The camera automatically crops the resulting images to APS-C size.
I just ordered the EF version, on B&H for a mere $202. It arrives today, along with an Irix 15mm f/2.4. I shoot astro and will use them primarily for that. I don't mind having to use the Rf-EF adaptor If this new Samyang is APS-C, as I think, it won't interest me. I have the EF 11-24 f/4 which may be huge and heavy, but is a great lens. and the VND filter that I have for the adaptor that accepts filters is quite convenient. I have the Rok 14 f/2.8, which is just OK (prefer my RF 15-35 2.8 for astro)...and the Rok 24 1.4, which is quite good, But my Sigma ART 28 and 35 f/1.4 are superb~
I use an R7 with the Canon RF100-400 and a Sigma Sport 150-600. Both are FF lenses but I don't see why converting them to APS-C would provide any advantage. With lenses this long, the size and weight are dictated by the focal length of the lens and diameter of its front element. If I wanted a 100-400 FF FOV, I'd use a 60-250 lens with the R7.
Exactly. Despite repeated explanations coupled with the obvious complete lack of 'crop-specific' long telephoto lenses, some people keep asking for them. Once you're beyond ~300mm, there's no advantage to a smaller image circle because the image circle is no longer limiting to the design. Living the dream is fine, but asking for something that's completely unrealistic for technical reasons is pretty foolish. I prefer to live in reality.
What is your experience with the IRIX 15mm for astro/ nightscapes? I´m looking for a viable, affordable option to get for next year.
The Samyang 12mm is a well regarded astro lens and the F2 is a huge benefit there, together with the minimal coma.
Sigmas offering is f2.8 so the Samyang is one stop faster. Canons lens starts at f4.5 so the difference is over 2 stops (2 1/3 stops exactly?!). There is a huge difference if you want to shoot the night sky or cities at night time.
