Webcam choices for xmas

[doctortim]

Hi,

I have a Skywatcher Skyliner 200p Dobs which I've had for a couple of years. I'd  like to start some astro photography and am thinking about asking santa for a ZWO ASI120MC.

So first question, will it just 'work' out of the box by using it instead of an eyepiece?

Second question, is it worthwhile? I know I'm limited by the lack of a tracking mount but I'd like to get some decent images of the planets and possibly some of the brighter dsos that I can see with the eyepieces. I'm imaging I can use several second exposures for planets and possibly some limited stacking for the dsos.

Am I being realistic? Is it worth the money?

thanks,

Tim.

 

[knobby]

Your best bet is to try a used one and see if you can track by hand for a bit. If it's too hard then you'd not lose much by selling it on again.

But yes , it should be doable and you'd need a laptop to capture the video.

[doctortim]

Thanks Knobby,

I was going to ask santa, so not really an option to try one first. As far as tracking, I was hoping to get away with exposures of a few seconds (planets) or record a video and use the frames for stacking in the case of dimmer objects.

Tim

 

[glowjet]

That`s a big outlay for a camera for you to attempt AP with the Dob. I think you may find the general consensus of opinion, that it is a non starter, other than general snapshots of our close neighbour and some of the Planets, DSO will be regarded as out of the question.

The most common next step forward to AP, with the 200P, a route which many have taken, is to invest in an equatorial mount on which you can mount the tube assembly, such as the HEQ5 and proceed from there.

However, not to be too disappointed with the above comments, one of our members produced a tutorial..... Dob AP Tutorial.pdf  with the 200p Dob, undertaken with a web cam or similar which you may find useful and informative. Hope this helps

[John78]

It should be easy to shoot the planets - you just need to keep it somewhere on the screen, which is like trying to keep it in a 5mm eyepiece sort of challenge - the post processing tools sort out it moving all around for you (PIPP).

DSO is going to be a whole different kettle of fish they're much bigger generally and fainter and a 200P has a 1.2m focal length and the sensor is tiny... Heres how M33 would look ...

https://astronomy.tools/calculators/field_of_view/?fov[]=1||7||1|1|0&messier=33

Its not just tracking a DSO that will be the problem.

[DorsetBlue]

1 hour ago, doctortim said:

Thanks Knobby,

I was going to ask santa, so not really an option to try one first. As far as tracking, I was hoping to get away with exposures of a few seconds (planets) or record a video and use the frames for stacking in the case of dimmer objects.

Tim

 

I think you would be better asking this question on the Video Astronomy forum, as we are using such cameras without tracking for Electronically Assisted Astronomy (e.g. I use a Altair GPCam 2 for Messier DSOs on a Alt Az Goto). Although as stated above, Field of View can be an issue with large pixel cameras, as can focusing on reflectors.  I imagine it could get quite frustrating.

[doctortim]

22 hours ago, glowjet said:

That`s a big outlay for a camera for you to attempt AP with the Dob. I think you may find the general consensus of opinion, that it is a non starter, other than general snapshots of our close neighbour and some of the Planets, DSO will be regarded as out of the question.

The most common next step forward to AP, with the 200P, a route which many have taken, is to invest in an equatorial mount on which you can mount the tube assembly, such as the HEQ5 and proceed from there.

However, not to be too disappointed with the above comments, one of our members produced a tutorial..... Dob AP Tutorial.pdf  with the 200p Dob, undertaken with a web cam or similar which you may find useful and informative. Hope this helps

I would love a better mount, but £800 is way more than I can justify. I appreciate the advice though.

I've read the pdf which looks useful and similar to other guides I have read. I would hope I could manage improved image quality compared with a modified pc webcam. I was thinking of going down that route but needed to come up with xmas ideas and the ZWO looked about the right price.

[CraigT82]

I'd say go for it.  It's definitely possible to get half decent images Mars, Jupiter and Saturn using an untracked dob.  With a bit of practice you can let the planet drift across the sensor, nudge the scope, let it drift etc... and you can build up lots of frames to center and stack. 

As for taking any pictures of DSO... You can try but don't get your hopes up.  Several seconds untracked at 1200mm will give severe star trailing.  And the tiny sensor wont help either.  You may have some success with say 1 sec exposures of the smaller brighter ones (M57 etc...) but the real hard part will be swapping out the EP, putting in the camera and knowing when you've got the target on the sensor, finding focus etc...  before it drifting out of the FoV.

[doctortim]

47 minutes ago, CraigT82 said:

but the real hard part will be swapping out the EP, putting in the camera and knowing when you've got the target on the sensor, finding focus etc...  before it drifting out of the FoV.

Won't I be able to see the images on the laptop? Too dim?

[CraigT82]

Yes very dim on the screen.  It'll help to have the camera and eyepiece parfocalised so you know it's in focus when you swap the EP for the camera. You'll need the gain turned right up and long enough exposure to see the object and centre it on the screen (or move it to the edge so it can drift across, if there's bright stars near to it they'll help you line it up as you'll be able to see them on the screen nicely. Remember you'll need to do this before it drifts away, and the chip is very small in the ASI120 so you'll have about 20-30 seconds before it's gone.

 

[cjdawson]

Here's my thoughts.

Lunar, solar and planetary should be in grasp with your setup.  Forget about the DSO's, without tracking you'll be severely limited in what you'll accomplish.   There are people who can get results but be warned that's not for the feint hearted.

For Lunar and planetary, you'll most likely use the camera to produce an AVI file, which you'll then be able to pump through something like registax.   Throw away the worse 20% of the images (maybe more) and you should get some good results.  when I say 20% of the images, I mean of your video file, which is likely to contain over 2000 images at a time.  (Keep your video files limited to 2GB as some processing software cannot cope with larger files)

Nothing stopping you from taking lots of image sequences and combining them though ;-)

 

[doctortim]

Really good advice. Thanks everyone. I'm going to give it a go.