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Archive 2009 · Dispelling the Zeiss superiority myth?
  
 
Jonas B
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p.4 #1 · Dispelling the Zeiss superiority myth?


theSuede wrote:
I'm presently working in a project involving one of the founding persons behind the photodo measurements, I'll ask him how the weighed grade was calculated, if he's willing to disclose any details. AFAIK the lenses were measured with equipment similar to the optical reference instruments that Leica/Zeis Oberkochen use - not on film/digital that is. But I have no idea how sharpness/CA/center-edge and so on was weighed in the final number.


Interesting. I have this vague idea they (the Photodo guys) used an optical bench at Hasselblad, Gothenburg, for their lens tests.
But, however they did it, I'm pretty sure they tried one copy of each lens only. Still, I find their data useful and I still check their MTF curves from time to time.

Oct 31, 2009 at 03:01 AM
brainiac
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p.4 #2 · Dispelling the Zeiss superiority myth?


You may have discovered focus shift in the Zeiss at f5.6. But whatever the cause, the background text is clearly sharper than the canister and brush, leading one to ask how far behind the background text lies the real focal plane.

Oct 31, 2009 at 12:10 PM
carstenw
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p.4 #3 · Dispelling the Zeiss superiority myth?


Yes, exactly my point from earlier. The focus plane is in different places for the different lenses, at least the Contax and the Canon, so making proper conclusions is impossible. I would redo the test, and include an element which makes it easy to tell exactly where the focus plane is, like a ruler going back into the frame, and then redo the focus for each lens until they are all in exactly the same place. I do not think that the Contax was given an equal footing in the current test, so I am unconvinced of the sensationalist subject header.

Oct 31, 2009 at 12:56 PM
Empire
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p.4 #4 · Dispelling the Zeiss superiority myth?


dave chilvers wrote:
I purchased a Contax 50 1.7 because of ratings and have always been unhappy. My cheapo Canon 50 1.8 mk11 slates it would you believe!

I did a brick wall test Canon 50 1.8 mk2, Contax 50 1.7, Voigt 40 Ultron, Nikon 55 2.8 micro and Leica 50 f2 Sumi (latest) and the Leica beat them all centre and corners.



I bought two copies of the contax 1.7 and tested them (unfortunately not 100% scientifically) against an FL 55/1.2, a MK 1 EF 50/1.8, a Nikon 50/1.8 E, a Rokkor 58/1.2, a Revuenon 50/1.4, and a Tamron 28-75/2.8.

About a week after that I sold both contaxs.

I found both the FL and EF to be as good or better at same apertures.

I did like the colour which the contaxs produced (reds, specifically), but I found the difference so minor that it wasn't of any use to me.

The reason I sold them was that I could basically get all the performance of the planar 1.7 from my cracked-open, several-times-disassembled mk1 EF 1.8, with auto-aperture, matrix metering (or whatever canon calls it) and AF thrown in.

Interestingly, I found the bokeh of the Contax to be fine, whereas most people on the internetz claim it is terrible.

The FL 55 is a ******* sharp lens in the central 2/3 at f2 and onwards. I have yet to truly analise it's corner performance.

I wholeheartedly enjoy mine, even though its a little less characterish than the Rokkor. My main gripe with it is LoCA. Its get some strong cyan bokeh fringing going on at wide apertures. I'm also in two minds about its colour rendition and it isn't as good as some other lenses for micro-contrast.
oh and it flares like a match when shooting streetlamps at night.



Flare, f/8 or f/11:



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F4 (not the best sample in the world but what can you do):



This image is copyrighted by the owner




Crop - LR 2.4 sharpening set at 35, 0.8, 30 so almost baseline I just think it looks more natural with .8 radius:



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Oct 31, 2009 at 01:58 PM
you2
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p.4 #5 · Dispelling the Zeiss superiority myth?


But the EF 50 f1.8 has horrible bokeh; does it not bother you ?

Oct 31, 2009 at 03:04 PM
Alf Beharie
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p.4 #6 · Dispelling the Zeiss superiority myth?


The FL is certainly sharp...These are some in camera jpegs:

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This image is copyrighted by the owner











Oct 31, 2009 at 04:49 PM
 



Tariq Gibran
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p.4 #7 · Dispelling the Zeiss superiority myth?


^Those look great! The Bokeh even looks good. Do you see any LoCA in these in the out of focus backgrounds. I get the sense there might be a little cyan/green.

Oct 31, 2009 at 05:04 PM
Alf Beharie
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p.4 #8 · Dispelling the Zeiss superiority myth?


Tariq Gibran wrote:
^Those look great! The Bokeh even looks good. Do you see any LoCA in these in the out of focus backgrounds. I get the sense there might be a little cyan/green.


I dont see any...Even WO it has very little CA but I prefer to use it between f2.8-f5.6 as its razor sharp at f2.8 onwards and the DOF is more forgiving when focussing...Some of those were taken f2.8, some at f4 and some at f5.6.
I wonder if you can guess which apertures each were taken at?

Oct 31, 2009 at 08:06 PM
Maximilian
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p.4 #9 · Dispelling the Zeiss superiority myth?


brainiac wrote:
You may have discovered focus shift in the Zeiss at f5.6


Indeed, I remember that at focusing distance of 1 meter (reproduction ratio about 1:18) we measured the Planar 1,7/50mm having at f/5.6 a focus shift of 110 micron (namely closing from f/1.7 to f/5.6), which is about double as much as at infinite, and double as much as it would be ideal.


Oct 31, 2009 at 08:51 PM
Alf Beharie
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p.4 #10 · Dispelling the Zeiss superiority myth?


The car manual at the back of the target was exactly 73" (over 1.84m) from the lens. The toothbrush was between 2-3" in front.

Oct 31, 2009 at 09:52 PM
hans98ko
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p.4 #11 · Dispelling the Zeiss superiority myth?


Dispelling the Zeiss superiority myth?

Conclusion:
More like comparing 2 individual lenses

Reasons:
Wrong test procedure
(lens to target alignment and focusing in this case)
Wrong test condition
(changing light and flash)
Wrong test equipment
(digital camera and flash instead of proprietary equipment use by manufacturers)
Wrong test targets
(testing center to corner sharpness with object of uneven plane)
Insufficient test samples
(require a distribution curve to show average performance)

These are just a few items I noticed on this thread base on my experience working with (not for) and auditing optical and sensor manufacturers.


Nov 01, 2009 at 04:14 AM




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