My first Mars image for 2005

[anthony2302749]

Hi all

Tested the Lumenera out on Mars last night. As this is the fifth time I have used the camera and the first attempted at imaging Mars, the image is not perfect. I still need to work out the bugs. Checkout the image and let me know what you thing.
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http://www.asv.org.au/index.php?opti...=1&key=5&hit=1

Anthony<o:p></o:p>
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Lumenera LU075Colour,
10” Meade LX200 Classic <o:p></o:p>
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Eyepiece projection<o:p></o:p>

Telescope Focal Length – 2500mm
Telescope Focal Ratio - f10
Eyepiece Focal Length – 10mm
Distance from Eyepiece to CCD- 60mm
New Focal Length: 12500
New Focal Ratio: 50<o:p></o:p>

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5000 @15fps, Stacked and processed the best 250 from 5000 frames with Registax 3 & Photoshop<o:p></o:p>

[beren]

Nice work Anthony , 5000 frames hey! now thats dedication

[iceman (Mike)]

Nice image anthony, what was the seeing like? It looks like the image is affected by the huge focal length, and the seeing not being able to support that magnification.

Stuart, with those LU cameras they can support over 60 fps without compressing the data, so 5000 frames doesn't have to take a long time like it does with the ToUcam where you try and capture at 5 or no more than 10fps to limit the data loss through compresison.

[anthony2302749]

Hi Mike
I would say the seeing was around about 5 and you maybe right about the focal lenght being to large, these are just small bug which I will fix in due course. As for the high frame rate for the LU cameras, from what I have read and learnt about the camera so far is larger the aperture higher the frame rate one can go.

I have a 10" SCT and have tried 30fps, but to get a visiable image on the screen you must increase the gain which then introduce noise. 15fps works very well with my setup.

Anthony

[Robby]

Nice image Anthony!!
I remember at the last mars flyby we ToUCams had just been invented & Gary & I were tearing our hair out trying to get the a half decent image! If we started out like you have I'm sure we'd be less grey now!
In terms of focal length the seeing certainly does have a factor, but generally we were imaging at around 5,000 to 10,000mm f/l. Gotta get the image scale up as best as possible. I remember one night stacking a 5x and a 2.5x powermate together in gary's MN. Gave us a focal length of 15m! If I remeber righty we only did it once!
Cheers

[anthony2302749]

Hi Robby

If I'm right, the required focal lenght depends on the size of the pixels in CCD camera. For the good old ToUCam that is about 4600mm. This will give an image scale of about 0.25 arcseconds/pixel which is what Starizona CCD Guide (http://www.starizona.com/ccd/advimagingplanet.htm) recommended.

For the Lumenera the focul lenght is about 6100mm = image scale of 0.25 arcseconds/pixel. From what I have read so far, users of the Lumenera cameras have been using focul lenght of around f30 to f50 which will give an image scale of 0.05 to 0.03 arcseconds/pixel. It is O.K. to have a image scale less then 0.25 the limiting factor is the weather. You can not obtain high resolution images if the seeing is poor. Also the scope setup will also need to be checked out e.g collimation.

Anthony

Originally Posted by Robby

Nice image Anthony!!
I remember at the last mars flyby we ToUCams had just been invented & Gary & I were tearing our hair out trying to get the a half decent image! If we started out like you have I'm sure we'd be less grey now!
In terms of focal length the seeing certainly does have a factor, but generally we were imaging at around 5,000 to 10,000mm f/l. Gotta get the image scale up as best as possible. I remember one night stacking a 5x and a 2.5x powermate together in gary's MN. Gave us a focal length of 15m! If I remeber righty we only did it once!
Cheers

[Robby]

Yeah thanks Anthony...
I don't go into the maths of it much, & I ashamed to say that I didn't really understand you post (sorry )... Trial and error seems to be the best method for me, and as you say, you can only go so far if the seeing is crap! The more you do it the better you get. For me image size was key. There was very little I could do with an image at short f/l when the number of pixels the planet fitted in was about 10x10
Here's an image I took exaclty 2years ago during the last close approach of Mars. The focal length was 4.88m (or f25 in my old C8).
I'm looking forward to having another go with the new C9.25 when the planet is a bit more socialable.
Cheers

[ving (David)]

nice one anthony!