Manual Focus Lenses Forum

pandreas68 · Joined: 24 Jan 2020 Posts: 96

Since a while I am concerned with the Carl Zeiss Jena Sonnar 4/300 for the Pentacon Six in the non-MC optical formula which usually is found as Zebra but also occurs in the same shape but black and knurrled lense barrel.

Sonnar 4.0/300 (non MC version!) on Pentacon Six

This lense is reported in some sources to be worse than the later CZJ Sonnar 4.0/300 MC which is shorter and has less weight. In some other sources the Zebra version is reported to be better than the MC version.

My actual main 300mm lense for my Sony Alpha II is a Prakticar 4/300 which is much lighter than the Zebra Sonnar and "MC Sonnar".

Sonnar (MC), Sonnar (non MC, same as Zebra) and Prakticar (from left to right)

I wondered how the Zebra Sonnar behaves on my Sony Alpha II. So I first went out with my Sonnar and took some fotos:

Branch in water hot by Sonnar 4/300 handheld (klick for full resolution)

Lake by Sonnar 4/300 handheld (klick for full resolution)

People by Sonnar 4/300 handheld (klick for full resolution)

With respect to resolution the Sonnar behaves as expected; with my usual resolution being only 10MPx I do not have a special demand (see here).

Next I thought how the Sonnar behaves if I want to have the lake scene completely sharp. And I wanted to see whether there is a difference between the Prakticar and Sonnar.

My first surprise was, that it is easier to obtain the respective setting with the Sonnar than with the Prakticar. The reason is that I need to focus the most distant point and the most closest point I want to get sharp and then take the middle and use the aperture to cover this area. On the Sonnar this is easier due to higher resolution of the distance engravings though it could be even better. Estimating distances is no option since my lense adapter is not precise enough.

When setting the aperture I did it according to my readings on the lense. For the Sonnar I used 11 and for the Prakticar 16. A reason for this may be that the Sonnar is a middle format lense and thus the defth of field (DoF) for the same aperture setting is deeper due to a bigger circle of confusion (CoC).

Lake shot by Sonnar 4/300 at f/11 handheld (klick for full resolution)

Lake shot by Prakticar 4/300 at f/16 handheld (klick for full resolution)

Any clear winner? At least I would say that the Sonnar isn't worse than the Practicar.

I also did an aperture series with the camera standing on my gloves on the ground, releasing by 10sec timer. The problem of this series however is, that I did use the same distance setting with middle of far and close point and thus not the same for both lenses. I better repeat this series before I post the whole series. Nevertheless I'd like to show the result for f/4.0:

Lake shot by Sonnar 4/300 at f/4.0

Lake shot by Prakticar 4/300 at f/4.0

There is quite a difference in the behavior of both lenses beyond the fact that both lenses are not focussed onto the same point. As last picture here the lake scene seen through a Flektogon 2.4 / 35mm

Lake shot by Prakticar 2.4/35

All together so far I'd say that the Sonnar 4/300 is a heavy lense which nevertheless is useable for landscape fotography even on digital full format system cameras. The results for my taste are better than the result of the Prakticar 4/300. A disadvantage of course is that it is twice as heavy as the Prakticar 4/300 and thus I will not use it for longer hikes or even in the mountains.

Andreas

KEO · Joined: 27 Sep 2018 Posts: 811 Location: USA

Very informative post.
Thank you!

pandreas68 · Joined: 24 Jan 2020 Posts: 96

pandreas68 · Joined: 24 Jan 2020 Posts: 96

Now I made it to shot aperture series for both the Sonnar and the Prakticar again.
I choose two different settings of focus. The first series focusses on the middle penninsola in depth, on the very right grass directly at the water. The second setting focuses on the trees in the right backgound.

Somehow it was very difficult to achieve compareable conditions. And I first made the mistake to forget an R1.5 filter on the Prakticar. So I had to shot those pictures twice. Somehow for some shots the R1.5 pictures are better than those without filter. Maybe the reason is better focus in the first series with filter. Therefor I also provide the series with filter mounted.

