Can’t see anything with ZWO 385MC

[ThomasF1234]

I have a Sky-Watcher Evostar 102 and I’m trying to take some shots with a ZWO 385MC. I can clearly see stats such as Arcturus and Capella and planets like Venus however, I can’t see clusters such as the beehive cluster. Has anyone got any ideas on how to fix this?

[JamesF]

Could be that you're seeing too small a part of the Beehive to recognise it as such, perhaps?  Testing on some globs might be informative.

James

[Davey-T]

Hi Thomas and welcome to SGL, what software are you using ?

Do you mean Evostar 120 ? even so you'll only get a few central stars of M44.

If you click on resources at the top of the page and choose FOV imaging mode you can fill in your scope, camera and target to see what you can image,

Dave

Edited April 26, 2020 by Davey-T

[JamesF]

30 minutes ago, Davey-T said:

Do you mean Evostar 120 ?

There's a 102 as well, though actually both have the same focal length as far as I'm aware so it doesn't make a lot of odds.

James

[JamesF]

I just worked it out:

The field of view of the ASI385MC at 1000mm focal length is about 0.4 x 0.24 degrees.  To get the majority of the brighter stars of M44 you need a field of view of at least a degree each way, possibly a touch more.  So you could be pointing right at it and not realise because you can only see a few of the main stars.

James

[ThomasF1234]

7 hours ago, Davey-T said:

Hi Thomas and welcome to SGL, what software are you using ?

Do you mean Evostar 120 ? even so you'll only get a few central stars of M44.

If you click on resources at the top of the page and choose FOV imaging mode you can fill in your scope, camera and target to see what you can image,

Dave

 Thanks! I’m just using the software that ASI cameras come with and I also tried using sharp cap but had no luck

Edited April 26, 2020 by ThomasF1234

[ThomasF1234]

6 hours ago, JamesF said:

I just worked it out:

The field of view of the ASI385MC at 1000mm focal length is about 0.4 x 0.24 degrees.  To get the majority of the brighter stars of M44 you need a field of view of at least a degree each way, possibly a touch more.  So you could be pointing right at it and not realise because you can only see a few of the main stars.

James

Thank! How do you change the field of view?

[PeterCPC]

You can only change the FOV by changing the equipment used. In this case you would need to use a different/smaller scope. Check what you need using the FOV calculator in the resources tab at the top of the page.

Peter

 

[ThomasF1234]

17 minutes ago, PeterCPC said:

You can only change the FOV by changing the equipment used. In this case you would need to use a different/smaller scope. Check what you need using the FOV calculator in the resources tab at the top of the page.

Peter

 

Thanks! I have put in my equipment and so on into the calculator and it’s came up with the attached image. What type of telescope would you recommend?

[Freddie]

If you are using a Barlow as shown in the calculator then best to remove that. Also you have it setup for an eyepiece so you should change that over to be your specific camera to get the proper FOV for your setup

[ThomasF1234]

11 minutes ago, Freddie said:

If you are using a Barlow as shown in the calculator then best to remove that. Also you have it setup for an eyepiece so you should change that over to be your specific camera to get the proper FOV for your setup

Thanks! Sorry I didnt realised you could change it for the camera. I have changed the equipment and it shows this:    Also it says the FOV is 0.81 x 0.26

Edited April 26, 2020 by ThomasF1234

[Cornelius Varley]

20 minutes ago, ThomasF1234 said:

Thanks! Sorry I didnt realised you could change it for the camera. I have changed the equipment and it shows this:    Also it says the FOV is 0.81 x 0.26

Somewhere in your equipment selection you have entered a wrong parameter, the pixel size should be 3.75 x 3.75

[ThomasF1234]

7 minutes ago, Cornelius Varley said:

Somewhere in your equipment selection you have entered a wrong parameter, the pixel size should be 3.75 x 3.75

Hi sorry I’ve re done it and got this it says the FOV is 0.42 x 0.24. Is it a case that I would need a guide scope to be able to capture these sort of images?

[PeterCPC]

I put your camera into the FOV calculator for the Beehive with a Skywatcher 72ED and it show this:

If you want a wider FOV you will have consider using the camera with a lens I think.

Peter

[ThomasF1234]

5 minutes ago, PeterCPC said:

I put your camera into the FOV calculator for the Beehive with a Skywatcher 72ED and it show this:

If you want a wider FOV you will have consider using the camera with a lens I think.

Peter

With the instructions that came with the camera it says to take the lens off and doesn’t give any sort of adapter to allow you to use the lens. Would something like this work?https://www.firstlightoptics.com/zwo-accessories/guide-scope-bundle-suitable-for-side-by-side-bars-or-guidescope-mounts.html

[JamesF]

I think you probably have to accept that with your camera and telescope combination, M44 just isn't a practical target.  Something like a 300mm DSLR lens would probably make framing a nice shot much easier.  You can get adapters to fit Canon (and possibly also Nikon) lenses to astronomy cameras, though they're not particularly cheap and if you have a DSLR lens then you probably have a DSLR and it may well be easier just to use that.

