5" Astrophotography - newbie questions!

[Nebulax]

Hi fellas, I'm new to the forums, so give me a warm welcome.

I'm thinking of starting astrophotography soon. I've heard you need an expensive camera though that's able to do long exposures. I've got a pentax digital camera (Model 60S or something like that), a 5 inch newtonian reflector (EQ2 mount and motor drive) and a webcam. Would I be able to start out with that?

Also, I live in Copenhagen, which is fairly lightpolluted. Do you think I will be able to see (not photograph) M51 and M57 from here? Or will that require a dark countrysite?

I really can't afford a camera much over the 300$ limit at the moment. Any advice on decent cameras in that price range?

Any help will be greatly appreciated, thank you!

[rowan46]

Hello and a warm welcome to sgl. the real secret to long exposure astrophotograhy is the mount it needs to have very accurate tracking or be capable of being guided, unfortunately the mount you have is neither. Nethertheless all is not lost, you do have a webcam and pics of planets with a webcam are certainly possible as is pics of the moon. You may be able to get pictures afocally of the moon with your pentax as the moon doesn't require long exposure

[Nebulax]

Thanks for your quick answer.

Ok, well, that sounds cool. Though I thought an EQ2 mount was good enough, at least?

Are there any way of attaching the webcam to the scope, or will I need special equipment?

Also I would love to do photograph some DSO if that's possible. But not with my current mount, or...?

[Cornelius Varley]

You will need a nosepiece for your webcam, similar to this one Adaptors - 1.25" low-profile nosepiece to webcam lens thread (ToUcam 840K) depending on your webcam.

As rowan46 has already started, for DSO imaging the mount is the most important piece of equipment. It need to be able to tracking accurately (ideally have an autoguide port) and have a load bearing capacity of twive the weight of the intended telescope/epuipment it is going to carry.

Peter

[rowan46]

you will need a 1+1/4 inch nosepiece to attatch to the scope. but I'm afraid a half decent photo on that set up is unlikely. you could try anyway you might get lucky.

[E621Keith]

I agree with others on the mount. Most regards a HEQ5 as the most basic equatorial mount for DSO astrophotography. If the mount is of good quality, well polar aligned, well balanced and uses a fast short focal length scope, guiding is not essential if you limit you exposure to less than a minute and stack multiple exposures.

You will need a camera capable of taking long exposure. A DSLR is the entry level camera for DSO. Unfortunately a compact point and shoot will not be suitable. Luckily nowadays, last generation DSLR can be picked up used for a very good price. (D70 ~£150)

My advice is the stay off DSO imaging for now, and get a DSLR and a cheap fast lens (e.g. a nifty fifty). A motorised EQ2 mount should be capable of carrying a small DSLR for imaging constellation sized target.

[david o]

Hi Nebulax,

For astro-photography you'll find the book Making Every Photon Count (by SGL's very own steppenwolf & now onto it's 2nd Edition) helpful in getting started. Easy to read, it's full of advice aimed at the imaging novice, including choosing the right equipment, tips 'n' tricks and lots of other vital stuff.

The imaging section, too, is full of experienced, talented folk who, I'm sure, will be more than happy to share advice and guidance with you.

[Nebulax]

Hi again, and thanks for all your replies, it was very helpful.

I think I'll stay away from the nosepiece for the webcam, and just stick to manual photography untill I've decided which camera to buy etc. A Nifty Fifty you say, Keith. Any advice on which (cheap) camera that would do, as a minimum?

And that Making Every Photon Count sure looks good, but I already have 1-2 books on the subject :-) It's cool though, that he's active on the forums too.

I appreciate your help. Later.

[E621Keith]

A new 50mm f1.8 lens can be found for less than £100, even cheaper if you buy it second hand. When used with a APS-C format (Canon 1.6x) DSLR camera, you get a field 27x18 deg, roughly the size of Orion. If you use a film SLR the field will be even larger, roughly 40x27deg.

You don't need the newest state of the art DSLR, an old Nikon D50 or Canon 350D will do the job just fine. They cost around £120 (used) on ebay.

People use barn door tracker with this camera and lens combination, so your EQ2 will be more than sufficient for the job.

[Nebulax]

Thanks alot for all your replies, very helpful indeed.

I will probably buy a used camera sometime soon then, on Ebay or Amazon or whatever,

I'm not completely sure what you mean though: can you get a 50mm lens for all new / old cameras as well as the 350d for example? (Which is not sold in Denmark anymore, afaik).

And a nosepiece of course. I'd think the camera was too heavy for the scope, but what do I know. >:

Of course planetary imaging would be exciting too, but I think capturing actual DSO's and getting just a bit of colour from them will be much cooler. Or do you think that is out of the question with a 350d / D50?

Sorry about all the questions, but for a newbie, this is very confusing!

[E621Keith]

Sorry, it seems like I've confused you.

The basic astrophotography set up has three components. 1. The mount, 2. optics, and 3. camera. From what I gather in the opening post, you have a EQ2, a 5" reflector and a Pentax compact point and shoot camera of some description.

There are two major problem with your current set up, namely your mount and your camera. First of all, a EQ2 is far too light weight for imaging DSO using a telescope. Then your compact point and shoot will not be able to take long exposure.

There are two solutions, both involve not doing DSO imaging. rowan46 suggested focusing on imaging moon and planets. For that you will need an adapter to connect your telescope to your camera. Something like this Baader Microstage Clickstop digital camera adapter With that you can use the video mode on your Pentax to take a video of moon and planets, then combine the images using Registax to create a final image. Usually this is done with a webcam rather than compact p&s camera. I don't know whether your Pentax has threaded lens so the baader adapter will be a safer option than a threaded adapter.

The other solution to your equipment problem is to do wide field imaging. To do this you will need a camera capable of long exposure (the camera) and a fast camera lens (the optics). In this set up, you will not be using your telescope, but you will be using your EQ2 (the mount). Since camera lens has such low magnification compared to a telescope, there are less demand placed on the mount, long exposure photography become possible. You won't be able to image small DSO, but it will be possible to image the milky way (it's a galaxy so qualify as a DSO ) and constellations.

New DSLR are quite expensive and will cost more than your€300 budget. However, you can get older generation DSLR second handed for around £150. A used Nikon D50 or Canon 350D DSLR will be sufficient. You will need a remote shutter release (e.g. Nikon ML-L3 for Nikon or Canon's equivalent for the Canon)to trigger the shutter in bulb mode (£15). Finally you need optics for your camera to complete the wide field imaging system. I recommend a 50mm f1.8 lens, good quality optics and generally very cheap, both canon and Nikon has one in their range for less than £100 new. The zoom lenses often bundled with these DSLRs are not suitable due to mechanical problem with the cheapest kit lens.

I am not sure how much things cost in Denmark, so I quote UK prices. I doubt there will be a significant in price, since UK and German price (my reference for continental price) seems to be similar.

If your budget is really tight, you can go one step further and get a second hand film SLR. They are really cheap nowadays, you can probably get a one for less than €50.