Skymax 102 zwo camera :help me choose please

[powerlord]

Hi chaps, so I think I'm gonna dip my foot into ccd waters for tiny targets my dslrs are not really up to - planets, wee dsos, wee galaxies etc.

I've spent all morning reading about the zwo cameras and am barely any the wiser..

seems to me I could go for the 120mc, but putting in a few more bucks for the 224 would probably be worth it.. But the 178 is far higher resolution so isn't that better? Thry all come out as 'good' on the astrotools ccd chooser. I assume its not all pros with the 178 for the extra cash.. Is it far less sensitive? I was hoping not to have to start guiding yet, so for now it's on an eq5 with servo EQSTARPRO mount.

so out of those three.. Will the 178 get me pics of the planets and the odd dso, or do I need to stick with low resolution (due to tracking/high f ration of skymax?!) of 224 or 120?

Stu

[TerryMcK]

The skymax 102 is not really up to planetary. You really need a long focus scope to bring in more than just a round blob.

The worlds your oyster with long focus scope meant for imaging. However like most goods nowadays they are in short, if not zero, supply.

[TerryMcK]

You also will benefit from a better mount and guiding. Astro is not cheap

[vlaiv]

40 minutes ago, TerryMcK said:

The skymax 102 is not really up to planetary. You really need a long focus scope to bring in more than just a round blob.

The worlds your oyster with long focus scope meant for imaging. However like most goods nowadays they are in short, if not zero, supply.

If I'm not mistaken - SkyMax102 is Maksutov 102mm from Sky Watcher and is perfectly suitable for planetary image - but not as much for dso imaging.

1 hour ago, powerlord said:

Hi chaps, so I think I'm gonna dip my foot into ccd waters for tiny targets my dslrs are not really up to - planets, wee dsos, wee galaxies etc.

I've spent all morning reading about the zwo cameras and am barely any the wiser..

seems to me I could go for the 120mc, but putting in a few more bucks for the 224 would probably be worth it.. But the 178 is far higher resolution so isn't that better? Thry all come out as 'good' on the astrotools ccd chooser. I assume its not all pros with the 178 for the extra cash.. Is it far less sensitive? I was hoping not to have to start guiding yet, so for now it's on an eq5 with servo EQSTARPRO mount.

so out of those three.. Will the 178 get me pics of the planets and the odd dso, or do I need to stick with low resolution (due to tracking/high f ration of skymax?!) of 224 or 120?

Stu

Your DSLR is probably going to fare better with maksutov scope than any other cameras you listed.

As I see it  - you have really two options (not mutually exclusive).

1. Use DSLR with Maksutov and do rather long exposures - like at least couple of minutes each. And long total imaging times.

Learn how to process DSLR images in special way (which includes binning) and prepare for the fact that you won't be able to get large images of small objects. When imaging galaxies and planetary nebulae - it is about seeing and mount performance that determines actual resolution of the image. You can make galaxy as large as you wish - but you can't get the detail needed and it will always look blurry that large.

2. Get camera like ASI178mc for use as planetary and EEVA camera.

You'll need some additional gear for EEVA to fully exploit that camera.

Mak is going to produce very nice images of planets and the Moon with said camera. Check out these:

For EEVA style you'll need 32mm Plossl, 12mm C-mount lens and way to do eyepiece projection.

I'm planning to do something like that with my Maksutov, but I have not yet got to it. I did however some tests on the topic, so you can read about it here:

You can also find couple of threads on EP projection in EEVA section that might explain things a bit better.

[powerlord]

ok, I'm more confused now then. astrobin has a few folk using my skymax 102 and the 120mc and getting nice planet shots. e.g.

https://www.astrobin.com/5ufura/?nc=user

Im shooting DSOs mostly with my DSLRs and camera lenses which is working fine for the larger DSOs (I can go up to 600mm on lenses) and I want to keep doing that.

I'm not looking for perfection (as The Lazy Geek on yt would say - Im not a pixel peeper), just looking for a way to image smaller objects with what I've got.

getting 2000+ FL doesn't appear to be cheap, so though its a long term goal, short term, I thought a barlow and a small sensor would get me at least recognisable planet pictures ? astrobin searches seem to suggest that too ?