Otherwise I'd stick with more compact targets such as globular clusters.  There are a fair few of those to play with around Virgo and Hercules at the moment.

James

[ThomasF1234]

4 minutes ago, JamesF said:

I think you probably have to accept that with your camera and telescope combination, M44 just isn't a practical target.  Something like a 300mm DSLR lens would probably make framing a nice shot much easier.  You can get adapters to fit Canon (and possibly also Nikon) lenses to astronomy cameras, though they're not particularly cheap and if you have a DSLR lens then you probably have a DSLR and it may well be easier just to use that.

Otherwise I'd stick with more compact targets such as globular clusters.  There are a fair few of those to play with around Virgo and Hercules at the moment.

James

I have a Canon EOS and I do have a 300 mm lens. I tried the canon last night however with no lens on through the telescope. Do you mean to put the camera with the lens onto the telescope or just point the camera at the clusters ect with no telescope.

[PeterCPC]

No, I think that you would have to consider a Geoptik adapter for ZWO cameras. As James says stick with more compact targets. I took this image of the Crystal Ball nebula with my 385MC.

Peter

[ThomasF1234]

3 minutes ago, PeterCPC said:

No, I think that you would have to consider a Geoptik adapter for ZWO cameras. As James says stick with more compact targets. I took this image of the Crystal Ball nebula with my 385MC.

Peter

So if I got the adapter and attached the 385 MC to the 300mm lens would I then point that through the telescope or just straight at the target?

[PeterCPC]

Straight at the target. My Crystal Ball nebula was shot using an ED80 telescope.

Peter

[JamesF]

12 minutes ago, ThomasF1234 said:

I have a Canon EOS and I do have a 300 mm lens. I tried the canon last night however with no lens on through the telescope. Do you mean to put the camera with the lens onto the telescope or just point the camera at the clusters ect with no telescope.

If you have a Canon DSLR and 300mm lens then there are a few possible options.

You can use the lens with the 385MC though as Peter pointed out you need the adapter to do so.  You'll also need to focus it manually.  The adapter is (from memory) a shade under £100 new, so unless you're sure you'll get the use out of it then I'd pass on this option at first.  They do occasionally come up second hand, but not that often.

You could put the DSLR on the telescope, which would effectively give you a wider field of view because the DSLR sensor will be much bigger than that of the 385MC (just like a full-frame DSLR gives you a wider field of view with the same lens setup than you'd get with a crop-senor DSLR).  I'm not sure how this would work out.  You may find that there's a fair bit of distortion at the edges of the frame, and it's possible you might not be able to reach focus at all, but the only way to find out is to try it.

The simplest method for this specific target is probably to forget the telescope and just use the DSLR with the 300mm lens.

Except for the bells and whistles, there's really not a lot of difference between a telescope and a camera lens.  They're there to do the same job.

James

Edited April 26, 2020 by JamesF

[ThomasF1234]

10 minutes ago, PeterCPC said:

Straight at the target. My Crystal Ball nebula was shot using an ED80 telescope.

Peter

Sorry for all the questions but did you have the 385mc attached to the telescope when taking that shot?

[PeterCPC]

Just now, ThomasF1234 said:

Sorry for all the questions but did you have the 385mc attached to the telescope when taking that shot?

Yes.

Peter

[ThomasF1234]

7 minutes ago, JamesF said:

If you have a Canon DSLR and 300mm lens then there are a few possible options.

You can use the lens with the 385MC though as Peter pointed out you need the adapter to do so.  You'll also need to focus it manually.  The adapter is (from memory) a shade under £100 new, so unless you're sure you'll get the use out of it then I'd pass on this option at first.  They do occasionally come up second hand, but not that often.

You could put the DSLR on the telescope, which would effectively give you a wider field of view because the DSLR sensor will be much better than that of the 385MC (just like a full-frame DSLR gives you a wider field of view with the same lens setup than you'd get with a crop-senor DSLR).  I'm not sure how this would work out.  You may find that there's a fair bit of distortion at the edges of the frame, and it's possible you might not be able to reach focus at all, but the only way to find out is to try it.

The simplest method for this specific target is probably to forget the telescope and just use the DSLR with the 300mm lens.

Except for the bells and whistles, there's really not a lot of difference between a telescope and a camera lens.  They're there to do the same job.

James

Would it best using a guide scope to help with this or is there some way of attaching the camera to the telescope in order to be pointing the camera in the correct direction

[ThomasF1234]

Just now, PeterCPC said:

Yes.

Peter

Thanks, is that to do with your telescope having a wider FOV