Contax Planar 1.4/85 and Canon EF 2/100 Blind test

[Orio]

Since pictures are worth a thousand words, here's two pictures to show the extremes that this lens (the Helios-40 or 40-2) can obtain.

Wide open, king of bokeh:


Stopped down to f/5.6 or f/8, emperor of sharpness:


_

[Orio]

I have made some comparison shots, Helios-40 vs. Planar 85
Please note that today is a horrible day for test shooting, because there is strong wind and fast clouds and the light changes continuously, like, you meter the light, bring the camera to the eye, and light value has already changed.
So do not expect 100% consistency.

Now I go to lunch, later I will upload a zip with full size tif conversions to my server.
Since I have a cheap server, please download only if interested.

[Orio]

OK here's the file:

www.orio.ws/temp/hpcomp.zip

A few words while you download:

The total filesize of the TIFs after RAW processing was near to 900 Mb. As this was insane, I had to make some reduction choices. So I converted the files to 8bit depth and I converted them into 98% JPGs, which means unfortunately some compression but the quality rate is still near 100% and the gain in filesize is huge (from 509Mb to the current 49Mb)

Here's how I made the tests:
I used my 5D as it shows the full frame, I metered colour temperature with my Gossen Sixticolor and I input the Kelvin value directly in the 5D, bypassing the automatic white balance. This will allow to appreciate the different colour renderings of the two lenses.
As for light metering, I used my Gossen Multipro hand meter, and photographed in manual mode using the time value given by the hand meter, to bypass the camera metering and have constant metering for both exposures.
All shots were taken hand-held and both lenses had a hood on.
Unfortunately, like I explained, today wasn't a good day for lens testing. The wind and moving clouds made it impossible to make constant metering. I tried my best to make the couple of takes as consistent as possible, but it wasn't always possible (also because the slight difference in full aperture from 1.5 of the Helios to the 1.4 of the Planar added some visible difference that was too small for the camera's preset time increments to compensate).

Here I describe the 7 tests:

Test 1
wide open (Helios f/1.5, Planar f/1.4)
I photographed a linden tree in backlight, the aim was to help noticing chromatic aberrations, but the wind, and the abrupt change of lighting condition (in one shot you have clouds behind, in the other you have blue sky) made the test not 100% reliable, especially because there was a strong wind during the Planar shot while with the Helios shot the wind was much quieter. Also, by computer examination it turned out that I focused the tree in two different points from the Helios shot to the Planar shot. So please keep all these things into consideration.
Anyway even with all these factors, I think one can say that the Planar shows some purple CA, while the Helios shows none.

Test 2
wide open (Helios f/1.5, Planar f/1.4)
Another take for evaluating CA, this time a building with some flowers. Again the Planar shows some CA while the Helios shows none. On the other hand, the Helios shows a much poorer edge performance for both softness and corner vignetting. The central sharpness of the two lenses appears to be comparable.

Test 3
aperture f/5.6
This was a test to evaluate sharpness stopped down to f/5.6
The Planar appears to be clear winner for both centre resolution and edge resolution. The difference in edge resolution especially, is remarkable.

Test 4
wide open (Helios f/1.5, Planar f/1.4)
This is a paper flowers vase, as a test to near field focusing, wide open.
We can see the same things already noticed in the long range focusing tests. The purple CA is more evident in the Planar shot, and nearly absent from the Helios shot. The centre performances are comparable, perhaps the Planar seems a tiny bit sharper but this may be due do a difference in the focusing. The edge performance is much better in the Planar, and the bokeh of the Planar is also better, more creamy in the flat planes and also less annoying in the highlights

Test 5
wide open (Helios f/1.5, Planar f/1.4)
Same subject, but framing the flowers only, to evaluate the transition from focused to blurred.
This is the first and probably only test that has really surprised me. I was expecting the Helios-40 as a clear winner in the transition test, but the winner is the Planar without any doubt, much more creamier, smoother, and also displaying better colour saturation (although the saturation may in part depend from the slight difference in the exposure due to the f/1.4 - f/1.5 shift and the changing weather)

Test 6
wide open (Helios f/1.5, Planar f/1.4)
Same subject, but with real close up this time, to test close up performance.
This test is sort of a draw, the Helios prevails in the CA aberration department, showing absolutely none, while the Planar shows purple CA around the bright whites. The Planar prevails in the sharpness department, proving to be a sharper performer in the closeup range.

Test 7
aperture f/5.6
Same framing as test 5, but this time stopped down to f/5.6, to test sharpness stopped down in the near field focusing.
It's difficult to evaluate this test because unfortunately I focused the Helios farther than the Planar. As a consequence, more of the Helios shot is in the focused area, while most of the Planar shot is outside the focus area. I should repeat the test, but really don't have time. I think we can say however that the two performances, compared each in the sharpest point of the image, are comparable.

As a conclusion, I would say that the Helios-40 wins for the CA (or better said, lack thereof), while the Planar wins for the edge performance, the sharpness in the long field range, and surprisingly, also for the bokeh.
The substantially on par sharpness performance in the 1-2 meter focusing range, compared with the clear victory of the Planar in the long field range, shows I think that the Helios-40 is clearly a lens optimized for portraiture.

I conclude by remarking that in my opinion, if I used the Helios-40-2 in the test, instead of the Helios-40, the Helios-40-2 would have made a better performance in the sharpness department.

I will keep the file on the server for the weekend, on Monday I'll take it down.

[Orio]

Katzer, was that helpful? I heard nothing...

[Attila]

I thought this is an important review so I made permanent home for pictures at mflenses.com

[Orio]

[Attila]

?? I think this is 40-2, isn't it?

[Orio]

No, what I tested is my 1963 Helios-40 !

Not bad, a zero CA lens in 1963, eh?
They still had to invent the word "Apochromatic" that makes lenses value multiply by 10

[Attila]

Oh, no I put on images Helios-40-2.. I have to replace again

[Orio]