Astrophotography camera for 102mm Astro-Fi?

[Erskine1980]

I'm sure this kind of question has been asked a thousand times but...

Having wanted a telescope for a long time, and being a bit of of a gimmick/tech geek, I went for a used AstroFi 102 thinking the smartphone control would be ideal. After hitting the usual issues with alignment and droppouts I added a star sense to my kit to make it usable. Now we had access to the sky it wasn't long before I wanted to capture what I could see and share it with my young children who showed wide eyed wonder at just the moon!

I understand I will be limited by aperture and focal length but I want to be able to capture some of the bigger/brighter DSO's as well as the solar system. I've read so many articles and reviews but have only confused myself further. I already have a Nikon DSLR with a fairly fast 1.8f 50mm lens and a decent tripod to match but no other suitable lenses , so am wondering if a tracking mount  (Skytracker maybe?) for this may be better than a CMOS for the scope? 

However, portability isn't an issue as mostly will be in the garden (with light pollution sadly ☹️) and this way I can use my USB3 capable laptop to show the kids a live view too. I was thinking of a CMOS, with a max budget of around £3-400 what would be a realistic piece of kit? I like the look of the ZWO's and the GPCAM290C but not sure if suitable or just wasting money given limitations of my equipment.

With the Star Sense and hand controller also being attached to the 2 ports would this cause an issue too?

Any advice gratefully received! 

Clear skies to all

[happy-kat]

Hi

I'm not particularly familiar with the mount you already have, but it tracks doesn't it? 

Whilst it moves in tiny left right up down movements this is fine for imaging the Moon or planets and useable for DSO if you stick within the limitations this presents with shorter exposures limited by the Earth's rotation which the mount can't track.

[Erskine1980]

Thankyou for this - being limited to 20sec or so exposures presumably would mean better off with a tracking mount for the D3300 instead of a CMOS then?

[The Lazy Astronomer]

1 hour ago, Erskine1980 said:

Thankyou for this - being limited to 20sec or so exposures presumably would mean better off with a tracking mount for the D3300 instead of a CMOS then?

If you are looking to do long exposure photography, then you would need to ensure you were using an equatorial type mount regardless of whether using a telescope or camera lenses. 

What you have currently is an alt-az mount, so you would be limited in terms of maximum exposure time. 

That being said, however, it is possible to obtain very pleasing images with alt-az. Check out this thread for some examples: 

 

 

[The Lazy Astronomer]

Sorry, second post. 

I've just realised your scope is a long focal length mak. This would not generally be recommended for deep sky imaging.

Your stated budget for a dedicated astro camera will also limit you to small sensors, which will make your FOV very small (again, not generally recommended for deep sky imaging).

[ollypenrice]

Rather than put money into the wrong system I would suggest putting it into a system which is right from the outset. (I'll take some persuading that an F13 Maksutov on an alt-az mount isn't about as 'wrong' as it gets for DS imaging.)

You already have a good DSLR and an excellent 50mm lens. Great. You can use these to take images from a fixed tripod provided you keep exposures short and stack a lot of them. Better, though, would be to mount the camera on an equatorial tracking mount. The Skywatcher Star Adventurer would be a good starting point, or you could invest more heavily in a mount that will, in the future, carry a telescope. Brace yourself for the discovery that mounts are of primary importance and expensive.

One of the great things about astrophotography is that it has shown astronomers the truth about the deep sky: it is not only full of small objects to be seen in telescopes but also full of vast, extended structures only visible in widefield photographs. Enter your 50mm prime lens. Here's a great Orion by Stéphane Guisard and Rob Gendler from a Canon Nifty  Fifty. Good, no?

http://sguisard.astrosurf.com/Pagim/Orion_constellation-HRVB-50mm.html

(Sure, this was done with a monochrome CCD camera and filters but you can see the power of the lens. Note that it wasn't used wide open. Stars are very hard for lenses to control and at F1.8 they won't do it.)

Like many others I'll insist that your first purchase should be this: https://www.firstlightoptics.com/books/making-every-photon-count-steve-richards.html  So many aspects of astrophotography are counter-intuitive that a fundamental understanding of the underlying principles is essential in avoiding wasted purchases.

And what's the least useful item in astrophotography? A smartphone. 👹

Olly

Edited February 3, 2021 by ollypenrice

[happy-kat]

The cheapest second go at DSO after the static tripod suggestion above is remove the telescope and instead mount your DSLR and 50mm lens on your tracking mount directly. Aiming East or West is best and keeping below 60° will maximise your exposure length experiment anything from 10-45 seconds keeping an eye on star elongation. Take plenty of raw frames and using free software process what you get DSS and GIMP will start you off and see if you enjoy it and want to investigate more.

If you don't have a remote trigger release for your DSLR then the delayed timer you are likely to have on your camera will help.

[Erskine1980]

Thanks all, I have received and read the book - thanks for the pointer. I'm thinking of changing tack and going for a AVX mount instead. At least that way I can keep using my camera, current tube and star sense as a starting platform for the future.