12" f9 RD Artar Sweet Spot?

[GhoSStrider]

So I know that Artars have a killer reputation as sharp lenses. I was curious, do they work best wide open, stopped down a bit, or stopped down a lot? I have a project coming up where I want to get as sharp of an image as possible. I'm specifically interested in the lens mentioned in the title, but would be curious to know about any of them.

Thanks in advance.

[Shen45]

I have a 19" RD in a shutter and wide open, stopped down or stopped down a lot it is far better than I will ever be. It is sweet no matter where I use it.

12" should just cover 5x7 but will be nice on 5x4 with movements. Some do report using these lenses up to 10x8 but I'm not sure on that myself.

[David A. Goldfarb]

I think these are optimized for 1:1 magnification at f:22, but they're also fine at other apertures and at infinity. Coverage is not great, so artars are usually best as longer than normal focal lengths for whatever format you're shooting (so 12" should be good on 5x7" and smaller).

[Capocheny]

Like Steve, I also have a 19" RDA and think it's a beautiful chunk of glass...

Personally, I stop it down to at least f16 or 22. So, I don't know how it performs at wide open.

Cheers

[CP Goerz]

A 12" Artar will cover 8x10 with movement in its sleep, not just barely cover 5x7. Its best at F32 for landscapes.

CP Goerz.

[Shen45]

That is good to know -- only thing is -- now I have to look for a 12" as well

[Joseph O'Neil]

Coverage is not great, so artars are usually best as longer than normal focal lengths for whatever format you're shooting (so 12" should be good on 5x7" and smaller).

Quite correct. While I love my 8.25" (about 209mm) RD Artar, it seems to barely cover 4x5. While it is a very sharp lens, I find I have always used it stopped down because I do get a wee bit of extra coverage at F22 as opposed to wide open, but not much.