Mutar I II & III and MTF

[Guest]

Hi there,

I know the Mutar convertor can increase focal length, reducing the resolving power as well as the effective apperture.

However, could anyone help to tell how the MTF is impacted ?

Francis.

 

[Guest]

Go to

Please, Log in or Register to view URLs content!

and download the .pdf - file of Tele Apotessar 2.8/300. There you can see how Mutar II changes MTF of this excellent lens.
These MTF-diagrams show much more than can be explained in many words. So far my opinion.

Regards
Dieter

 

[Guest]

..or just look in this forum in the download section:

Please, Log in or Register to view URLs content!

 

[Guest]

Thanks to all for your input.

I checked that the impact on MTF is not what I expected. MTF is a widely used tool to measure the quality. Is there any other tool(s) to depict the lens ? The reason why I ask is that (a) Some of the famous Zeiss lenses do not have the best MTF. (b) Some of Hard contrast Japanese lenses have the terrific MTF, but not get good comment.

So I doubt if the MTF is the spirit of lens.

Francis.

 

[Guest]

Hi Francis,



I agree with you that MTF is not everything, but you have to be aware that MTF is not the same for every brand. Zeiss is the only brand who publishes MTF charts of lenses out of the production.

All other brands show you MTF which they calculated on the computer but nobody knows whether they achieved to hold up this "theoretical MTF" in the mass production. No information about this will be disclosed. MTF of other brand is therefore useless.

This is why the likelyhood to have a Zeiss lens which has the quality seen in the MTF sheet is very high if you buy one at your dealer. If you buy a Minolta et alii of course there can be good ones, but it is less likely that the one you are buying has the same level as what you see on Minolta mtf computer charts (if they publish them at all).

This is the reason why ALL brands have very good lens tests in photomagazines. The producer is sending the lenses after making sure that this lens is the best one out of the production. But no guarantee, that the lens which was produced half an hour later has the same quality as shon in the model-MTF charts.

dirk

 

[Guest]

Hi Dirk,

I understood what you were saying. These also reasons why I have Contax systems since 1989. If calculated my very first Yashica and 50mm f2.0, I have been engaged with Y/C system for 20 years.

I raised questions because I really wanted to know some more other tools for measuring lenses.

Secondly, I have a 70-210 f3.5 which is not popular even in 2nd hand market nowadays. Looking at the MTF. It is not so good as 80-200 f4.0. But I do appreciate the job done by the 70-210 f3.5. It works perfect to me to all sort of performance from color reporduction to resolving power.

If you have time, let me know your comment on 80-200 f4 vs 70-210 f3.5.

Thanks,
Francis.

 

[Guest]

>Hi Francis + Dirk If you look at the Zeiss website, and the section on camera lenses, you can find information on MTF. Also, they state some reasons for their high price, namely that Zeiss lenses are tested, not just random s&les taken. Product quality thus is better. Also, in a reprint from a Japanese interview, Zeiss remarked that in addition to the optical quality of the competition, which may be very good, there is the mechanical quality and workmanship which excels. The expression "overbuilt" comes to mind. Zeiss produces.

Tom

 

[Guest]

...I never used the 80-200 or 70-200 fot C/Y, so I can not judge really except with MTF..

But there might be alrready some comments in the forum in the c/Y lens section. If not, just open a new thread there...

dirk

 

[fulmaro]

Hy everybody,
is there anybody that tried Mutar III with Novoflex 400/3?
I use a Contax system with Aria, 28/2,8, 50/1,4, 135/2,8, and 28-85. I choose Novoflex to photograph wildlife and I am satisfyed with sharpness and contrast, but I would like something longer.