Lens test - Yashica 50/1.7, Konica 50/1.7, Minolta 50/2 and Yashica 50/2

[assaft]

Hello!

I performed a test of four lenses (single copy of each one):
Minolta MD 50mm F2
Yashica ML 50mm F2
Konica Hexanon AR 50mm F1.7 (latest version)
Yashica ML 50mm F1.7 (latest version)

The idea was to compare the center sharpness/contrast/glow in an attempt to find the largest usable aperture for each lens in a low light condition. Note that I was not interested in the bokeh and corners performance.

The test was done on an e-pl2 (manual wb, raw-> exif-tiff using olympus viewer, no pp)

100% crops and full details are here: http://www.4shared.com/file/4nmm_SOe/lens_test.html
I can send the original RAW files if someone is interested.

Sp here are the fresh results:

• I found the Yashica 50/1.7 to be very good when stopped down to f2.2. In principle it is sharp at all apertures but the glow disappears only at f2.2. It is also relatively easy to focus with this lens thanks to its sharpness although the glow at f1.7 is distracting.
• The Konica 50/1.7 is doing quite well with respect to sharpness but it suffers from very noticeable glow wide open. It has to be stopped down to f2.8 to be usable, but in order to match the performance that the Yashica 50/1.7 shows at f2.2 it has to be stopped down even to f3.2. From f3.2 it is very sharp. The glow makes it quite hard to focus at f1.7.
• the Minolta suffers from lots of glow and softness wide open and has to be stopped down to f2.8 at least (or better to f3.5). At f4 it reaches the performance that the Yashica 50/1.7 shows at f2.2 and the Konica 50/1.7 shows at f3.2. At f2 It's hard to focus with this lens due to its softness and the glow.
• The Yashica 50/2 shows almost no glow and high contrast even wide open but at all apertures it is somewhat less sharp than the others. I think it matches the high performance of the other only when stopped down to f5.6. It's relatively easy to focus with this lens but I found the focusing on the Yashica 50/1.7 to be slightly easier due to its higher sharpness. [I know that some guys in this forum found this lens to be amazingly sharp so I don't know if what we see here is copy variation or something else; anyway, it is not that the lens is not sharp at f2.0-f.4, but rather that I found it less sharp than the others.]

In sum, the largest aperture of each lens that I found to provide very good results in terms of center sharpness/contrast/glow is:
Yashica 50/1.7 @ f2.2
Konica 50/1.7 @ f3.2
Minolta 50/2 @ f4.0
Yashica 50/2 @ f5.6

The samples of this specific configuration and a third/half/full stop up (to compare the difference) are in the gallery below. Note that the focus was on the left leaf of the tallest cyclamen; the wing of the bird is at the same distance from the camera, which is about 242cm.

The different apertures in which these photos were taken are evident in the shutter speeds.

All the rest can be downloaded from the file on 4shared
( http://www.4shared.com/file/4nmm_SOe/lens_test.html ).

Hope this will be useful!

 

[s_grins]

Thank you for fell thought and well performed test. I've downloaded all these files and 'ii look at them tonight. Looks that they tell the story.
B.R.
S
--
MFT in progress

 

[Anders W]

Mistaken post. Apologies!

 

[Ulfric M Douglas]

Your photo filenames are completely confusing.
Why didn't you name the files by the Lens and aperture?

 

[s_grins]

Hello!

I performed a test of four lenses (single copy of each one):
Minolta MD 50mm F2
Yashica ML 50mm F2
Konica Hexanon AR 50mm F1.7 (latest version)
Yashica ML 50mm F1.7 (latest version)

My assessment: at F=2.8
MD 50/2 = AR 50/1.7 = ML 50/1.7
ML 50/2 looks a little mushy

--
MFT in progress

 

[Alexsfo]

Would be interesting to see the comparison to Panny 20mm wide open at f1.7
--
E-PL2; 20mm f1.7, 14mm f2.5, 14-150mm f4-5.6

 

[assaft]

yeah, I should have done it... but it's too late now. next time

 

[assaft]

sorry about the confusion.

the naming convention I used is this:
[shutter speed id] [camera id] [aperture] [original file name].tif

So for example:
sp5_hx1.7_f3.2_P9034498

means:

shutter speed id: 5 ('5' stands for 1/3s; you can ignore this if you're interested only in the aperture, but anyway the full details for this translation are in the 4shared file)
camera id: hx1.7 = Hexanon 50/1.7
aperture: f3.2
original filename: P9034498

 

[Anders W]

Thanks for the test. I have a hard time sharing some of your conclusions though. For example, when it comes to "glow" (halation), the Hexanon at 2.8 is clearly superior to the Yashica 1.7 at 2.2. The only place where you can readily see the halation (if indeed it is present) in these test shots is along the upper white edge of the foremost flower. Here, the Yashica at 2.2 (and even more at 2.0) shows a pretty clear purple (almost blue) halation that the Hexanon lacks. I'd also say the Hexanon does marginally better in terms of micro-contrast. Look, for example at the vividness of the colors and the texture of the bird in the lower right corner.

Obviously, it would have helped here if you had shown (without the necessity to download) all the lenses at the same apertures rather than at different ones based on your prior interpretation. It would also have helped if you had shot a flat target, so that the target would have been in focus everywhere rather than in some places only.

 

[Anders W]

Would be interesting to see the comparison to Panny 20mm wide open at f1.7

I don't have any of the particular lenses at issue here, but if you want to see how the 20/1.7 compares with my legacy Minolta MD 50/1.4, you find it here:

http://forums.dpreview.com/forums/read.asp?forum=1041&message=39166126

 

[assaft]

Hi s_grins, Anders and Alexsfo!

Thanks for the inputs. I will perform a second test with a flat target and post the outputs in a more accessible/comparable way. And I'll also include the 20mm. But it will take me some 3 weeks b/c I'm just about to go on vacation (with the Hexanon and Yashica ).

I just wonder about one thing which I found striking during this test. It seems as if the camera selects different shutter speeds for comparable apertures on different lenses. For instance, it chose 1/10 at f1.7 on the Hexanon but a slower speed - 1/8 - at f1.7 on the Yashica. This is not always the case - sometimes, under different light conditions, it chooses the same shutter speed.

Similarly, when I stop down from f1.7 to f2.8 on the Hexanon, I expect to get a shutter speed which is 1.5 stops slower; but in most cases the shutter speed is only 1 stop slower. This phenomenon is almost consistent under all light conditions.

I have no idea about the source of this issue (maybe differences between t-stops and f-stops, maybe faults of the metering system, maybe the light power is not as stable as my eyes perceive it...).

This is not a scientific test of course, and I can't control all parameters, but if you have any idea how to explain this I would be very glad to hear it.

Thanks once again for the inputs.
Assaf