ZWO ASi 174 or 178

[richard ashbee]

Which would you choose for Solar and why, would a UV/IF filter improve the image?

I plan to get the Solar Scout 60mm

[michael.h.f.wilkinson]

I have both. The ASI174MM works best in my H-alpha rig, which works at F/25 or so, so the large pixels of the ASI174MM are just about the right size. The ASI178MM has smaller pixels, and works better at F/12 or thereabouts. This is fine for my 80mm F/6 for full disk, and for detail at F/12 with a 2x TeleXtender. The Solar Scout is F/15.5, so you either need a bit of focal reduction with the ASI178MM (or live with the oversampling), or you need to add a 1.5x Barlow for the ASI174MM. The ASI290MM has slightly larger pixels than the ASI178MM, but is rather  smaller in surface area. The ASI1600MM is near perfect in terms of pixel size vs focal ratio, but is rather expensive. I am not sure how large the image circle of the Solar Scout is in mm.