The focus is always a problem, since again I worked without tripod (no space in backpacker). When adjusting the camera on the scene after focussing it may have happened that the focus ring was slightly moved. I also can't rule out that I used different trees for the focus in the back.

For apertures 22 and 32 pictures get blurred; It may be due to long exposure times. I should have changed the film speed setting to rule this out, even if film speed may have influence on the pictures.

Another thought was the source of the pictures. Finally I decided to use the 24MPx jpgs directly coming out of the camera rather than to use RAW files and doing somehow RAW Therapee conversions which may influence results in one or the other direction.

Before showing and comparing some details I provide all complete pictures. For sake of readability I only list the links of the whole pictures; by clicking the links they can be opened from flickr e.g. using gimp.

All pictures are taken with exposure adjustment of -1.

This series is focus in the middle for the Sonnar:

Sonnar, focus to middle f/4.0
Sonnar, focus to middle f/5.6
Sonnar, focus to middle f/8
Sonnar, focus to middle f/11
Sonnar, focus to middle f/16
Sonnar, focus to middle f/22
Sonnar, focus to middle f/32

This series is focus in the middle for the Prakticar with filter R1.5:

Prakticar with filter R1.5, focus to middle f/4.0
Prakticar with filter R1.5, focus to middle f/5.6
Prakticar with filter R1.5, focus to middle f/8
Prakticar with filter R1.5, focus to middle f/11
Prakticar with filter R1.5, focus to middle f/16
Prakticar with filter R1.5, focus to middle f/22
Prakticar with filter R1.5, focus to middle f/32

This series is focus in the middle for the Prakticar without R1.5 mounted:

Prakticar, focus to middle f/4.0
Prakticar, focus to middle f/5.6
Prakticar, focus to middle f/8
Prakticar, focus to middle f/11
Prakticar, focus to middle f/16
Prakticar, focus to middle f/22
Prakticar, focus to middle f/32

This series is focus in the back for the Sonnar:

Sonnar, focus to back f/4.0
Sonnar, focus to back f/5.6
Sonnar, focus to back f/8
Sonnar, focus to back f/11
Sonnar, focus to back f/16
Sonnar, focus to back f/22
Sonnar, focus to back f/32

This series is focus in the back for the Prakticar with filter R1.5:

Prakticar with filter R1.5, focus to back f/4.0
Prakticar with filter R1.5, focus to back f/5.6
Prakticar with filter R1.5, focus to back f/8
Prakticar with filter R1.5, focus to back f/11
Prakticar with filter R1.5, focus to back f/16
Prakticar with filter R1.5, focus to back f/22
Prakticar with filter R1.5, focus to back f/32

This series is focus in the back for the Prakticar without R1.5 mounted:

Prakticar, focus to back f/4.0
Prakticar, focus to back f/5.6
Prakticar, focus to back f/8
Prakticar, focus to back f/11
Prakticar, focus to back f/16
Prakticar, focus to back f/22
Prakticar, focus to back f/32

Added 2/9/20:

This photo shows the frames which I used in the following comparisons:

Frames used for comparision (shot by Sonnar f/16; created from Raw; click for full resolution)

pandreas68 · Joined: 24 Jan 2020 Posts: 96

This first comparison is for the middle peninsula and the sharpness of the lenses. It seems that the focus is best met by the Prakticar with filter mounted.

Sonnar

Prakticar with filter R1.5

Prakticar without filter R1.5

The Sonnar shows some unsharpness in the range of some up to 4px. The souce is unclear for me. Might it be spherical aberration?

The Prakticar with R1.5 mounted shows unsharpness in the same magnitude but with color fringes. I have the feeling that the Prakticar is very prone to longitudinal chromatic aberration and that it comes because the focus should be closer at the water. But in that case it should be green rather than purple, shouldn't it?

