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My 1st Widefield Images

Radders

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Radders

Radders

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Got myself a Canon 700d the other day, got home and took these. The 1st image is a 25 sec exposure @ iso 400 and the other is 20 sec @ iso 1600. Tweaked slightly in Lightroom. Taken with the kit lens and tripod.

Just feeling my way round the camera but very happy so far. Just need a wide angle lens and a something like a Vixen Polarie and I'll be even happier!

Paul

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jambouk

jambouk

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Tips!?! Just a lot of trial and error :)

There is a guide to taking star trails I wrote for my astro society, link here:

http://nottinghamastro.org.uk/?page_id=1201

Star trails are relatively easy, even from a moderately light polluted back garden, it's just a case of getting the settings right. Here is one i took the other night when on holiday in north wales:

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The other thing i'd think about is some form of light Pollution filter if you are going to be doing all your imaging from home. There are two main ways to use these, either screw it onto the lens, or nosepiece if you are using the camera at prime focus, or clip it inside the body of the DSLR. There are many types Of filter material, ranging in cost from £10 to several hundred. I use mainly a clip filter which slots inside the camera, an astronomik cls one, not cheap but good. Defo do lots of research first before buying one though - as you'd expect, the ones at the £10 end of the range aren't as effective as those at the £300 end, so don't be tempted to think you've found a bargain if you do see one for £10.

A winder angle lens would be good. Ideally prime lenses are the best as they result in the least amount of aberration compared to zoom lenses, and they usually are faster (having lower f/ values). Again there is a massive range to chose from. A whole other topic. The Samyang ones are nice and priced in the £200-300 range but to get the most benefit from them you would want less light pollution and/or a LP cut filter. There are some wide angle zoom lenses, like the Tamron 10-24 I have and that is handy and has severed me very well for the last 5 years or so. Don't let me earlier comment about zoom lenses put you off them, it is simply a consideration to factor in. When imaging with lenses, it is advised to stop them down one or two stops, as they reduces aberrations at the edges of your images, so if the widest a lens goes is f/2 say, stop it down to f/2.6 or f/3 or whatever the values are.

A single 2 minute image i took with the 14mm samyang the other night with the camera mounted on my EQ mount, unguided, north wales:

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It's tempting to whack the ISO up to the max, but as you'll learn, higher ISO doesn't really mean higher sensitivity of the sensor, it is a complicated area and means the higher the ISO, the higher the noise too, so images can become grainy and look unpleasing. But at the same time don't have ISO too low. Clever people work out what the optimum ISO is for each camera, no idea how (i'm more hands on and learn from trial and error than academic), but with a modern dslr like yours I suspect if you are just going for nice images and not trying to win astrophotographer of the year then ISO 1600 should be ok, but again with light pollution (LP) you may have to drop this to ISO 800 or less depending on your other exposure settings.

If you are new to dslr inaging full stop, i'd consider going on an camera workshop, a day with an expert on how to get the most from your camera - it will be 99% based on day time photography but you'll learn your way around the camera a bit better and learn how to use some of the features and understand dslr basics a bit better. Else if you have a mate who is big into cameras, ask to spend a few hours with them on a walk or something to get a good understanding of exposure settings and framing, focus, depth of field etc. Then do another session on processing.

There are many good books, i'll try and make a list shortly.

Attaching the camera to the scope is a brill idea. What sort of mount do you have? And what sort of scope is it? Depending on the answers to these, will determine how to attach the camera, but probably a nose piece will do the trick. Something like this:

http://m.ebay.co.uk/itm/T-T2-Ring-for-Canon-EOS-Camera-Lens-Adapter-1-25-Telescope-Mount-Metal-DC615-/371353912613?nav=SEARCH

But you might benefit from a 2" nose piece and not a 1.25" like this one, again depends on other issues.

If you have an alt--az mount, your exposures will be limited to seconds, again it will be trial and error, and also depends on the focal length of your scope. If you have an EQ mount, then maybe 30-60 seconds unguided, again depends on many factors. But even if you can only take 4 second exposures, you will be able to take 1000 of them and stack them together and get a nice image. Does the 700D have a built in intervalometer? I suspect not, so you'd need to either control the camera from a PC using eos utilities or some software which you buy a license for like "back yard eos", or just but a cheap intervalometer off ebay like this one:

http://m.ebay.co.uk/itm/Timer-Lapse-Remote-Intervalometer-for-Canon-EOS-700D-650D-600D-550D-500D-UK-sell-/291309580262?nav=SEARCH

Don't click buy now as i didn't check its specs out, was just the first one i saw. Again need to do some research and ask more questions (of yourself or on here). There are wireless versions, but to be honest i use my wireless one wired as its just easier to always know where it is!!! If you want to do star trails you'll need an intervalometer anyway.

Tripod - guess you probably have one, but if not worth getting one. The £20 ones are often poor and very unstable, but you could find a nice one for £50. Charity shops near me often have reasonable ones for a fiver or tenner, but then i live in a posh ish area of nottingham - i think i lower the tone :)

Lots l learn and think about. Keep asking the questions and doing the research. I'll compose a list of books and post them in another reply.

James

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jambouk

jambouk

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Right, rather than re-looking for the books, I've found various old threads for you to read through:

http://stargazerslounge.com/topic/240886-completely-lost/?hl=%2Bwidefield+%2Bbook#entry2613999

http://stargazerslounge.com/topic/249410-dslr-widefield-where-to-start/?hl=%20widefield%20%20book

http://stargazerslounge.com/topic/210278-widefield-dslr-1st-attempt/?hl=%2Bwidefield+%2Bbook#entry2244297

http://stargazerslounge.com/topic/208593-newbie-question-on-tracking-mountdslr/?fromsearch=1

James

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jambouk

jambouk

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The Robert Reeves book on wide-field astrophotography was written before the digital age of cameras took off, so there is a chapter on developing film and stuff, but most of the rest of the book is relevant in terms of exposure and framing and the like and is a real gem, i love it. Looking on Bookbutler, there are second hand copies for about £12 which includes P&P. If £12 is not a massive amount of money to you, I'd get a copy and spend one Saturday afternoon leafing through it:

http://www.bookbutler.co.uk/compare?isbn=9780943396644

The other book I rave about, and anyone would think I've got shares in it is the one by Michael Covington, but I can only find that for £16 - if you want I can post you mine and you can send it back once read:

http://www.bookbutler.co.uk/compare?isbn=9780521700818

The Covingtonbook is more aimed at the digital camera user who is setting out in imaging in astronomy; if you have a comprehensive understanding of the night sky, the celestial sphere, field roation and the like, it might have less impact for you, but otherwise it is a cracking read from cover to cover.

James

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Radders

Radders

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Thanks for taking the time to write all that info James. Much appreciated. I'm definitely a beginner with a DSLR! That's a fantastic shot of the Milky Way. I would like to get something like that.

Got a decent Manfrotto tripod with ball head. An intervalometer on my list of things to buy along with a T-ring. I'll definitely look at LP filters now.

It's an alt-az Nexstar tracking mount and the telescope has a long focal length so I'll have to see how things look with the camera attached.

If your sure about lending the book, I'll pm you my address.

Thanks again.

Paul

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jambouk

jambouk

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The other thing i forgot to mention, is dew. You'll need to sort out some form of dew management system, a band around the front of the scope to put some warmth into the lens and stop it dewing up. If you are good with electronics you can build your own dew controller and even dew bands - there is info out there on this.

Yes i can post you both books. Send me a PM.

Look forward to seeing some more of your widefield images.

James

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