Hello!
As the milky way season is nearing I am planing to try some wide-field astro imaging. I have tried previously but it is not that simple with the FA 50 1.4. Something wider would be a lot better (especially on a APS-C sensor). So as I have my k500 and also the NEX 5N I think it is wise to go for a K mount lens(es) and use an adapter for the NEX. So I have been reading quite a bit and have come to a conclusion that Samyang (Rokinon) lenses are one way to go. Little coma, cheap, sharp, bright. I also have seen an opinion that they are very flimsy - inadequate QC, construction made of plastic and glue and that there is a chance that they will "fall apart" if I shake them a bit more roughly. Then there are old version SIGMA lenses - I am looking towards 28 mm F 1.8 EX - screw drive, but applicable to FF
The new version of 30 mm 1.4 art also looks appealing, but then again it is APS-C lens but has HSM. The 35 mm art version is FF but it is considerably pricier and I don't consider it to be "wide" - especially on a APS-C. Ok sigma has the brand NEW 24 mm ART version which is really really what I would like to get if it had a compatibility with pentax but it doesn't. Ok, there are some statements that due to upcoming FF pentax, sigma is planing to re-release some of their lenses also for K-mount. When? So All I wanted to say is that I am lost .
So I have the options:
1) Samyang 14 mm F 2.8 (compatible with FF)
2) Samyang 16 mm F 2.0 (compatible only with APS-C)
3) Samyang 12mm F 2.0 (only for NEX mount and for APS-C)
4) Sigma 28 mm F 1.8 EX (compatible with FF)
5) Sigma 30 mm 1.4 ART (APS-C)
6) Sigma 35 mm ART (FF, but I don't think it is a good idea considering the focal length).
7) Sigma 24 mm ART (Hypothetically if and WHEN it becomes available for pentax)
So can you please share your experience, opinion, knowledge. Obviously AF capability would be much appreciated as it would make these lenses more versatile. So yes - I am a bit lost here.
Please shed some light as I am sure there are other underwater rocks that I don't know about whereas some of you might.
Also a very serious question about SIGMA - is there a reliable info on which lenses they plan to re-release for pentax? So some info in this direction would be also very welcome.
Thank you!