Guide scope for Bresser Mikrokular and 130PDS?

[BrendanC]

Hi all,

Title says it all really!

My next big step is to think about guiding.

I have a Bresser Mikrokular which I initially used for imaging, but now use a DSLR instead. I know that the Mikrokular is picked up by PHD2, so if at all possible, I'd like to use it as a guide camera, with my Skywatcher 130PDS, which has a focal length of 650mm, mounted on my NEQ6.

So, does anyone have a recommendation for a suitable guide scope with this combination of camera and scope?

Thanks, Brendan

[rob_r]

Considering the same for my Mak 127. I don't know much on this but I have read that the ratio between imaging and guiding needs to ideally under 4 and came across this Google Sheet will calculates this, https://docs.google.com/spreadsheets/d/1jd9BPWaonZDCWXJVYFT3v0_pQX03QxPfceWfx0M_8G0/edit#gid=0. There is this too, https://astronomy.tools/calculators/guidescope_suitability.

[BrendanC]

Thanks for this, I don't seem able to access the Google Sheet.

I just gave the calculator a go and it looks like I'll be fine with pretty much any focal length above around 80mm.

So, this is good. But it would be great if someone else actually had experience of using this camera with a guidescope. I've looked and can only find a couple of mentions of using it for this, none of which actually yielded answers. I guess that's a kind of answer though (ie 'no'), but it just seems that, given I already have this camera, and I never use it, and it's recognised by PHD2, then if I could use it, I would like to!

 

Edited June 12, 2020 by BrendanC

[The Admiral]

You could also look at http://astronomy.tools/calculators/guidescope_suitability on the FLO website under astronomy.tools

Ian

[BrendanC]

I did! As per previous post. 

It would just be good to know if anyone actually has experience of using this camera for guiding. Theoretically it should work. 

[alacant]

3 hours ago, BrendanC said:

guide camera

Before you buy a guide telescope,  try with your 130. Attach the camera and see how many stars are visible with a 2 second exposure. I've a feeling you're gonna need something more sensitive.

Cheers

[The Admiral]

29 minutes ago, BrendanC said:

I did! As per previous post. 

It would just be good to know if anyone actually has experience of using this camera for guiding. Theoretically it should work. 

Ah, sorry, I didn't read the thread carefully enough.

Ian

[BrendanC]

1 hour ago, alacant said:

Before you buy a guide telescope,  try with your 130. Attach the camera and see how many stars are visible with a 2 second exposure. I've a feeling you're gonna need something more sensitive.

Cheers

I think you could be right. But, if that's the case, why does PHD2 recognise the camera? It's advertised as being suitable. I'd just like to know if anyone else has used it for this, and with what degree of success. Perfectly prepared to be told it's unsuitable, but it would just be such a pity not to use it if in some way it could work. But yes, you're right, that's probably the best test: see what I can see through the actual scope first.

[aknaggbaugh]

On 12/06/2020 at 19:49, BrendanC said:

I think you could be right. But, if that's the case, why does PHD2 recognise the camera? It's advertised as being suitable. I'd just like to know if anyone else has used it for this, and with what degree of success. Perfectly prepared to be told it's unsuitable, but it would just be such a pity not to use it if in some way it could work. But yes, you're right, that's probably the best test: see what I can see through the actual scope first.

@BrendanC did you ever get guiding working with the Mikrokular? I'm in need of a stopgap guide camera so don't want to spend more than I absolutely have to, and that seems to be the cheapest possibility but I'd like to know if it works before I buy one.

[AstroMuni]

On 12/06/2020 at 14:49, BrendanC said:

Hi all,

Title says it all really!

My next big step is to think about guiding.

I have a Bresser Mikrokular which I initially used for imaging, but now use a DSLR instead. I know that the Mikrokular is picked up by PHD2, so if at all possible, I'd like to use it as a guide camera, with my Skywatcher 130PDS, which has a focal length of 650mm, mounted on my NEQ6.

So, does anyone have a recommendation for a suitable guide scope with this combination of camera and scope?

Thanks, Brendan

Hi Brendan,

I have a scope with similar focal length/aperture (650/130) and I bought the Astro Essentials 32mm guidescope just last week to go with it. Works well ( I tried guiding & platesolving) during the one night that I managed to get with clear skies. I use the ASI224mc on main scope & ASI120mm mini on guider. The suggested ratio (based on lots of reading up 🙂 ) is 5:1 FL between main & guide, hence went for a guidescope of around 130mm FL.

Edited November 10, 2021 by AstroMuni

[BrendanC]

@aknaggbaugh I decided against trying in the end. I figured learning to guide would be hard enough without relying on kit that may or may not work.

In the end I went for a Datyson T7C which is a ZWO ASI 120MC clone, and even uses the same drivers. I got mine from AliExpress for around 75 quid but what with one thing and another, they're more expensive now. Just do a Google search and see what you can find. Here, I've even done it for you: https://www.google.com/search?q=datyson+t7c&oq=datyson+t7c. The mono units are very scarce currently.

It seemed the best value cam that would work with my system and I'm pleased to say it's worked really well. I would occasionally get a 'split screen' effect with it, in that the left and right sides of the image would be swapped for some strange reason, but it didn't affect guiding at all. The reason I got the colour version was that I could guide with it, then remove it and do planetary, but what I found was that, in practice, it's such a pain having to refocus and recalibrate in PHD2, that I just didn't really get around to doing much planetary work and would leave it in the guidescope.

I recently got a dedicated mono camera (a QHY5L-II mono) for dedicated guiding, but haven't got around to using it yet. I would also question whether it would be sensitive enough for off-axis guiding. It's definitely fine for use with a guidescope though.

You could still give the Bresser a go! I've been tempted since but as I say, once the guiding is working well, I'm very hesitant to start fiddling with it.

Hope this helps.