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View Full Version here: : Webcam, CCD or DLSR for beginner on $500 budget?


dulwich.hill
04-06-2010, 11:57 AM
Hi Everyone,

My son and I are thinking of trying some astrophotography. We are looking to do something basic so that other family members can see why we spend hours at night in the backyard as soon as the stars are out!

My question is: if we had a budget of $500, what camera and accessories should we buy to get into this hobby?

The moon and planets would be our first targets, followed by bright nebulae like Orion. A galaxy would be an added bonus (but too faint?). Would love to get a good shot of 47 tuc too and have it as a screen-saver!

Should we look at a Webcam, DSLR or a CCD?

We could spend more on a DLSR as it can double as a regular camera (we don't have to "mod" it do we?)

Our current setup is as follows:

* Skywatcher 6" F8 achromat refractor
* Celestron CGEM mount (same carrying capacity as an EQ6 - 40lbs)
* 5mm, 8mm, 17mm, 24mm Baader Hyperion eyepieces (these are threaded for DLSRs already)
* Moonlite 2" Crayford focuser (manual)

Celestron sell the Neximage package for $99 USD at optcorp.com. Sounds very cheap? Most other colour CCDs start at $400 USD. What level of quality/performance do we actually need?

Many thanks,

James

bmitchell82
04-06-2010, 01:29 PM
in this case a DSLR will be your best option, but you will also need guiding, astrophotography gets a bit hairy at times with the amount of things needed to make it so. But its not out of this world so don't get to scared!

a 450d Canon would be a good starting point, you don't need to modify it to make it work, but the modification does allow different light to be captured. good luck and keep asking questions.

dulwich.hill
04-06-2010, 02:20 PM
Why is an DSLR better? Is it because of the higher resolution?

I was considering a Canon 550D for photography and home videos as it can now also take FULL HD 1080p at 30fps, or 720p at 50fps. Is this useful for image stacking?

So why do I need to guide using a DSLR?

...thinking music....

Ah, I think I understand...guiding is required because DLSRs take a single long exposure shot. Whereas CCD can take many frames per second the so that an image stacker software package can remove any image position errors.

If I used a single shot DSLR, what length exposure do I need to take an nice shot of Saturn? Do I really need a guider ? Is a single long exposure shot better than a stacked frames image? Or is this a purists argument (sorry I don't want to start a flame war!!!).

So, why not buy a cheaper and lighter CCD?

With CCDs, do you mount these at prime focus, or can you use an eyepiece? What is the difference? How do they magnify the image? Surely not via digital enhancement?

Lastly, given I have a largish ACHRO refractor, am I wasting my time over instead saving for a smaller APO refractor (eg 80 or 100 mm ED) and piggy backing them? Our mount can handle the weight.

Sorry about the all the questions!!!

Thanks in advance

James

Astrobserver99
04-06-2010, 04:02 PM
For the moon, planets and bright deep sky objects, a DMK21 CCD camera is a good choice...

For high magnification, a Barlow can be used, or with an adapter it can be coupled to a EP.

You should be able to pick up a new one for around $500.00.

Later, you might want to upgrade to a DSLR, which can be used for long exposure imaging of deep sky objetcs. This will require a lot of extra equipment though, including guide scope and camera, software, laptop etc...Probably not recommended as a first step...

If you just want try a few images to practice with and to show your family, a webcam should cost less than $200.00.

bmitchell82
04-06-2010, 09:15 PM
theres no catch all camera sorry for the buzz kill,

if you want to take images of planets. the DMK is a great little piece of kit but they suffer poorly for long exposures they just arnt really cut for it.

A CCD isn't just a vid cam, a DSLR uses a CMOS sensor generally, and a CCD well uses a CCD its the type of sensor.

not to say that a dmk wont capture the photons it just doesn't do it too well at all its kinda a choice of one or the other.

seeker372011
05-06-2010, 10:50 AM
get a DSLR
its just easier to use. The downnside is that unlike a cooled CCD its noisy so you have to shoot a large number of compensatory frames-(darks)-but thats the trade off

you can take happy snaps, deep space objects and through I have not tried it personally yet, record video for planetary work (using EOS Camera movie Record). Sun and moon easy with a DSLR

you may even want to get a used 350D and buy it well enough so its not all that more expensive compared to the alternatives

best of all worlds

you are starting on a slippery slope of course-soon you will wanting to add an apo -an ED80 or 100 or 120 and want to start autoguiding. But till you do so, you can probably get away with stacking a large number of 15 or 30 second frames for the deep space stuff

good thing is you have the mount for all of this

would recommend against a Neximage-think you will soon be wishing you had more than a webcam

seeker372011
05-06-2010, 11:03 AM
there are CCDs and CCDs

for planets you use a webcam or more sophisticated versions like the DMK/DBK and more exotic and expensive offerings that take a large number of images at very short exposures

for deep space you use a CCD-much much more expensive-that are cooled, very sensitive and can go for hourlong exposure or more if you are so inclined-usually people go for 5 to 30 minutes

so for deep space to get these long exposures you need to autoguide-even with the best mount in the world

you dont need to guide for planetary-and sun and moon-work

you also dont need to guide if you go for relatively short exposures of deep space targets-say 20 or 30 seconds and stack heaps (think 50 or 100 or more) of frames
a zillion 1/25 second frames of deep sapce objects wont unfortunately give you the same result as a single long exposure-you just are not capturing enough signal

