Finding targets and framing

[tompato]

I'm just wondering if there were any tips to finding targets and framing with a star tracker like the Skyguider Pro and short focal length telescope?

I've previously just had an 85mm lens on a ballhead with my DSLR and so my technique was roughly point it where I think the target is, take a photo, adjust based on star position and then away I go.

However I've just tried finding a simple target with my Evoguide 50ed which is 242mm focal length and using the Dec adapter and after getting used to the weird way you move in RA and Dec to point at your target, I really struggled to find things, even Andromeda (a target I can find in about 5 seconds with a pair of binoculars).

I did the same technique of taking a photo and then checking the stars against an app to see which way I needed to adjust but I got so frustrated with it - I think the smaller view hindered me in matching up stars and getting the app to show a similar magnitude of stars to what I was seeing.

Is it a case of astrophotography being far less frustrating with Goto or are there some techniques to using these manual star trackers with small telescopes?

Edited October 25, 2021 by tompato

[tompato]

Small follow up here, maybe the best option would be to get one of those hot shoe handle grips with lots of 1/4 and 3/8 threads on it and mount a small finderscope or red dot finder to help. Seems like a relatively cheap solution to not being able to mount one to the Evoguide 50ed rings.

[ONIKKINEN]

You could mount a red dot directly to your camera, like this: https://www.teleskop-express.de/shop/product_info.php/language/en/info/p8871_TS-Optics-Red-Dot-Finder-deluxe-for-DSLR-cameras--made-of-metal.html

 

A finderscope would probably be less useful as the field of view would be the same as with the Evoguide 50ED. I think youll get used to RA and DEC movements being weird soon enough and it becomes easier to deal with.

 

For manual framing you do need to recognize constellations and at least the rough area of the target. I recommend using stellarium to find a bright star near your target and frame to that first, this should be eye-ballable. Then slowly move along the RA and DEC lines towards the target taking exposures along the way.

11 hours ago, tompato said:

Is it a case of astrophotography being far less frustrating with Goto

This one is definitely true.

[AstroMuni]

Are you using the Evoguide for guiding and continue image capture with your existing mechanism?

[tompato]

37 minutes ago, AstroMuni said:

Are you using the Evoguide for guiding and continue image capture with your existing mechanism?

I'm using the Evoguide as an astrograph, as the main lens with the EvoFF field Flattener and my Canon 600d. I think it's just the smaller FoV I need to get used to, as I've only used up to a 85mm camera lens up until this point.

[tompato]

40 minutes ago, ONIKKINEN said:

You could mount a red dot directly to your camera, like this: https://www.teleskop-express.de/shop/product_info.php/language/en/info/p8871_TS-Optics-Red-Dot-Finder-deluxe-for-DSLR-cameras--made-of-metal.html

Ah yeah, this looks like something that would be useful to have. I have a Rigel Quick finder thing and contemplated mounting that to the Evoguide but I don't think I would be able to slide it in and out of the rings with that mount on it.

[Tiny Clanger]

There are adaptors available specifically to put a red dot finder on a photo hot shoe , I've not used any, but here are some :

https://www.widescreen-centre.co.uk/blitz-hotshoe-dslr-camera-adapter-for-red-dot-finder.html

https://www.ebay.co.uk/itm/283165189806

I recently bought a Baader skysurfer RDF, and it comes with a range of attachments, maybe one of them might be adaptable ? There's an image here  https://www.baader-planetarium.co.uk/2020/07/09/baader-sky-surfer-iii-now-back-in-stock/ ,

 I'm sure there are more adapers around,  probably 3D printable ones too.

and if you don't already have an RDF, this is one which can be bought as a bundle with an adaptor

Heather

[AstroMuni]

2 hours ago, tompato said:

I'm using the Evoguide as an astrograph, as the main lens with the EvoFF field Flattener and my Canon 600d. I think it's just the smaller FoV I need to get used to, as I've only used up to a 85mm camera lens up until this point.

Then your best option as has been suggested by others is using a red dot finder. I use a Telrad on my scope in case my Go-to doesnt do a proper job 🙂 The Rigel should do the trick. You will need to align it closely with the Evoguide so that what is in centre of Evoguide fov is also in centre of Rigel. Initial alignment can be done during daytime and then fine tune it at night.

[tompato]

2 hours ago, AstroMuni said:

Then your best option as has been suggested by others is using a red dot finder. I use a Telrad on my scope in case my Go-to doesnt do a proper job 🙂 The Rigel should do the trick. You will need to align it closely with the Evoguide so that what is in centre of Evoguide fov is also in centre of Rigel. Initial alignment can be done during daytime and then fine tune it at night.

Yeah, I think this might be the best solution. I notice Scopestuff do a hot shoe adapter for the Rigel mount plate, but I don't think anyone in the UK sells it, so I'll try rigging something up myself 

[tompato]

3 hours ago, Tiny Clanger said:

There are adaptors available specifically to put a red dot finder on a photo hot shoe , I've not used any, but here are some :

https://www.widescreen-centre.co.uk/blitz-hotshoe-dslr-camera-adapter-for-red-dot-finder.html

https://www.ebay.co.uk/itm/283165189806

I recently bought a Baader skysurfer RDF, and it comes with a range of attachments, maybe one of them might be adaptable ? There's an image here  https://www.baader-planetarium.co.uk/2020/07/09/baader-sky-surfer-iii-now-back-in-stock/ ,

 I'm sure there are more adapers around,  probably 3D printable ones too.

and if you don't already have an RDF, this is one which can be bought as a bundle with an adaptor

Heather

Thanks for this Heather, I'll probably grab one of those and mount it if I can't figure out a good way of attaching my Rigel!

[happy-kat]

I use a red dot finder with a flash hot shoe adaptor on the DSLR. Out the box depending on your T ring thickness you may need a spacer to make the 55mm distance required with the flattener you got, I made mine from some plastic I found in the recycling stash.

[rickwayne]

Are you using a  computer to run your camera? If so, look into plate solving. Even without goto, it really helps to know the precise coordinates of the  center of  your field  of  view.