Anyone gone from a 414ex mono to asi2600mm camera or similar

[iwols]

Hi just wondered if anyone had gone this route or similar and had any comments/thoughts/advice thanks

[Starflyer]

I went from a 314EX to a 460EX to a QHY 268M (same sensor as the 2600mm) .  The 268M is sensitive but, like all CMOS cameras, is finiky over calibration frames and my flats suffered from a bright central circle (most likely from reflections with my Baader filters), I couldn't solve this and ended up changing to Chroma filters.

The 460EX was a joy to use, very low noise and IMHO as sensitive as the 268M, I still have it although it hasn't been used for a couple of years.  I wanted a bigger sensor than the 460EX so the 268M was the logical way to go, apart from the added expense of the filters I'm happy with it.

The bigger sensor is more far more demanding of your optics, any tilt will show up in the edges of the frame and you'll need to experiment with optimising backspacing for any coma corrector or flattener / reducer, or again the stars at the edges will suffer, the approximation of 55mm just doesn't cut it.

[iwols]

Thanks So the 55mm back focus isn't a problem if you only have the filter wheel in your chain

[Starflyer]

1 hour ago, iwols said:

Thanks So the 55mm back focus isn't a problem if you only have the filter wheel in your chain

I meant that just setting it at 55mm probably won't give you the best results. Be prepared to have to experiment and tweak the distance to get the CC / flattener to give you decent stars to the edge.

[tomato]

I started with an Atik 314, then went 383 mono before moving to IMX571 sensors. I use flats and dark flats and still use darks although a lot of imagers have dispensed with darks for this sensor. How careful you need to be with the spacing depends to some extent on your OTA, an f2 RASA needs more careful setting up than an f7 Esprit, but that is just my experience. 
However, I should point out that I’m more relaxed than a lot of imagers wrt star shapes, I’m happy to let the processing software fix minor aberrations rather than use precious sky time trying to get things perfect.