180 ED Nikkor vs modern 70-200 vs 135 Sigma ART?

Tomx72 wrote:

Thank you, that was a deal-saving input:) Meantime I keep finding cloudynights references where people regularly used the nikkor stopped down to f/4 - no thanks, I need something decent at 2.8, my guiding skills/equipment are not ready for 5min+ subs...

Another interesting old piece of glass: the 1990 model Sigma 2.8/180, read somewhere that it is better than the nikkor.

BlackgumNate wrote:

There's no comparison between the Nikon 180 and the Sigma 135, the Sigma is far superior, I've always found the nikkor to be over touted. I used to own the 180mm but it's fringing is annoying and from what I remember wasn't much usable until f/3.2 or 4. The sigma is near perfect at f/2.

I'd have to check some older images to see how the 180 rendered stars (in corners etc.) but there's nothing I miss about that lens for astro.

nate

I would concur with Nate as I have the Nikkor 180mm and it is indeed unusable until you stop down to about f4, which sort of defeats the purpose of getting an f/2.8 lens in my opinion.  The blue fringing around stars is pretty bad at f/2.8, and I wasn't able to effectively deal with it either in a raw converter or in post-processing in Photoshop.  I don't use it much, which is disappointing.  If you do stop down to f/4, it's tack sharp...so I may use it sometime for a target that happens to really suit the field of view.