Prime focus vs eyepiece projection

[mitchelln]

Okay, here's one that will no doubt start a lively discussion! Prime focus vs eyepiece projection.

So far I've done all my imaging at prime focus. This results in small images, so I've been cranking up the pixel count by using a 2.25x Celestron Ultima Barlow and an extension tube. This gives me about 3x. Not complaining about that and it gets me results like this:

However, when I look at it through my 8mm eyepiece, Saturn looks absolutely lovely with lots more ring detail. So I think to myself "why can't I photograph that?"

I've just got a Baader Hyperion 8-24 MKIII, which I can attach my DSLR to. I can't help thinking I'll get a better shot of Saturn than at prime focus with a barlow.

Now, the mention of eyepiece projection seems to incur abject horror with a number of people, but why? I guess there is inevitably more light loss, but I'd only try this with the planets and the moon. With DSO's I always go prime focus as I naturally want as much light as possible on the sensor.

I currently use my 7D, as I already have it and I can't afford the serious sensors. I could go webcam, but I'll start another thread about that one!

So, what is the general advice on all this please? I'm sure this will be an interesting discussion!

Thanks!

[razvans]

I currently use my 7D, as I already have it and I can't afford the serious sensors. I could go webcam, but I'll start another thread about that one!

I also use a 7D I only photographed planets 2 times, with a improvised (3 screws in a EOS macro adapter+25mm plossl) eyepice projection but the results are not very promising. I will (hopefully, if weather permits it) use this Saturday a dedicated adapter for eyepiece photography + 6mm Vixen eyepiece.

I hope I will have better results next time

I think the "secret" for good eypiece projection is perfect axiality of scope-->optics--> adapter --> camera(sensor). I think that even a little deviation can degrade a lot the image quality.

[MikeD]

I did a lot of EPP on the moon and planets but have now settled on a 2x barlow and just increase the distance from the chip to barlow to crank up the mag.

Mike.

[mitchelln]

I've got the M43/T2 adapter that attaches the camera straight to the Baader zoom. All a bit weighty though. So I guess everything should be well lined up. I guess the best step now is to try and compare!

[Tinker1947]

Get it all balanced and give it a try, i reserve EPP for double stars, not into planets other than viewing......