Jupiter using eyepiece projection and a QHY5

[cybereye]

Well I'm definitely in the testing phase!!

I quickly set up the scope tonight to try and fill the QHY5 chip with an image of Jupiter. This time, instead of prime focus, I decided to give eyepiece projection a try and managed to get a much larger image of Jupiter.

As before this image isn't one that will win awards but from what I can see from my initial tests, I may be able to get something decent with this setup providing the seeing improves. Again it was windy and Jupiter was relatively low in the sky - it's a school night after all!!

Also in the attached image is Callisto and Europa's shadow on the face of Jupiter. If anyone can find Europa itself I'd be very grateful...

And one last request - how does using a 10mm eyepiece affect my f ratio when used in an eyepiece projection imaging train?

Cheers,
Mario

[Saturn%5]

A very nice effort Mario, I wish my afocal work was that good as for your other question about f ratio im sure other with more experience can answer that.

cheers

Graeme.

[iceman]

Nice image Mario, nice and sharp!

[astronobob]

Amaizing how you get these results with an 8" newt, Top class !

[Shiraz]

Nice image Mario. Regards Ray

[Clayton]

Nice image Mario:thumbsup:
You can work out the f ratio by first working out the focal length with the following formula.
"The solution is to work backwards from a captured image and calculate the focal length directly. All you need to know the pixel size of your camera (in microns) and then use the following formula:

F = 206.265 x P x U
---------------
O

P is the size of the object in pixels as captured
U is the pixel size of the camera in microns
O is the true size of the object in arc-seconds
F will be the focal length as calculated from this formula, in mm"

Then simply divide by the aperture in mm (eg 200) to derive an f ratio. Jupiter was 49.4" (arc-seconds) Diameter on that night according to winJUPOS. You must of course use an image that has not been resized by resampling to retain the original number of camera pixels covered by the planet.
Hope that helps :)

[Clayton]

As to your other question Mario :question::question:
I have posted a crop of your image with a Black arrow where I would have guessed that Europa was at the time, and a Red arrow pointing to where winJUPOS says that it was. And a screen grab of winJUPOS so that you can verify the time and date (it seems very early?) and etc.:thumbsup::hi:

[cybereye]

Thanks everyone for your thoughts on my image.

I've gone back and stacked some other avi's that I took because there was a dark area just above Europa's shadow that I wasn't sure about. Rob, I too at first thought it was Europa's shadow but it now appears it is the darker area below it. It turns out that it was a stacking artifact that is not present in these newer stacks. However I'm not too concerned as it was only a test of eyepiece projection.

One thing I have determined is I really need to clean my eyepiece if I want to use this method for planetary imaging!!

Rob, thanks for your help on both counts. I've used the formula you provided and I've come up with a focal length of 6392mm and an f ratio of f/31. This sounds pretty big to me but the image was about twice the size of the prime focus image which was f/14. Therefore I'll stick with that value!!

Cheers,
Mario

[midnight]

Good capture there Mario!

I can't even get a consistent & noticeable banding at F8 the seeing has been horrible here. I was actually getting better with my 40D in video capture last year than my DBK this year!

Well done there.
Darrin...