The Prakticar without filter shows for my eyes slightly more unsharpness, maybe due to focus.

pandreas68 · Joined: 24 Jan 2020 Posts: 96

This comparision is on the top right of the picture when focus is on the middle:

Sonnar at f/4[/img]

Sonnar at f/8

Sonnar at f/16

Prakticar at f/4

Prakticar at f/8

Prakticar (with R1.5) at f/16

The Sonnar shows green chromatic aberration which gets less towards f/16.

The Prakticars green chromatic aberrtion at f/4.0 is quite comparable to Sonnar's but bith closing aperture the Prakticar's aberration does not disappear but gets sharper. Does this mean that it is longitudinal chromatic aberration for the Sonnar and lateral chromatic aberration for the Prakticar?

Some more comparisions to follow soon...

pandreas68 · Joined: 24 Jan 2020 Posts: 96

This comparision shows the middle peninsula when the focus is in the back. Due to depth of field at f/16 it should be totally sharp.

Sonnar f/16

Prakticar f/16

Prakticar with R1.5 f/16

All three pictures show the same pattern of rainbow colors in the horizontal leaves. I could not clearly assign these pictures to one of the lenses since they are so close together for my eyes.

pandreas68 · Joined: 24 Jan 2020 Posts: 96

This comparison shows a detail of the little island in the front close to the left lower corner which should be slightly out of focus at f/16, since the focus is in the back:

Sonnar f/16

Prakticar f/16

Prakticar with R1.5 f/16

In all three lenses there is a fringing visible. It seems to be more visible in the Prakticar than in the Sonnar.

Are those comparisons enough to come to a conclusion? Or are any important details in the picture overlooked and thus missing?

pandreas68 · Joined: 24 Jan 2020 Posts: 96

This comparision shows a small part from the middle peninsula of the pictures with focus being there. It compares the pictures from the Sonnar at aperture 4 and 8. The jpgs are those as they come out of the camera and some which are created from Sony compressed RAWs by using Raw Therapee. When using Raw Therapee the profile Auto matched curve ISO low" is used with following additions: sharpening and local contrast is switched on but not changed. At one also the edge sharpener is switched on.

Sonnar f/4 from jpg

Sonnar f/4 from RAW

Sonnar f/8 from jpg

Sonnar f/8 from RAW

Sonnar f/8 from RAW with edge sharpening

When using the RAWs some kind of green fringing is visible which is not visible in the camera's jpg; on the other hand the rainbow pattern (visible especially at aperture 8 in horizontal leaves) is not existent in the RAWs. What happens here and especially in the camera?

The rainbow pattern is some 3-4px broad. The circle of confusion is some 4.8px in diameter. So the camera's effect in jpg generation keeps within this limit. Also the lens keeps within this limit starting from aperture 4. Maybe it makes sense not caring too much about pixels.

My main goal of the test shots was to look for the quality of the Sonnar by comparing to the Prakticar. Compared to the Prakticar its quality seems to be at least equal if not better due to lower CAs. On the other hand the Sonnar is more than twice as heavy as the Prakticar.

Doing the test shots I've learn't that it is quite difficult to do comparisions in non standardized environments and that the pictures show quite different behavior in their different corners for the different focus settings. Even the camera's jpg generation seems to have an effect which is not neglectible.

Why did I buy the Sonnar? Main reason: I have a Pentacon Six and mainly therefor I bought it. Somehow I am also attracted by the development history of the 300mm lense at Zeiss Jena. The Sonnar 300mm from 1963 was the last which was mainly calculated for improving the quality of the lens. Both, the so-called MC-Sonnar and the Prakticar were mainly calculated to achieve cheaper lenses respectively lenses which bring more money than they cost; they did not seek to improve quality but stayed within a good optical quality. Maybe knowing now its quality on full format I will take it also from time to time there, but I guess most times I'll use the Prakticar due to size and weight. Both lenses are quite cheap, cheaper than the MC-Sonnar wich I just have but which I wouldn't buy anymore.

pandreas68 · Joined: 24 Jan 2020 Posts: 96

At the end of the post in which I listed all original camera jpgs I added an overview which shows the frames for the comparisions. Please feel free to contact me if you wanted to have the camera's (compressed) RAW files.