Anyone out there had a chance to use the Samyang 35 mm f/1.4 at wide apertures for star photography yet? I am particularly keen to find out how well this lens deals with coma issues in the corners at f1.4 and f2 using full frame cameras.
Any sample images would be appreciated too. Thank you.
wow... spot size is awesome on the zeiss... coma well controlled on the samyang but the spot size isn't as good. still, for wide angle, artsy shots it should work (especially at F2)
Re: Astronomy, I hope the takeaway is that any of these fast 35mm lenses is not very appropriate for astronomy. It may seem counter-intuitive, but the best lens for stars is a slower lens with excellent corner image quality and a flat field, such as almost any of the Zeiss ZM wides, especially the 25 Biogon, the latest Leica R28 Elmarit, or slower versions of the ZE/F wides.
Point light sources will not be point light sources in the corners of faster, more difficult to correct lenses. Sensors don't have reciprocy failure like film, so there is less of a need for faster exposures. Current methods of astrophotography involve stacking multiple exposure frames in software.
Dear Jim,
Please do understand that closing every stop means doubling the exposure time, and in astronomy the exposure time is in the minutes or even hours. In many area, there are too many rainy and cloudy nights, so when one fine, clear night finally comes it is just too wastful to close down too much (or use a lens too slow).
We usually combine multiple sub-exposure of minutes to get the equivalence of a deep exposure to get around dark current and reduce the possibility of screwing up (a night plane flying over). But it is still the same principle: you must get as much photons as possible to minimize noise, otherwise the image is not "presentable".
So the astrophotographer has to compromise in term of speed and image quality. Usually the corners are less important so if the image is good at the edge of APS format it is usually good enough. The truly poor corners can be cropped off later.
