Zeiss -v- Yashica ML lenses - 200mm f/4

I've had the opportunity to do a side by side comparison of a couple of Zeiss and Yashica lenses. It's not the sort of thing I normally bother about but one of the lenses is the Yashica 200 f/4 ML C (compact) which has an excellent reputation and I was interested to see how it compared to its Zeiss equivalent. The other comparison is between the Yashica 50mm f/1.7 ML and its Zeiss equivalent. That will appear in another post (eventually). Sorry, won't be happening as I've sold the Yashica lens.

Zeiss                                     Yashica

The two lenses are very similar in size and weight. Here's the specifications for both:

	Elements/Groups	Angular field	Min. Focus	Aperture range	Size (mm)	Weight
Zeiss	6/5	12° 40’	1.5m	f/4 – f/32	66.5 x 122	550g
Yashica	5/4	12° 30’	2.5m	f/4 – f/22	64 x 113.5	535g

The Zeiss has a filter size of 55mm, the Yashica 58mm.

This is not a scientific comparison, just a few shots on each lens compared against each other. I attached the lenses to my Sony A7II and photographed the roof of a nearby house putting the corner of the roof alternately in the middle of the frame and in the corner of the frame. I took photographs at f/4, f/11 and f/22.

I also took photographs of some out of focus highlights and also of a blank wall to check for vignetting and another wall to check for distortion.

The last photographs of the wall (not shown here) showed both lenses have slight pincushion distortion with nothing to choose between them. What they also showed was the focal length of the  Yashica is about 95% of the Zeiss. This is contrary to what the specification suggests. I'm not able to measure the exact focal length but just did a comparison of the two.

Vignetting at f/4 was very similar with both lenses.

Yashica

Zeiss

The images of the out of focus highlights are similar.

Zeiss

Yashica

Here's the rest of the images to compare for sharpness and contrast. All the images are 100% crops.

Yashica centre f/4

Zeiss centre f/4

Yashica centre f/11

Zeiss centre f/11

Yashica centre f/22

Zeiss centre f/22

Yashica corner f/4

Zeiss corner f/4

Yashica corner f/11

Zeiss corner f/11

Yashica corner f/22

Zeiss corner f/22

Both lenses are showing chromatic aberration when used on my Sony A7II. More so towards the edge of the images as is usual. I don't think there's any significant difference between the two lenses though.

One area of difference between the lenses is their compatibility with converters. Zeiss made x1.4 (Mutar III) and x2 (Mutar II) converters specially matched to some of their lenses including the 200/4. These converters can't be used with the Yashica as they are mechanically incompatible. But other converters can be used including the Zeiss Mutar I x2 converter. I took some more photographs using the Mutar I and Mutar II converters. The images are 100% crops.

Yashica f/4 Mutar I

Zeiss f/4 Mutar II

Yashica f/8 Mutar I

Zeiss f/8 Mutar II

My conclusion is that there is negligible difference between the two lenses. Yes, you could say one is better than the other in some instances but it's not always the case that the Zeiss is better than the Yashica which is what might be expected. In normal use, I would be happy to use either based on these results.