Astrophotography

[Copernicus]

Telescope + Digital Camera
Hi Everyone,I'm new to this, and have got myself an Optex 8 inch telescope (Newtonian) on an EQ mount. I have a digital Canon 350D camera. What do I need (accessories) to set up my camera with the telescope. Any help would be appreciated it.

[rogerg]

Welcome, from a fellow Perth resident.

First thing I'd recommend is finding a way to mount your camera on the back of the telescope, such that you take wide field photo's of the sky using the camera with it's normal lens, but mounted on the telescope so that it tracks with the sky.

This will be much more rewarding and less frustrating than any "through the telescope" type photograph that will require more adaptors and the rest.

Many of those newtonians come with a standard camera tripod mount thread bolt on the top of their rings that hold the tube. You might have that. If you do, then buying a simple ball joint tripod head, from somewhere like Camera House, will allow you to mount your camera on the back of the telescope pointing in any direction. This makes for easy framing etc.

Then with the camera on the back of the scope, you can guide through the scope.

Not knowing what level you're at, if this is all way too obvious and below you, sorry... it's the first place to start... if so, then it'd be worth going in to what adaptors are required to put the camera looking through the telescope. If on the other hand it all sounds way too confusing, I'd be happy to help you out with it and how you how it's done at an ASWA (http://aswa.info/) event.

The 350D is very capable for astro photography, you should get nice shots quite easily at 30 sec to 1 min exposures, as explained above.

Roger.

[Copernicus]

Thanks Roger,Any help is greatly appreciated here. I'll be more than interested in coming along to one of these events in Perth and getting a hands on explanation. Although if you can explain it to me on this forum the quicker I can get into it. I'd like more of an explanation on how to mount in on the back of the Newtonian. That sounds very interesting and perhaps preferable with my camera lenses i already have.When is the next ASWA event?

[rogerg]

The next event is on Saturday 27th. There's a social arvo/night, viewing and bbq. I believe it's at Whiteman Park, if it suits then I can find out more details or you can enquire through the ASWA website. After that it will be back to the usual: one lunar night and one or two deep sky viewing nights each month.

As for your current situation...

It would be helpful to know if you have a suitable bolt on top of your telescope. Can you post a photo of it to get the ball rolling? They build these things in all different ways and I haven't personally had experience with the Optex ones.

I have attached a few pictures of what I hope you can achieve. They are my small 80mm rings but often even 8" scopes are joined to the mount using big rings like these, so perhaps the theory will be the same.

You can see on top of one of the rings is a bolt. A camera can bolt directly on to that. I put the shown ball joint tripod head on top of the rings instead, and then mount the camera on to the quick release plate of the ball joint tripod head. That way the camera can be pointed independent to the direction of the telescope. Obviously I can't show the camera on there, because it's in my hand.

Perhaps that helps?

If you don't have rings like these (but bigger), there mighte be some other way Optex expected you to attach a camera. Most manufacturers do provide some sort of camera mounting on the telescope, perhaps by way of an optional accessory.

Roger.

[Copernicus]

I have to check that out on the Optex, Its with my brother in law currently as we went halves in this so we both can have enjoyment out of this. If I did mnage to find the bolt on top and managed to attach the camera how is that supposed to work with the telescope concurrently. It seems to me that its only attached and sitting on top of the camera not actually looking through. Sorry to be so daft with this...

[74tuc]

Hello Rodger,

Before you mount the 350 to the 'scope you need to determine if there is enough back focus so that the you can at least focus the image. Many newtonians are not made for astrophotography. Matching the camera to the scope will require a standard T coupling.

The 350D has a reasonably large CMOS sensor so you will need to determine if the field is reasonably flat to do this camera justice.

What is the focal length of the 'scope? Given this number we can work out the image scale and field of view then take it from there.

Rgds,

Jerry.:)

[rogerg]

Jerry, that would be the case for mounting the camera looking through the scope. What I'm suggesting to Copernicus is mouning the camera on top of the telescope, not looking through the telescope at all. There, backfocus isn't an issue.

I think mounting it looking through the scope (using t-ring etc) should be the 2nd or 3rd step, once piggy-back astrophotography has been achieved, seeing as piggy-back is much easier to achieve... But that's just my opinnion.

:)

Roger.

[EzyStyles]

I use to own the same Optex 8" scope until steve pinched it off me. Is yours the F/4 Copernicus? It comes with a 1 1/4" focuser which the 350D wouldn't be able to go in. You won't be able to get enough infocus with the standard R&P focuser. Stick to Rogers plan and go piggy back astrophotography.

[EzyStyles]

forgot to mention, the standard EQ mount doesn't have tracking.. you will need motordrives to do piggy back work.

[rogerg]

ahh, now there's something I didn't think of, a tracking drive - trivial of course :screwy:.

