Mars from Melbourne this morning Jan 14

[John K]

Hi everyone,

Tried a new combo of my 5 x Powermate but also with a 2 x Barlow this morning and this will definitely pay dividends by the looks of things. The only down side is that there is less light to play with so the Red filter looks like it will deliver more light and more contrast than the IR685 pass filter.

RGB, Red and IR shots attached.

Mars is definitely growing!

Clear skies.

John K.

[iceman]

Looking good John! Good image scale.

[luvmybourbon]

really nice

[Astro_Bot]

So am I right in calculating that you used 12.5" at f/50 (or an effective focal length of just under 16 metres)?

Nice shots. :thumbsup:

[John K]

That's correct - looks like it's close to the limit for my scope at this image brightness level with the Skynix camera.





Thanks gents.

[Troy]

Good image
wow, plenty of power in your imaging train.

[Astro_Bot]

Thanks.

I'm trying to get my head around why your setup produced such good results. According to "the formula (http://www.iceinspace.com.au/forum/showthread.php?t=105057)" you're using about twice the f-stop/focal length recommended for a camera with 4.4um pixels (which the manufacturer's website tells me your Skynyx camera has). And you used a red filter!

Is the Skynyx a very sensitive camera and/or was seeing exceptional?

Edit: Sebbie's result at f/40 is pretty impressive also but I'm not sure what camera he's using.

[John K]

Some comments from me on this.

Actually the IR and Red channels are quite good on Mars, Green is the channel that gives me the most issues - if you think about it. Mars is mostly red and it actually has quite a high surface brightness.

When I step down the sensor to 240 x 240 pixels, I can crank it up to 29fps and have close to 90% of the histogram graph at the level where it needs to be.

The camera I have is the SKYnyx2-0 - it has 7.4µm pixels not 4.4µm - I find that the camera is quite sensitive, but in recent times more sensitive cameras with higher FPS have come on the market.

29fps is actually quite slow, but the beauty of Mars is that it rotates quite slowly. When it's only 8" in diameter, you can really take 15 min images and still achieve a 0.5 arc second resolution. For my photos I took 5 videos and could take and stack lots of frames as follows:

IR pass and Red only videos - 720 seconds each (12 minutes) - 20,000 frames shot - stacked 1,500

R,G,B videos - 200 seconds (3.3 minutes) - 5,800 frames shot - stacked 1,000 frames in each channel

As well, I am shooting in a SER mode which I think is like a RAW mode and 12 bit - so excellent data!

So overall, I think that even if the quality of the frames you collect is below optimal, if you can get enough of them with good seeing then the image quality of the end result will improve.

Lastly, the optics in my scope are excellent. Something like 1/18th wave made by OMI - so this does also helps! and I "chill" my mirror using active peltier cooling to get close to ambient which helps even more!!

[MarkJ]

Nice image John and thank you for sharing your techniques.

Mark

[Astro_Bot]

The larger pixels explain a lot. Also many thanks for sharing the rest - there's a couple of very useful pointers there. :thumbsup: