It's likely that this weekend I'm going to get first light on my new f/5 refractor. Although I've only been doing AP for a short time, I feel I've achieved some reasonable images with my f/10 SCT. By no means am I planning to completely give up on the slow scope, but for now my concentration will turn to the new one.
I'd like to ask you all to post any small aperture f/10 images you have in your stock piles just as a comparison for me to see how much more can be achieved. Mainly looking for DSOs as this is what I concentrated on.
Does drizzle integrated F/5 images count? If so.... Eagle Nebula
It is taken with a 5.1" F/5.2 refractor but drizzled so at an image scale of a F/10.4
I'm going to have to say no. Although you " technically " although cleverly for filled the f/10 brief, I can't reflect on your refracted photo lol. I am in absolute awe of that image though Atmos and I'm glad you posted it.
That's a shame. I have a shedload of drizzled images @ f/4.9 I have some at f/9 too, though with 300mm aperture. f/10 is pretty tough unless you have *big* pixels or you're chasing bright targets like the moon and planets.
Once I finish working on my current project I plan on installing the corrector into my 10" which will make it a 10" F/10. Even then I'm probably not fulfilling the "small aperture" part so well
So instead, attached is a 4" F/36 with a Nikon D810 untracked.
That's a shame. I have a shedload of drizzled images @ f/4.9 I have some at f/9 too, though with 300mm aperture. f/10 is pretty tough unless you have *big* pixels or you're chasing bright targets like the moon and planets.
Hi Rick,
This is the challenge I've been facing, I've loved the challenge and capturing objects I shouldn't be in light polluted skies and for sure I will return to the challenge along the way. I think I've captured some reasonable images but I'd like to directly compare with others.
This is the challenge I've been facing, I've loved the challenge and capturing objects I shouldn't be in light polluted skies and for sure I will return to the challenge along the way. I think I've captured some reasonable images but I'd like to directly compare with others.
I think you'll find f/5 a lot more fun, Ryan. Slow f-ratios have their place but probably not a great place to start
Once I finish working on my current project I plan on installing the corrector into my 10" which will make it a 10" F/10. Even then I'm probably not fulfilling the "small aperture" part so well
So instead, attached is a 4" F/36 with a Nikon D810 untracked.
I'd take your 10" f/10 Colin, maybe it's not the smallest apature but I said shows ya 10s and you'd have a pair
Some really nice images there Kevin. No doubt aperture makes a difference but hat I'm learning from your tech cards is that I'm intergrating about 1/2 what you have.
Thank you for sharing with me
P.s. - can you tell me how you get defraction lines in your images ? Do you have a spider mask or something ?
Thanks Ryan. With the M16 image I used Noel Carboni's astronomy tools actions for photoshop. It's a plugin that has a few processing routines. Star spikes is one of them. I don't use that routine often but I did with that image.
F10 is slow going, hence the need for long total integration times. I think for most objects 10+ hours at least. I've discovered 2000mm (8") F10 shows more structure in objects than my 1000mm (10") F4 Newtonian. I originally got the 8" F10 SCT for planets but find myself preferring it for bright DSO's.
Thanks Ryan. With the M16 image I used Noel Carboni's astronomy tools actions for photoshop. It's a plugin that has a few processing routines. Star spikes is one of them. I don't use that routine often but I did with that image.
F10 is slow going, hence the need for long total integration times. I think for most objects 10+ hours at least. I've discovered 2000mm (8") F10 shows more structure in objects than my 1000mm (10") F4 Newtonian. I originally got the 8" F10 SCT for planets but find myself preferring it for bright DSO's.
F/10 was a small step up for me after starting with an f/13 4". I'm looking forward to seeing what my new f/5 will bring but I think the challenges that I set myself up with have actually inpired me more and I've really enjoyed the challenge of capturing objects that I can barely even see the stars around visually.
With a cheaper F/5 refractor colour correction is not going to be great. This means that you’ll have a lot of chromatic issues (purple halos around stars) but it also robs contrast out of what you’re imaging.
This isn’t to say that you cannot have a lot of fun with it and it can be a great learning experience but it certainly has its limitations.
With a cheaper F/5 refractor colour correction is not going to be great. This means that you’ll have a lot of chromatic issues (purple halos around stars) but it also robs contrast out of what you’re imaging.
This isn’t to say that you cannot have a lot of fun with it and it can be a great learning experience but it certainly has its limitations.
I'm not expecting miracles from the f/5 but it will be something different to give a go. Another IIS member has offered me his short newt too when I'm ready so I'll have another option. Everything at the budget end of the market is going to have its limitations but I'm ok with that for now while I'm still learning the ropes.
I used to experiment with a 120mm F5 achro refractor for imaging. If the stars are not too bright in the field you can get away with it. But something like the Orion nebula with bright field stars was horrendous. With OSC anyway. A mono cam and RGB filters help a bit if you refocus between filters, but I noticed the blue channel was still bloated. Maybe with a Semi-Apo filter it would have been better. In narrow band they work fine.
I have some at f/9 too, though with 300mm aperture. f/10 is pretty tough unless you have *big* pixels or you're chasing bright targets like the moon and planets.
