Keyhole with Tal 200k

avandonk · #1 12-01-2006, 02:13 AM

Here is a stack of 8X120sec at 2000mm F10 Tal200k, no filters, Moon 90% taken with 5DH @ ISO 1600. Autoguiding has a slight problem with a focal length of 2000mm but I chose the best of the worst. Just a test.

http://users.bigpond.net.au/avandonk/Car_Tal.jpg

Bert

davidpretorius · #2 12-01-2006, 07:18 AM

I tell you what, i know that watching detail appear on a planet whilst imaginig is exhilarating, but watching stuff appear that the eye has no hope of seeing, must be even better.

another great effort bert

Robert_T · #3 12-01-2006, 07:25 AM

very nice Bert

what are you using as an autoguider? maybe one of the commercial SCT focal reducers would work on your TAL to get down to F6.3 or 3.3 - more light and perhaps more within the tolerance of your autoguider?

cheers,

Itchy · #4 12-01-2006, 07:38 AM

Hi Bert,

Not Bad for "just a test"

And with a full moon too!.

I bet you can't wait to get that camera under a dark sky.

I grabbed your Jpeg and reprocessed it. Focus was not as tight as it could be, but I say that without knowing the limits of your optics at 2000mm fl. There is what appears to be a dust mote in the upper centre (I cloned that out). There was no vignetting as in your other shots. I also notice that image size was reduced. Did you crop or just resize?

I must say that although I only used your jpeg, I am still very impressed with the data that your 5DH is producing. Under a dark sky in winter, it should be sensational!.

Cheers

avandonk · #5 12-01-2006, 08:41 AM

Yes it was a crop, here is a full frame pic. The Tal only has a 27mm aperture in the supplied T-mount. The focuser is primitive (only 1 1/4") and almost impossible to get good focus. The guide scope only has 340mm focal length. I have made a focal reducer for the Tal. I don’t usually use it for imaging because of the focuser.

I just wanted to get an idea how the camera would perform at 2000mm @ F10. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com[img] /><o:p></o:p></o:p>

The dust mote appeared soon after starting imaging as the sensor is exposed to the atmosphere (no filter) when on the Tal. I will clean it this morning.<o:p> When the Moon is out it is time to test. </o:p>

<o:p>Under a dark sky and a decent Newtonian or SCT or RC the results with this camera should be quite good.</o:p>
<o:p></o:p>
<o:p>Bert</o:p>
<o:p></o:p>

h0ughy (David) · #6 12-01-2006, 08:51 AM

looks like the 5D is the new benchmark, I wonder if they will do a 5Da. Top shot!

Itchy · #7 12-01-2006, 10:05 AM

Quote:

Originally Posted by avandonk

Yes it was a crop, here is a full frame pic. The Tal only has a 27mm aperture in the supplied T-mount. The focuser is primitive (only 1 1/4") and almost impossible to get good focus.

LOL. I can see why you cropped it.

Even with these bad conditions, it is a great image.

Cheers

atalas · #8 12-01-2006, 12:39 PM

Nice shot Bert

Striker (Tony) · #9 12-01-2006, 12:53 PM

That chip is huge Bert...we would have to be getting to the maximum chip size with this camera...any bigger and it's hardly worth it as you cant use it anyway.

Nice stuff bert.