Decision time

[MattJenko]

I am at a bit of a decision point in my imaging. Stick or twist.

I have spent a bit of time converting my Skywatcher 250px OTA into an imaging scope, which gives me a rather fast 1.2m focal length, which gets me decent light gathering and scale for some planetary nebulas and galaxies. However, there are a few things that niggle at me with this setup.

• It is big. Need the AzEQ6 with 15kg counterweight. I setup/teardown each session, so it is an effort.
• There is no mechanism to screw my MPCC to the Moonlite I have, so it is a compression ring fit. Can slip when flipping and tricky to perfectly align/keep from tilting.
• The OTA itself has a little flex, so I am never going to get perfect collimation/tilt/focus/stars all night long.

I want to motorise the focusing, as well as possibly adding a secondary dew heater. I am wondering if it is worth it and if I should look at other options for ~1m focal length imaging. I recently picked up an RC6 which has a native FL of 1.3m, and I was going to use this for some spectro work, but it could also double as my galaxy, long FL rig too. It seems much more compact and more worthy of upgrading, but I would be be giving up a lot of photon rate in doing this, although on my HEQ5 it could do longer subs without too much hassle, but this is the UK....

The image below is what was achieved last night with the 250px, AzEQ6, Atik 414ex and ZWO filters. LRGB. 20 x 5 min L and 30 x 2 min for each RGB. It is good I think, but I have achieved some remarkable results with my much shorter focal length setup, and think if I am to move to the next level of quality at this FL, I may need to switch tack...

I'd appreciate thoughts. I am considering a decent 4-5" APO next year at some point, so this could potentially fill this gap, but it is still way shorter in FL than what I am currently considering.

 

 

[ollypenrice]

While that's a nice enough Crab I do think it's a bit soft to be honest. On the other hand the signal is very strong for the integration time, no arguing with that. You can have a focal length of around a metre from a refractor and, for my money, if the focal length can be had from a refractor then go for a refractor! It's only money  They just deliver such pin sharp results without fuss.

Olly

[MattJenko]

1 minute ago, ollypenrice said:

 I do think it's a bit soft to be honest.

Yep, that is my concern that I am not going to get a step change by putting effort into the 250px as opposed to trying something new. I've learnt a lot in setting this up, just think I might try a different route from now. Would love a longer FL APO :). Maybe going down in pixel size with a decent <1m apo would get me where I want to be... choices choices....

[Davey-T]

Have you tried the Mewlon on the Crab Matt, did you get the focal reducer with it ?

Dave

[MattJenko]

My Mewlon has pretty terrible off axis behaviour, and the tak flattener is eyewateringly expensive. I may give it a go though to see  

[MattJenko]

Added a lot more Lum last night to see what could be had with more data. Still not as crisp as my refrctor images, but this is a completely different FoV and image scale. Food for thought for me. Thanks all.

 

[Davey-T]

Looks a bit "sharper" Matt, how was your sky last night ? wasn't very good here.

Dave

[MattJenko]

Sky was a bit milky to be honest. Clear all night, but hazy.