Quote:
Originally Posted by glend
Which camera would be a good match for that 6" TS scope? Native 900 reduced to 700. Seems out of ASI294 comfort zone. Bigger pixel?
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The specs for that scope without specifying the image circle say that it supports full-frame, so to use a sensor any smaller than full-frame is potentially throwing away good light. If you really want wide field and the best light collection then at the 900mm native focal length use a full-frame sensor and at the 0.79x reduced focal length of ~700mm, you could consider potentially using an APS-c sized sensor, depending on what size the reduced image circle shrinks to. Depending on the true image circle size (all we know is that it is supposedly greater than or equal to 43.3mm), it may, with the 0.79x reducer fitted, reduce to a minimum of 79% of that (34.2mm), which would clearly be more supportive of APS-c sized sensors, given the potential for vignetting/light fall-off* with the reducer fitted.
As a ballpark calculation using a full-frame sensor it should be possible to achieve the following image scales at the stated focal lengths:
Full-frame sensors at ~900mm = ~1.1 to 1.4 arcseconds/pixel (4.9 to 6 µm pixels)
Full-frame sensors at ~700mm* = ~1.5 to 1.8 arcseconds/pixel( 4.9 to 6 µm pixels)
With APSc sizes the image scale should be
smaller still (~33% lower) , given the reduction in the field of view. An APSc sensor would potentially therefore put the image scale
below/around 1 arcseconds/pixel, probably on the too low side for all but the very best seeing.
Long story short / minimum effort: You could try a full frame DSLR if you already have one
Best
JA