Astrophotography with Eyepieces

Me and my dad have a Celestron SP-C6 and I'll either be using my Canon 300D or Canon 1D Mark3 to take photos. I was wondering to get close up photos of Galaxies and Nebula's like I've seen on the forums, what eye pieces should I use. We only have 3 eye pieces. We have a 4mm, 10mm and a 26mm, my dad use to have a 40mm but we can't find it.

devildog2222 wrote in post #11017453
Me and my dad have a Celestron SP-C6 and I'll either be using my Canon 300D or Canon 1D Mark3 to take photos. I was wondering to get close up photos of Galaxies and Nebula's like I've seen on the forums, what eye pieces should I use. We only have 3 eye pieces. We have a 4mm, 10mm and a 26mm, my dad use to have a 40mm but we can't find it.

I'm a bit of a newb at all this, so more knowledgeable people than I will correct me, but I think that taking photos like we see in the forums requires more than just the camera and the scope. This would be OK for mono images, but I believe the multicolour images are taken through different filters and then combined.

To take photos, the camera is either mounted directly in the focus tube with a "T mount" adapter (this is called "prime focus"), mounted on the end of a "barlow" (akin to a teleconverter) of usually 2x or 3x magnification, or is used with a "projector" eyepiece (haven't quite worked how this one works yet )

For normal viewing, your set of eyepieces seem to cover most of the range, with perhaps a longer one for wider angle view.

Martyn started ya off pretty good, but there a little confusion.

The 25mm, 10mm & 4mm EPs you have will give you 60x, 150x & 375x magnifications (respectively).
I think a 6" is good to about 350x, so a 4mm EP is about as small as your gonna be able to use.

Yes, adding a barlow will gain magnification, but it won't always be able to give you any more details.
A 2x Barlow would give 120x & 300x viewing options for the 25 & 10mm EPs.
Using it with the 4mm would get 750x, but the visual quality would drop big time...
like blowning up an already blurry image.

For EPs, I have a 40, 32, 26mm & 2x Barlow in 2" ,
an Orion 13mm that fits 1.25"/2",
and a 25mm, a 24-8mm & a shorty 2x Barlow in 1.25".

I use my 2" EPs most often. The 40mm is nice for wide views and I use the 26 with the 2 inch 2x Barlow for "closeup".

Viewing & Astrophotography are slightly different.
Switching from one to the other is not simply swapping 2 parts; it will always require a refocusing of the scope. ((This is due to the difference in distance between where your eye would be and where the camera's sensor is located. There is a way around that problem with a little device known as a parafocal unit.))

I'll tell you right now that just viewing nebulas will probably be rather disappointing; they're just grey misty blobs when seen with an EP.
There's not enough photons striking your retina for you to get the colours. Your cameras on the other hand, will see many of the colours. To get the widest color spread, you'd need to modify the camera. (It's a bit of a tricky proceedure & it makes the camera all but unusable for anything except astro work.)

You can take photographs through an eyepiece. That's known as the Afocal method and it's usually done with a P&S camera. Photos done this way include the magnification factor of the EP. The down side is photos also include all of the visual effects of looking through many extra layer of glass.

The photos on here are usually done using the Prime focus method. (In a nutshell, it means the camera physically replaces the eyepiece.) For taking pics that way, you'll need a EOS compatible T-ring & a downtube that matches your size of visual back (with a C6 - it's most likely a 1.25" )

Oh yes... one other thing. Remember: At the distances these are focused, even the slightest touch is a blur in the making, so you'll also want some kind of remote if you want to do Bulb mode or to be able to connect to a computer for taking your shots.

Hope that helped a bit.

^^
In addition, the SP-C6 comes on a rather modest looking wooden mount, and the Eq. mount plus scope look like a real load for it. I don't think that you'll get very satisfactory images of the objects you allude to using either eyepiece or afocal projection. Have you considered an adaptor to allow prime focus imaging? At f/5 the scope would be pretty good for some short, guided shots of the likes of Andromeda and Orion Nebula (maybe, again, that mount!). Of course, it'd be OK for the moon, Jupiter, perhaps even with the eyepiecis.
Am.

MyLookingGlassEye wrote in post #11033782
The photos on here are usually done using the Prime focus method. (In a nutshell, it means the camera physically replaces the eyepiece.) For taking pics that way, you'll need a EOS compatible T-ring & a downtube that matches your size of visual back (with a C6 - it's most likely a 1.25" )

Yeah I already have the T-ring and a Orion Combined Camera Adapter 1.25, which I guess is the downtube your talking about.

ameerat42 wrote in post #11034257
^^
In addition, the SP-C6 comes on a rather modest looking wooden mount, and the Eq. mount plus scope look like a real load for it.
Am.

Actually the wooden mount is very sturdy and stable. Like my dad says, they don't make them like that anymore.

devildog2222 wrote in post #11039493
Yeah I already have the T-ring and a Orion Combined Camera Adapter 1.25, which I guess is the downtube your talking about.

Yep. That's the ticket!