Refractor for pier based DSO imaging

[iapa]

Currently have 8" variants of:

• f10 SCT
• f2 RASA 
• f5 Newtonian

\plus

• f6 (ish) Equinox ED80 Pro refractor
• f4 10" Newtonian.

I am looking to rationalise and try to replace as much as possible with a refractor.

Thais would be mounted on either a CGEM-DX or CGXL pier mounted ( I have both)

or on an AVX (also owned) if I am traveling (tempted to keep he ED80 Pro for travelling tho)

Let's assume the budget is no more than £5K.

As is is going o be primarily for DSO, a longer focal length may be more beneficial. 

It would be primarily to support the RASA to get the closer details on my primary targets.

Any of the above can be regarded as "disposable" while considering options.

 

 

 

 

[MarkAR]

The Altair Wave 152 is in budget, if it's anything like my 115 then it's a good 'un.

More importantly, it's in stock.

 

Edited September 13, 2020 by MarkAR

[iapa]

Looks nice.

any other suggestions?

50 wish seems good, anyone better than f8 that anyone knows of?

[ollypenrice]

There's little point in considering the optics without considering the camera and the mount since they make a single entity in use. So the first question is, 'What is your guide RMS in arcseconds?' (If you give PHD your guider's pixel size and focal length your RMS will be given in arcseconds.) Whatever is your guide RMS, mulitply it by two to get an idea of the resolution your mount will support. If your guide RMS is 0.5 arcsecs, don't try to image below 1 arcsec per pixel.

The resolution of an imaging rig is not determined by focal length or by pixel size but by both. There are lots of online calculators but I use this one: http://www.12dstring.me.uk/fovcalc.php

You then have to consider the chip size and whether or not 'scope x' can cover it. Not many scopes will cover a full frame (35mm) chip, for instance.

Olly