Hi Sam.
My ASI174MM arrived here in New Zealand yesterday thank you very much, with very fast delivery as usual, and even arrived on a clear sunny day, even if it was a day with terrible seeing. That seeing, my only moderate level of expertise with solar ha imaging, and the fact the camera and Quark were mounted on a very cheap 102mm f/6.5 achromat should probably all be taken into account when thinking about the quality of the attached image.
First, and very promising news, is that I couldn't see any sign of newton rings, unlike my small sensor Aptina CMOS camera which does show them unless I use a reducer!
This image was unreduced, mainly because I only have a 1.25 inch reducer which naturally showed heavy vignetting with the 174's large sensor when I tried it. I will get a 2 inch reducer and Daystar's 2 inch EP holder for the Quark and see if that combo works with the 174. Does anyone here have other ideas for a commercially available reducer that might work with the ASI174's large sensor?
The camera seems to be working fine so far in this first session with latest betas of both firecapture and sharpcap. It was running using USB2 on a very underpowered and old 10 inch screen netbook, giving me only about 10-13 FPS at full resolution, but that seems ok for such an old and low powered netbook with usb2 using the camera's full resolution.
The image looks soft out near the left and left-bottom edges to me, and the prominence down there is very fuzzy indeed, and that might be due to aberrations wider in the optical train that weren't apparent with my smaller sensor, perhaps due to the low quality cheap refractor, and/or the Quark itself, and/or due to the very poor seeing. There are also some brightness gradients more apparent across the larger sensor than I've seen with the small 1/3 inch Aptina sensor, but I think isn't unexpected.
Overall though I'm happy with it for a first image. I'll try capturing with a much faster laptop with USB3 ports next.
Cheers,
Chris M,
New Zealand