 

[vlaiv]

17 minutes ago, powerlord said:

ok, I'm more confused now then. astrobin has a few folk using my skymax 102 and the 120mc and getting nice planet shots. e.g.

I'm sorry if my answer caused confusion. As far as skymax 102 and 120mc combination is concerned - I think it will be very good performer and I think that you can get similar images to one I took and provided links to threads.

As far as Skymax102 and 120mc is concerned in role of DSO imaging - well no. It will not work well. You will be very oversampling and if you reduce sampling rate by binning - you'll get tiny images.

ASI120 and 1300mm of FL gives you sampling rate of 0.59"/px - which is fine for planetary - but at least 3 times higher than you need for DSO imaging with 100mm of aperture on EQ5 where you can hope to achieve 1.8"/px.

This means that you'll need to bin x3 and that will make your image tiny 400x300 or something like that.

You can certainly try. I've tried with 8" F/6 and ASI120 equivalent on HEQ5 mount and I got something like this:

But that is x4 aperture at similar focal length and it's not looking all that nice (too much sharpening and denoising) - but M57 is still tiny.

 

[powerlord]

Thanks, I was thinking planetary and stuff like m51? Dso stuff thats bigger, happy with dslr on mak or camera lenses.

And that was what made me think 178 would do a better job? AND if I get a guider later, I could get better stills than with the 120? Or am I still missing something.

Alternatively if I get sell my p200 and replace it with something that gets into that 2k+ FLs that would be an option with a dslr? But that seems like it'll cost a hell of a lot more than 300 quid.

 

[vlaiv]

21 minutes ago, powerlord said:

Thanks, I was thinking planetary and stuff like m51? Dso stuff thats bigger, happy with dslr on mak or camera lenses.

For planetary - sure, for that you need camera with following characteristics:

- high QE

- low read noise

- fast FPS rates

Pixel size is not as important as you can aim for optimum F/ratio by using barlow lens.

In that sense ASI120 is worse choice than ASI178 as later has better read noise and higher QE and faster FPS.

But again - there is ASI224 that is better from both of these with respect to said parameters (and is one of the best planetary cameras out there).

However, things like M51 will be out of reach for such cameras unless you spend very long hours and use large scope.

Here is what M51 looks like with 8" scope and ASI185 - which is larger, more sensitive and less noisy than ASI120

As a comparison, here is another M51 (luminance only) - with 8" scope taken in 2 hours of total integration I believe (certainly not longer than that) - but with serious DSO camera - ASI1600:

From these two images, you can see what difference camera makes - and you want to use worse camera from these (for dso imaging) and put it on scope that gathers x4 less light.

That simply won't work well.

Before you decide to get "serious" scope with 2000+ FL - do take time to understand sampling rate and how it affects image quality. Long focal length scopes can be used to produce really good images - above lum only image was taken with 1600mm FL scope - but you need to pair such scope with appropriate camera and handle data in certain way.

Bottom line - yes, get small camera for planetary with Mak - it's a lot of fun and great learning experience. You can use same camera on larger scopes afterwards and you can use it to guide later.

You can even try to do DSO imaging with it - just don't expect much. This for example was taken with ASI120 like camera (QHY5LIIc - same sensor) and 8" scope:

And again, same aperture size - 8" but proper DSO camera:

 

Edited April 5, 2021 by vlaiv

[powerlord]

Thanks. I've ordered a 224. I like that I can try to use as a guide camera too and learn about that.

Stu

[JunglistRex]

On 05/04/2021 at 18:42, powerlord said:

Thanks. I've ordered a 224. I like that I can try to use as a guide camera too and learn about that.

Stu

How you getting on with it?

I've also got a SkyMax 102 and was considering a 224 for planetary and lunar.

Have done some reading up and think a 2x or 3x Barlow would be useful. Also I believe an IR filter would be useful.

DOes this sound reasonable? Anything else to consider? Thanks

[powerlord]

yup, great camera. used for some DSO too. I got cheap svbony ir filter.

yeh, for saturn/jupiter, I used a 2x barlow with it.

[JunglistRex]

Good, glad you're happy with purchase. Think that's what I'll go for as well.