Astrophotography

[uncle eric]

I am new to astrophotography. We have an EQ6 pro mount and I shoot a Nikon D300. I have had a lot of conflicting advice about which refractor to go for. Which would you go for??

1) Williams Megrez 90,

2) Sky-Watcher Equinox 80 Pro APO

3) Starseeker 100

[GuillermoBarrancos]

I know the Skywatcher Equinox 80 has become almost legendary when it comes to astrophotography.

The William Optics Megrez series are also very fine telescopes.

The starseeker 100 is an achromat I think (?). If so, then not really a good option.

[jgs001]

There are two things you need to think about from an imaging perspective assuming we are talking APO or high quality ED doublet optics (they aren't the same, the APO should by all rights produce better results, but at much higher cost).

1) Focal ratio. The larger the number in the ratio, the longer it takes to capture the same amount of light at the sensor. If I remember correctly, double the focal ratio, quadruple the exposure time.

2) Aperture, which defines the resolving power of the optics. There are all sorts of equations for working this out, which I don't remember/know.

The only thing remaining is which one fits within your budget. The focal ratio on both the WO and SW are about the same. I can't comment on the specifics of the scopes themselves however.

I'm using a Celestron 80ED (doublet) and it's working very nicely.

[uncle eric]

Thank you very much. all gratefully received.

[Digz]

get yourself a copy of Making Every Photon Count, available from FLO (written by steppenwolf from this forum). I was recommended this book and recently finished it. All I can say is it was worth every penny and clearly explains AP and how to get started with a modest setup (most of which you already have)

[Bizibilder]

I'll second Digz's comment - money well spent. The book points out the pitfalls and will save you money in the long run.

[cyclone]

must get this book too, thanks for pointing it out

[Guest]

Hi, and sorry to invade the thread, but I have a question about this book - does it also include info on how to process astro images, and the best ways to take simple photos like optically-unaided star-scapes and afocal photos, or is it mainly photography with a dedicated scope and proper astro-photography equimpent? Thanks.

As for the best scope - I am a simple astro-photographer, and I am having fun taking naked eye-style widefield photos and simple afocal ones with my reflector, so I am sure you'll have a great time with your camera no matter what you go for. I have a Sky-watcher, and the optical quality is fantastic, but that's about as far as my recommendation can go.

[Digz]

Yes the book does talk about processing images and it is written with beginners in mind thus starting with modest equipment but also mentions some of the more higher end equipment requirements.