:)

[Copernicus]

I'd prefer to take photos via the telecope lens as my camera lenses are just not powerful enough to take good photos of the sky (all you'd probable see are star dots. I'd like to able to take shots of planets and nebulae. I heard that one can get a t-mount and a lens adaptor and one can fix a 350D to the lens piece of the telescope. Is this true?This is exactly what I have Ezystyles. Can I mount my camera if I get adapters and t-mounts on the below telescope? Or is there a better way.TASCO OPTEX OP600 200X800MM NEWTONIAN EQ TELESCOPE Objective lens: 200mm. Focal Length: 800mm. Focal Ratio: F4. Type: Newtonian Reflector. Eyepieces: 9 and 25mm Plossl. Mount Type: HD Equatorial Mount. Highest Practical Power: 470x. Tripod Type: Aluminium.

[EzyStyles]

Hi Copernicus,

You won't be able to take deep space objects eg: galaxies & nebulas with the mount you have. You need electronic motor drives to track the rotation of the earth. The standard focuser 1.25 inch is too small to put the canon 350d into. t-mount adapters are normally for 2 inch focusers. (correct me someone if i am wrong), plus you won't be able to reach infocus. You will need a low profile 2 inch focuser because the Optex only comes standard with a 1.25 inch R&P focuser. If you are serious into astrophotography work, first thing i will get is a tracking mount eg: HEQ5 or EQ6. If you have standard canon 350d lense eg: 18-55mm, that is good enough to practice with for piggy back widefield work.

[EzyStyles]

here's a picture of the orion nebula with the meade DSI CCD camera wayyyyy back taken with the same Optex 8" F/4 with the EQ mount. no tracking :)

[EzyStyles]

im not really a widefield astrophoto person, but here's a shot with the 350d standard 18-55mm lense piggy back..

http://www.va02.net/~ezystyles/gallery2/main.php?g2_itemId=74&g2_enterAlbum=0

[rogerg]

Copernicus,

I would caution you on having high expectations and starting with the complex aproach, unfortunately astrophotography really is one of the things you should start at the bottom and work your way up to make our life easy and efforts rewarding.

I started through the telescope, and ended up with almost exactly what Eric showed, lines instead of stars, for several rolls of film before I switched to piggy-back.

Another alternative if you want to use your telescope optics is planetary imaging with a webcam, and forget about the 350d. Eric might correct me but I suspect it would be possible to do webcam imaging using a barlow on that scope (the barlow allowing you to reach focus). You might even be able to get away with manually tracking (moving the telescope in RA) for the short duration of videos, but it could be frustrating.

Eric, you can fit a t-ring to a 1.25", you just need the right combination of adaptors :) The camera ends up a few mm further from the scope in addition to the t-ring.

Good luck, and I'm still happy to help at some ASWA event in the future if you'd like to turn up :thumbsup:

Roger.

[Copernicus]

Lucky for me the previous owner of the optex 8" bought an electric tracking motor so at least thats attached and working. Taking advice from you Roger and Ezystyles is very important for me to try different methods. Thanks for your help thus far. As Roger says maybe the t-mount and a specific adaptor might work with the 1.25"(and also the tracking motor as I see your point completely). I will experiment with both methods.

Very nice pics Ezy.

[Copernicus]

Thank you to all who have given me encouragement and imparted valuable knowledge. It is truly amazing to see things for yourself in reality rather than looking at pictures. My first viewing session went incredibly well. Lucky Perth is rarely has cloudy days/nights....apologies to all the farmers who rely on clouds and water.....Saw M42, the moon and Saturn. I'm completely hooked.I do have a question though. What eyepiece can anyone recommend for my telescope. I have an 25mm and a 10mm from Plossl which worked well but I can probably use even a smaller one like a 4mm or a 3.5mm. Can anyone suggest good eyepieces with reasonable eye relief.

[EzyStyles]

I knew that roger :P :P .no worries Copernicus. nice that tracking came with your mount also, but at most, you will probably get 30sec - 1 minute worth exposure on that mount. Its not stable enough for deep space stuff but you might get away with planetaries. To go longer exposure, you will then need autoguiding with a more suitable mount such as HEQ5 or the EQ6 and a guidescope attached with a guide camera. Sorry can't help you out with eyepieces as I'm no expert, but any Televue, Pentax's, or Vixen LV's should do well in that 8" F/4 scope. expect $150+ each for decent quality eyepieces.

gluck

[Garyh]

Hi Copernicus,
I would just buy a good quality x2 barlow like one of andrews or Bintels ED ones. You will be able to use this for imaging as well later on (moon, planets) but make sure it has a T thread for this, some do some don`t.
http://www.andrewscom.com.au/site-section-10.htm (down the botom of page...).
I would not bother to try to image through your scope (prime focus...nebs and galaxies etc) cause you won`t be able to. Like What Eric says that you won`t be able to get your camera to focus even with a adaptor without major modifications, (changing the focuser moving the mirror and cell etc) Maybe later if you are keen enough to pull your scope apart and modify it.
These scopes are made for visual use and not designed for prime focus work. Get a good tripod head and make something up like Roger has mentioned and try some widefield imaging first just with camera lenses. You can use your scope to guide or track and maybe get a good telephoto lense to get a bit closer. You will be suprised in what you can do with a 350d and some good lenses.
Hope this info helps..
Very good advice Roger and Eric!!
cheers Gary..:thumbsup: