor... the focal plane is not parallel.

would anyone claim that the canon t/s 24mm lens loses resolution when it's tilted? probably not... but people are willing to claim that adapter-induced tilt can lower resolution, which is not logical.

---------- Post added 08-15-2014 at 06:17 PM ----------

QuoteOriginally posted by wildman Quote
That's well understood by those of us who use scopes it's called "decollimation"

-------------------------------------
Collimation

"Collimation" refers to all the optical elements in an instrument being on their designed optical axis. It also refers to the process of adjusting an optical instrument so that all its elements are on that designed axes (in line and parallel). With regards to a telescope the term refers to the fact that the optical axes of each optical component should all be centered and parallel, so that collimated light emerges from the eyepiece."
------------------------------------

In your case instead of an eyepiece its a sensor.
i don't think that is true.

"The third optical component in the telescope system is the eyepiece. It is a complex magnifying lens used to view the image formed at the focal plane. - See more at: How to Align Your Newtonian Reflector Telescope

the sensor doesn't do any magnifying at all, it's not part of any optical system.

Last edited by osv; 08-15-2014 at 06:18 PM.
08-15-2014, 07:30 PM   #22
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QuoteOriginally posted by osv Quote
i don't think that is true.
Neither do I - I was just trying to point out the rough analogy between a sensor in a camera and the human eye when viewing through a scope.
I thought it would be helpful but perhaps not.
08-17-2014, 04:43 AM   #23
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Ok pulled the trigger on this;

a6000 $650
used original 18-55 kit in ex. condition $110
used Sigma 60mm f/2.8 $120
A few other misc odds and ends.

Done.

08-17-2014, 05:18 AM   #24
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QuoteOriginally posted by wildman Quote
Ok pulled the trigger on this;

a6000 $650
used original 18-55 kit in ex. condition $110
used Sigma 60mm f/2.8 $120
A few other misc odds and ends..
Congrats, let us know what you think. I am particularly interested in your view of the Sigma 60mm as a portrait lens, if you wouldn't mind. It seems to be quite the performer wide open.
08-17-2014, 06:24 AM   #25
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QuoteOriginally posted by audiobomber Quote
I am particularly interested in your view of the Sigma 60mm
So am I - when I have the 18-250mm zoom mounted on the K5 and take test shots I've found that what I consider "normal" FL to my eye is between 50-60mm for some reason - so the Sigma might very well end up being my primary working glass on the a6000. I just wish it was stabilized.

Will keep you posted.

Last edited by wildman; 08-17-2014 at 07:00 AM.
08-17-2014, 07:52 AM   #26
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QuoteOriginally posted by wildman Quote
So am I - when I have the 18-250mm zoom mounted on the K5 and take test shots I've found that what I consider "normal" FL to my eye is between 50-60mm for some reason - so the Sigma might very well end up being my primary working glass on the a6000.
I just wish it was stabilized.
OSS is a nice feature for sure. I read this morning in DPR forum that the Sigma lenses do not support phase-detect focus. The Zeiss Touits cannot use PDAF either, but Zeiss has said this will be added in firmware shortly.

I just tested focus capabilities with the Zeiss12mm vs. Sony 16-50. The Zeiss does not allow Wide or Zone focus in AF-C, therefore will not track, and cannot use AF Lock. I think I'll need this feature for my short tele, so I'm crossing the Sigma 60mm off my list. You will need to update firmware to enable PDAF on the 18-55, if it hasn't been updated previously.

Henry's has a sale on the Sony 50mm 1.8. Tempting, but 50mm is still not what I want.
SONY SEL 50MM F1.8 OSS LENS BLACK SEL50F18B

PS You will want to download this a6000 Help Guide. The "manual" that comes with the a6000 is very thin.
http://www.google.ca/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CBwQFjAA&...uY0aiX3sFz29hw
I found the a6000 review at DPR quite helpful in configuring the camera.
08-17-2014, 09:39 AM   #27
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QuoteOriginally posted by Jasvox Quote
clean used 55-210 in Australia
DCW have it available new for $190 at the moment ...
08-18-2014, 11:59 AM   #28
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QuoteOriginally posted by audiobomber Quote
OSS is a nice feature for sure. I read this morning in DPR forum that the Sigma lenses do not support phase-detect focus. The Zeiss Touits cannot use PDAF either, but Zeiss has said this will be added in firmware shortly.
I had some misinformation. It seems the Sigma DN and Zeiss Touit lenses do read PDAF, but only in the center focal zone. What I said yesterday appears to be correct; Wide and Zone focus are not available in AF-C, therefore will not track, and cannot use AF Lock.
09-05-2014, 11:09 AM   #29
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QuoteOriginally posted by wildman Quote
So am I - when I have the 18-250mm zoom mounted on the K5 and take test shots I've found that what I consider "normal" FL to my eye is between 50-60mm for some reason - so the Sigma might very well end up being my primary working glass on the a6000. I just wish it was stabilized.

Will keep you posted.
I keep coming back to the Sigma 60mm to complete my kit. It's small enough that I can carry it in my small messenger back with two other lenses, it's the longest prime available for E-mount, the cost is ideal, and sharper with less CA than the SEL50F18. But how do you like it? How is it for portraits at f2.8?

Last edited by audiobomber; 09-05-2014 at 12:31 PM.
09-05-2014, 11:41 PM - 1 Like   #30
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QuoteOriginally posted by audiobomber Quote
I keep coming back to the Sigma 60mm to complete my kit. It's small enough that I can carry it in my small messenger back with two other lenses, it's the longest prime available for E-mount, the cost is ideal, and sharper with less CA than the SEL50F18. But how do you like it? How is it for portraits at f2.8?
Highly recommending sigma 60 as a good prime for the E mount. I purchased Sigma 60 after happy ownership with Sony E 50mm f/1.8 and I have no regrets in the purchase. The Sigma 19, 30 and 60 are the best value trinity set for E mount.




















wide open in f/2.8 in iso 3200 with 5N


I don't recommend using Sigma 60mm f/2.8 on FE mount but I sometime use it in a pinch and post-process on the vignette








Blog posts on Sigma 60: Hin's Photo Corner: Sigma 60mm f/2.8

Cheers,
Hin
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