RB 210mm KL APO or 250mm KL ?

[drew_persson]

I searched quite a bit and couldn't find anyone comparing these two lenses. I read that they're both great but

suspect the 210mm probably has an edge given it's healthy price premium.

 

Comments and experiences? Is the 210mm worth the extra money? Thanks!

[bob_hack]

I have only have the 250mm KL lens, but seeing no resonses yet, I will contribute what I can.

 

I am certainly very happy with it's performance. I see virtually no CA or purple fringing. It is my understanding that the SLD (special low dispersion) glass elements on the APO come into play more in the higher mm's. There are some makes where the non APO's beyond 200 are just not worth it, but that is definitely is not the case with the 250mm KL. I would suggest for 95 % + of your shots you will probably gain ... nothing, apart from muscles. SLD glass is denser, a slight increase in weight.

 

See also:

http://www.photo.net/large-format-photography-forum/00DiZ2

and http://wapedia.mobi/en/Apochromat

 

see ya, bob

[drew_persson]

Thanks for the info Bob, apparently there is a 250mm KL APO as well. (Earlier I was under the impression that the 250mm wasn't available with APO glass.)

[steve_rasmussen]

<p>Actually it is not the low dispersion glass that is dense but the high index, high specific gravity barium glass that is commonly used in conjunction with LD glass that makes it heavy.</p>

[drew_persson]

<p>I picked up a brand-new RB67 250mm KL (part of a four lens order from Japan) at a good price, & posted it for sale on the forum here. Still in the factory box and wrapping, haven't even broke the seal to take it out of the box. Will sell outright or work it into a trade for a used 350mm APO.</p>