imaging with achros

[ZeroID (Brent)]

I played with a C80A light blue filter, standard photographic. They are just about giving them away free nowadays as DSLRs don't need them. $10 for 5 !!
It has a much lower in height and intensity but similar profile to an Astronomik CLS (Visual). What it did was blue the sky obviously but also chopped out a lot of the LP in the red region and it reduced chroma because it cut back that red component. It required a lot more exposure but was surprisingly effective. Processing let me recover a lot of the red selectively and it kept star bloat down as well. I have intentions of trying it with my IR modded camera when the clouds allow it.

[Willow127mm (Brad)]

Hi guys I have bought a 120mm F8.3 Achro and I,m concernd it will now be too slow.
Is there any good news here like maybe the CA wont be quite as bad with the longer focal length or is it all bad news.
I know planetary work likes the longer FL but I,m more interested in DSP
I couldn,t resist the price of this scope but I feel I may have jumped the gun.
Any help much appreciated.
Cheers Brad

[RobF (Rob)]

There's no perfect scope Brad. We all want DSO gratification early on, but remember to enjoy the ride as you learn.
Your mount and scope should be fine to learn the basics of polar alignment, pointing model, navigation/framing, guiding, image calibration, processing.

Once you know you love this stuff, nothing to stop you upgrading later. By then you'll probably have joined a few local imaging session with like-minded locals and have a much better idea how to invest your had-earned dollars.

On reasonably bright DSOs you'll be in for a treat compared to what is visible through the eyepiece. We'll be keen to here how you go.

[Willow127mm (Brad)]

Thanks mate yeah I don't mind being patient and learning I just don't want to make life even more difficult than need be I was trying to get image's with a Macc cass in the beginning and that was incredibly difficult.
But it did teach me some patience.
I hope a EQ 6 will at least help with the tracking side of things as I was using a alt az goto with little luck.
But it is as you say a learning experience.
Thanks to everyone who has taken the time to help me out so far I'm very grateful and overwhelmed with all the posts on this thread.
I had no idea there were so many kind people willing to take the time to help a newcomer.
Cheers Brad

[raymo]

Your are laughing. You are gaining on two fronts. Your F8.3 is much faster than your Mak was, and it still has enough focal length to make
it worthwhile imaging some of the smaller DSOs. Off the top of my head
I imagine that it will require subs of around the same duration as an 80mm f/5 on any given object, but will have better resolution due to it's larger aperture. The CA will be a bit less noticeable, but you really need
f/11 or more to make a big improvement.
raymo

[ZeroID (Brent)]

Off and rolling ! The bigger nebulae will work in that and fill the fov, M42, Eta Carina, globs, 47 Tuc, Omega Cent etc etc. Plenty of sizeable targets that are also bright enough to be a good workout for that combo.
Also if you get a cheap webcam and a 2 x or 3 x barlow planets become an option, possibly some brighter galaxies, Sombrero or Sthn Pinwheel are acheivable.

My current EQ6 load is the Lunt 102 ED f7 as imaging, an 80 f5 achro for guiding and an 80 f11 achro for viewing and checking the target. Long term an 120 f8.3 is workable for those options and will always be a great grab and go regardless.

Now the hardware collection really begins ... . You'll need a guide scope setup soon and then a .....

[Willow127mm (Brad)]

Thanks Raymo, Brent I'm really glad it's looking like a good choice.
I have a 70mmx500mm Saxon frac as my guide scope and a DSLR so need to start looking for a guide camera now Among other things.
I still have the last two payments to go on my mount before I can start thinking of guiding.
I'm sure setting up a EQ mount will keep me busy for a while so plenty of time to save up.
thanks again for everyone's help I can't wait to post my first image.
Cheers Brad