Sharpness Sears vs Yashinon

[truls]

I did a small and non Scientific sharpness test. Sears 50mm/2.0 m42 vs Yashinon DX 50mm/1.4. The Yashinon lens are far more known than the Sears opponent.

Sears 50 mm @f 2.0 - 100% Crop:


Yashinon 50mm @f 2.0 - 100% Crop:


Sears 50 mm @f 8.0 - 100% Crop:


Yashinon 50mm @f 8.0 - 100% Crop:


I would say the Sears holds up well, considering the price difference.

Those small "hairs" on the flower are almost invisible to the naked eye...

[Stephen]

Frankly I am very surprised the Yashinon is not behaving better, than not expecting the Sears to be a good lens. On the face of the shots the Sears F2 lens is about 100% better!

Also the Yashinon is showing signs of aberrations at the edge of object, especially at F 2.00.

I assume the test were one on the Olypmpus digital, so easy to replicate again with a "Flatter target", and carefully taking a series of shots at "close" to "over focus", to find the sharpest possible result at each aperture.

In theory the Yashinon should beat the Sears, the Yashica made lenses were good sound design and build, so the surprising result with the Sears being so much better may just mean...

* A faulty Yashinon.
* A excellent Sears,
Or simply the manual focus on the Olympus takes some getting use to!!! ( maybe the most likely, I have the same camera ). I assume the magnified area in the middle of the screen was used to focus the lenses, and that the Adaptors were the same? or is the Yashinon a bayonet version.

Different adaptors on the digital should not make a difference to focusing, adjusting the lens to the focus point should make both as sharp.

I have had some odd results with lens that are being compared on digital, but are a small difference in focal length, or the aperture results in different rear element diameter.

Bigger differences occur that expected, and it is down to the design of the MOS sensors and the software in the firmware in the camera. Digital designers expect modern lens to be used and have corrections built in that suit modern zoom lenses.
When an older lens is used sometimes it throws the corrections, and two seemingly similar lenses may behave differently.

You can partly correct for this by using the RAW files, these do not try to correct so much, but even then the software that assembles the RAW file has corrections in it that are difficult to get around.

On the other hand if an older lens displays say barrel distortion, we have the advantage this can be entirely corrected by Photoshop etc.

The point is that some comparison tests may be thrown a bit by the software in the camera, and it all depends on the lens being tested.

Hope this helps, it may be a repeat of the test in small steps will reveal which is better, but the Sears looks good, very good!

[truls]

Stephen:
As I said, the test is not scientific and I could also have done some wrong, I am no digital expert at all. Yes, the pics where taken with Olympus MFT, the same camera you have. I will test once more, this time with some other subject, may be a sharpness test chart if it exists. Both lenses are m42 mount, and in good condition, except from the usually small dust particles every old lens have. I don't think the Sears lens is special, my other Sears 50mm 2.0 in PK mount share the same type of sharpness in pictures.

My suspicions would be that maybe some Sears lenses are made by some major lens maker? Pentax?

In the original test I should test against my Super Takumar 50/2.0, but I could not find the lens at the moment... The Yashinon lens is not faulty, I have many sharp images taken with this lens. In practical photography no one would have seen the difference in pictures between the Sears and Yashinon lens. Testing of lenses is womewhat of a double edged sword, as lenses also have other capabilities as well. Sharpness just one.

Could the amount of glass make a difference? The Yashinon contains a lot more glass than the Sears lens. And could more glass using a modern digital camera make the image softer? This I do not know.

What I do know, I will certainly buy some more Sears glass. Most people skip Sears lenses, and the prices reflect this.

[Stephen]

The Sears were made by Tokina, as far as I can check. digital cameras do not always work well with all older lenses, but it is usually an issue with contrast, not sharpness.
Contrast can vary between two lenses due to the reflective surround of the mount. film did not reflect much, but glass does, and the MOS sensor has glass surface.
Lens like Stenheil have a chrome back, and this reflects, reducing contrast and adding flare.
The best performance comes by covering the back of the lens with a temporary card ring (black), with a hole the diameter of the back element, cures a lot of flare and soft glow.
A good test target is a newspaper, lots of fine detail and available!
Stephen

[casualcollector]

Sears lenses came from different makers at different times. There are instances of Yashica buying lenses from suppliers other than their usual supplier cum subsidiary Tomioka. Troll the postings here for a look into the mysteries of who made what! forum.mflenses.com/manual-focus-lenses-f3.html

I have Sears lenses from Sigma, Tokina and a Korean builder. The 50-55mm normals depended on who the cameras were being bought from and include Mamiya, Ricoh, and Chinon, at different times. To muddy the waters further, the 55mm f-1.8 and 55mm f-1.4 from the three mentioned are so similar, once you get past the cosmetics, They may have all come from the same source or were built to the same design. I made a post about that somewhere years ago. A comparison of five 55mm f-1.8 lenses. I'll link it if I find it.

[casualcollector]

Found. cameracollector.proboards.com/thread/4682/different-normal-lenses-all-same

[Deleted]

Merchandiser brand lenses were often made by the low bidder. Even Vivitar sold lenses made by Tokina, Kiron, etc. The major camera manufacturers, Nikon, Pentax, Minolta, Mamiya, etc., almost never sold lenses under another name unless they made the camera, too.

[truls]

casualcollector: Thanks for the old and very interesting post.

I guess you are right, lenses resemble each other and might be made by few manufacturers. After all, lens science is older than the lenses itself, and a lens has to be constructed a certain way to be sharp and correct optical errors.