PS all this is at prime focus

with a DSLR-as I have said earlier you can shoot both . An all rounder may not be as good as some specially designed fit for purpose camera but doesn't lock you in to one specific type of imaging either-and you can always use it for populating facebook if you decide at some stage to go down a particular path

hope this answers your questions

renormalised
05-06-2010, 12:05 PM
You might also want to look at the astronomical video cameras, like the GStar EX...My Astroshop (http://www.myastroshop.com.au/products/cameras.asp). You can use them for both taking piccies and visual observing, via a monitor or laptop. They come in two flavours, mono and colour, and are good little cameras. Especially when you want to show people what you're looking at.

mswhin63
05-06-2010, 03:33 PM
My experience is quite small in comparision, but I have webcam and DSLR. For planetary webcam (or if you can afford it- specialised CCD video) if far superior. Although long exposure DSLR on a budget is great. But on the reverse I found moon imaging is easier with DSLR but with tracking I am sure my webcam could produce really good images, but a lot of fiddling around with processing and things. In all both cameras a a bonus. Can't afford a speciallise CCD as yet but that will be my end item for serious AP along with good tracking scope.

Prime focus Webcam can't easily give you a whole moon shot, that is where the DSLR works better.

My 2 bob's worth

dulwich.hill
07-06-2010, 10:43 AM
Thanks everyone for the valuable feedback!

It sounds like a DSLR would suit me best as it provides an "all-rounder" solution. While I would love to get seriously into this hobby, I just don't have the time at the moment. I will look to doing some basic photography when the seeing is good.

I would be interested in buying a book about astrophotography in order to learn the techniques from first principles. Can you anyone suggest an appropriate book with reasonable technical depth? I see the following advertised on this site: http://www.astropix.com/GADC/GADC.HTM

Anyone read it?

Cheers

James

Hagar
07-06-2010, 06:12 PM
With a budget of $500 I can see no real options other than a DSLR and even that may have to be second hand. Using it with an Achromat you may have to also purchase a -V filter. You will also have to purchase a camera adapter to suit the camera you buy. These items are not a huge expense but will add to the overall cost.

Depending on the targets you pick a web cam would be an option but with the small CCD the field of view will be very narrow and focusing and just finding your target will be much harder. The other problem with a webcam is finding one with a long exposure mod done on it. The standard Philips web cam which lent itself to modification is no longer made and can be difficult to find.

A DSLR gives you the added advantage of being able to be used for family happy snaps.

Good luck with your search for a suitable camera. Sticking with a Canon DSLR will make life a lot easier for you as well.

dulwich.hill
07-06-2010, 06:32 PM
Thanks Doug,

I am thinking of buying a Canon EOS 550D. We already have an old Canon EOS 300 analog camera so we are use to Canons around here.

A 550D body only, will set me back around $750 USD. I think this is good amount to pay as will also be an excellent photo and video camera. I can justify the extra expense because of its dual purpose. I can also re-use the old lens from the EOS 300 on the new DLSR.

The other feature I like about the new Canon DLSR range is the LiveView. I assume using LiveView I will be able to focus on an object using the camera's screen without having hook up a laptop etc? I won't be guiding for now.

I may be able to get away with no buying a T-adaptor as my Baader Hyperion eyepieces are suppose to be threaded for a Canon lens.

Should be a good adventure. Now if the skies will ever clear up in Sydney, I might be able to try something!

Cheers

James

bmitchell82
07-06-2010, 11:48 PM
a friend of mine spotted a 40d body only for under 500 AUD on ebay, worth a look! as the 40d is a step up from the 550d. All my photos are taken with the 40d though it has been modified which lets Hydrogen alpha light though alot more. but without it you can still take images.! Good luck

Terry B
08-06-2010, 09:52 AM
Unless your eyepieces have a bayonet on the end of them they won't connect to a DSLR. You will still need a T adaptor. It has a bayonet to connect to the camera on one end and a 42mm thread on the other end to connect to the scope.
I think the eyepiece connection is to use a camera through an eyepiece. This entails connecting your camera with a lens attached to the eyepiece. This is only used for imaging very small objects like planets. The weight of a big DSLR would put quite a load on a little eyepiece.
For all other imaging the scope is connected to the camera as if the scope is the camera lens with no eyepiece used.

seeker372011
08-06-2010, 05:13 PM
your old canon lenses may not work with the digital slr just a heads up

I think the jerry lodriguss e book would be quite a good introduction to dslr imaging and processing