Close-up of Clavius with ASI120MM

EricB (Eric) · #1 07-03-2013, 08:57 PM

Hi there!

Here is a close-up shot of Clavius with the ASI120MM. It was imaged early in the morning just before dawn (a quick grab before going to work). The seeing was very average (as usual). The Moon was flickering rapidly during the capture and focus was very difficult to achieve.

Thank you for looking.

Eric

dannat (Daniel) · #2 07-03-2013, 11:07 PM

Good work Eric, good practice for better seeing

Dennis · #3 08-03-2013, 07:45 AM

Some nice details and resolution there Eric, despite the poor seeing.

Cheers

Dennis

EricB (Eric) · #4 08-03-2013, 06:22 PM

Thank you Daniel and Dennis for your encouragements.

Eric

EricB (Eric) · #5 10-03-2013, 05:45 PM

The same AVI reprocessed (10% of original stack selected) and reworked in GIMP (wavelet denoise + highpass sharpen filters) and sightly improved.

Eric

Larryp (Laurie) · #6 10-03-2013, 06:39 PM

I can see the difference, Eric. Looks a lot sharper-nice!

noeyedeer (Matt) · #7 10-03-2013, 08:07 PM

I wish I could do that ... but can't afford it

EricB (Eric) · #8 10-03-2013, 10:07 PM

Thanks Laurie and Matt.

Matt, I don't have a very fancy setup. A 10" dobs, an ASI120 camera and a 2.5x televue powermate.

noeyedeer (Matt) · #9 10-03-2013, 11:50 PM

would you recommend one of those asi120's. I've heard only good things about them. what I see here confirms that ... or are they a pain in the a$$?
or is it about the editing? the second pic is miles above the first one .... I like both but the detail in your last pic is lovely

h0ughy (David) · #10 10-03-2013, 11:58 PM

Quote:

Originally Posted by EricB

The same AVI reprocessed (10% of original stack selected) and reworked in GIMP (wavelet denoise + highpass sharpen filters) and sightly improved.

Eric

a little crispy in spots but overall very nice to look at!!!

EricB (Eric) · #11 11-03-2013, 02:29 PM

Thanks David!

Matt, you need a decent camera, decent data and good processing skills. If the seeing conditions are bad, you won't get exploitable data and there not much you can do about that. If seeing is average, you can pull out the kind of details I have extracted from my Clavius AVI (see the raw stacked image attached).

This photo has required quite a lot of processing. I have run the AVI several times through Avistack 2, selecting in turn 5%, 10%, 20%, 25%, 50%, 75% and 80% of the stack. I processed all the resulting stacked images in Astra image using the Lucy Richardson deconvolution tool and some very subtle wavelets. Then I compared the resulting processed images to select what seem to me to be the best one; it was the one based on 10% stack. Finally, I enhanced the photo in GIMP using the crop and levels function, as well as the de-noise wavelet and high-pass filters. I am sure that someone with better skills could get more details at of the data.

Capturing AVIs requires a bit of experience and skills, but it can be done fairly easily and quite quickly. It's early days for me using the ASI120MM. Due to the ordinary conditions I have experienced throughout summer, I haven't reached the full potential of the camera in relation to my gear. Given better seeing, I am sure the camera can perform better. There are very good examples of Moon shots taken with the ASI120 on Astrobin and on the ZWO optical website. Look at this one of Clavius, for example: http://www.astrobin.com/33598/B/ (ok, the camera was attached to a C14...)

The price of the camera is very attractive given that it rivals cameras that cost up to twice as much. I would recommend it (if your scope is equipped with a tracking function).

I hope this help.

Eric

noeyedeer (Matt) · #12 11-03-2013, 06:43 PM

Thanks for the detailed reply. Seems like less is more when the conditions are less than ideal. Does that mean if you were able to use the 50% stack, would you be able to process it more, or it just makes processing easier/harder?

looks like a good camera for it's price. I by no means will be doing any ap soon, I'm still saving to upgrade to a dob. its reassuring that you can still get some decent imaging with your setup.

Thanks for the advice Eric

Matt

EricB (Eric) · #13 11-03-2013, 07:17 PM

Mark, as I said in my first post the image was flickering and was very unstable, so I had al lot of bad frames in the mix. By going as far as selecting 10% of the original stack, I kept the best frames, however, the stack was small, which meant that I risked having a noisy resulting image. Still compared to the 75% stack image (which included more frames but bad ones too), the quality was marginally better. I must say it's the first time I go down so low.

Good luck with the purchase of your dobs. Mine has been great. I reckon a 8" or a 10" is a good starting point, then you will be taking great pictures of the Moon in no time!

Eric

peter_4059 (Peter) · #14 11-03-2013, 07:33 PM

How does the ZWO compare to your DMK?

noeyedeer (Matt) · #15 11-03-2013, 08:21 PM

Thanks Eric. Sounds like there is a fine line in determining which stack to begin with. I'm on a phone so the resulting noise isn't so obvious (in anyone's image really), but I can see the huge difference from start to end.

Havnt seen much of the sun this summer, let alone the moon

thanks again

matt

EricB (Eric) · #16 11-03-2013, 08:50 PM

Quote:

Originally Posted by peter_4059

How does the ZWO compare to your DMK?

Peter, by chance I also imaged Clavius with the DMK41 during the imaging session. I have just processed the DMK in the same way I did the ASI one. I have attached both for comparison.

For me, on this particular subject, the ASI120 has a slight edge. The photo displays a little bit more details than the DMk's. One thing I find, is that ASI photos tend to be soft-textured compared to the DMK's. It quite obvious here. To you might prefer the DMK's because if the harder tones.

One thing though is that the DMK has consistently performed slightly better than the ASI120 on the Moon (but not on Jupiter). However, one must take into account that I get a higher magnification with the ASI because of the chip, so everything else being equal, sharpness is more difficult to attain with the ASI because of that.

I let you be the judge of which photo is better. First is the ASI120, second is the DMK41.

I will keep operate both cameras to compare them.

Mark, here in Adelaide, we pray for rain and cool weather...

Cheers,

Eric

peter_4059 (Peter) · #17 11-03-2013, 08:58 PM

They look very similar apart from the image scale.

EricB (Eric) · #18 12-03-2013, 07:14 AM

They are very close indeed.

Eric