Achromat close up lenses with Hasselblad

[Elmarc]

Hello all, I am looking into achromat close up lenses as opposed to Proxars.
Apparently the achromats exhibit less image degradation. Does anyone have first hand experience with these lenses?
Thank you

 

[xkaes]

Here's a list of 99% of them -- with some details -- to choose from:

http://fuzzcraft.com/achromats.html

 

[Elmarc]

Thank you Xkaes,
I did see that page while researching.
I am wondering if there will be any coverage issues if some of these lenses were designed specifically for 35mm and how the diopter/magnification strength may translate to a 6x6 format.

 

[xkaes]

The lenses (that's what they are) can be used on any lens and format, and vignetting is not likely to be a problem. However, they are designed with specific focal lengths in mind. For example, Minolta's No. 0 is a weak #0.94 diopter and gives its best results with longer lenses, such as 135mm, but can be used on shorter lenses -- but it's best to stop down. It has to do with the quality of the image -- not whether it can be put to use. I use the Minolta No. 0 all the time on shorter lenses without any problem -- and I would not hesitate to use them on my 4x5 lenses either (don't I don't need to use them for 4x5 close-up purposes). The farther you stray from the intended focal length, the more likely you will notice a drop in quality.

 

[Elmarc]

The lenses (that's what they are) can be used on any lens and format, and vignetting is not likely to be a problem. However, they are designed with specific focal lengths in mind. For example, Minolta's No. 0 is a weak #0.94 diopter and gives its best results with longer lenses, such as 135mm, but can be used on shorter lenses -- but it's best to stop down. It has to do with the quality of the image -- not whether it can be put to use. I use the Minolta No. 0 all the time on shorter lenses without any problem -- and I would not hesitate to use them on my 4x5 lenses either (don't I don't need to use them for 4x5 close-up purposes). The farther you stray from the intended focal length, the more likely you will notice a drop in quality.

When you mention 135mm are you referring to 35mm format?
I am looking to use these lenses on an 80 6x6.

 

[xkaes]

They are designed for specific focal lengths, the format doesn't matter -- but, as with any supplementary lens, the quality improves as the lens -- to which it is attached -- is stopped down. The lens covers the format, the CU lens simply shortens the focal length -- although it does decrease the image circle somewhat. This is normally not a problem because with close-up work, the lens is farther away from the film -- which increases the IC.

http://www.subclub.org/fujinon/close-up.htm

 

[Elmarc]

Thank you for the link. Very informative. It looks like the Minolta 0 will be a good place to start.
I'm curious to know how much of a difference there is between achromats and proxars.

 

[xkaes]

Maybe there is info on-line about the structure of Proxars. If they are more than one element, and coated, they should be pretty good.

 

[Elmarc]

Proxars are just one element. Single coated or multi (T*) coated depending on age.

 

[xkaes]

That said, as long as they are low/weak # diopters, the results should be good -- especially if stopped down.