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Ok I admit it Im failing to Fall in love with Luna

Psychobilly

By Psychobilly
in Imaging - Discussion

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Psychobilly

Psychobilly

Posted
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Rubbish technique is making it difficult in my Quest to Love Luna...

I have various tools at my disposal including an LPI and SPC900 as well as a range of DSLR's , filters etc...

Scope wise I have the Megrez 72, CPC800 and ETX 105.... where should this lunar numptee start?

Any pointers to using webcams for lunar imaging and processing with Registrax greatley appreciated...

Cor that was much easier than saying i'm an alc.... got to face up to your fears...

Just a Small VnC to calm the nerves honest...

Billy...

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jgs001

jgs001

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Go with what Gaz said. If you work out how to do this stuff... any hints greatfully received :) . I still don't have the settings and things ironed out. I did find QCFocus and WCCtrl worked really well as a combo for capturing. WCCtrl also allows up to 8 different sets of webcam settings to be stored.

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Psychobilly

Psychobilly

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Thanks Gaz,

I have a Baader Neodymium and the plain Baader UV/IR cut... and Celestron colored filter set.

Ant has already pointed out that I had the frame rate way to high...

The CPC need tighter collimation if I am going to use it for imaging as its normally just used as a guidescope.. and seeing as it has the 3d counter weights and the Megrez hung of it has a hard life...

Ant reckons the Megrez 72 with the SPC would be a good place to start...

Billy...

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Psychobilly

Psychobilly

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Frames from the DSLR wouldnt really be an issue I could soon take several hundred its just teh satckign that would be a problem found registrax doesnt like them could resisze them all but hat would defeat the object of imagign with an 8MP sensor...... the webcam is going to be my fiorst port of call and im interested in Pauls suggestion... forgot that I had got some IR filters for use with the modded 350D... and machined an adaptor to use them on the Megrez72...

So i guess that imaging in the IR will help with the seeing?

Billy...

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GazOC

GazOC

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So i guess that imaging in the IR will help with the seeing?

The IR will help a lot with the seeing but the problem with using them with colour webcams is the that camera already has a filter over the mono chip to give the colour, if you put another filter on top of that (esp. a narrow band one) too much of light is lost before it gets to the chip at the higher focal ratios used for lunar imaging.

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RichieJarvis

RichieJarvis

Posted
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*shakes head in disgust*

Another DSO imager turning to the darkside :nono:

Seriously though - after seeing what the SXV-H9 can do on the moon unfiltered, I might have to give it a go with a red filter.... Theres a guy whose written a live video module for the H9 as well, so I'll have to give it a try....

Anyway - I've just been told to pack up and watch Kung-Fu Panda with the kids :)

Cheers,

Richie

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Psychobilly

Psychobilly

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So thats in addition to the UV/IR cut thats normally lost when the "filtered" lens is removed from the webcam?

Might try soem terestrial experiments tomorrow...

Thanks peeps lots of things to try next time I get to see luna... hope she doesn't mind...

RJ this Beggar can't be a chooser... so needs to image whatevers in the gaps...

Billy...

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michaelmorris

michaelmorris

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Billy

For what it's worth here is my advice on lunar imaging.

1) Get hold of a copy of 'Lunar and Planetary Webcam Users Guide' by Martin Mobberley - it's a gem.

2) Use an IR Pass filter on the front of a Phillips webcam.

3) If you've got the colour Phillips webcam, apply the optimised non-RAW modification or the RAW modification to the cameras firmware. This can be found at: http://www.astrosurf.com/astrobond/ebrawe.htm#AviRAW

4) Using an electric focusser spend as long as iot takes to get the best possible focus.

5) Make sure that highlights are not burned out. The Luminance meter in K3CCDTools software is useful here. I try to set gain levels so that the metre never exceeds 230.

6) Capture between 1000 and 2000 frames at 10fps (never higher). (5 fps if the seeing is truly exceptional)

7) Use the 'two pass' method of alignment in Registax: This is it:

a) Load your AVI into Registax and do a single point alignment on a relatively high contrast feature near the centre of the frame. Pick a largish alignment box.

:) For a reference frame use the 'create reference' button in the optimise window. Sharpen it only using level 1 and 2 wavelets.

c) When this is complete optimise then, in the Stack window go to the Save registered AVI tab and select save registered AVI maximum area and rename the AVI (i just add 'reg' to the end of the file name) Be aware of some issues here.

- The resulting AVI file will be twice the size of the original

- If you click on anything else in any program (inc Registax) during the save process you will probably end up with a blank AVI (bug)

d) Close down registax then reopen it and load the new registered AVI (intermittent bug)

e) Run multipoint alignment on this registered AVI.

- You will now not have alignment points wandering off the edge of the frame

- You can now pick quite low contrast alignment points with far less risk of the alignment box wandering.

8) The best processing techniques I have found involve using the 'Focusmagic' Photoshop plug-in for sharpening.

http://www.focusmagic.com/

Bob Pilz and Tony Gondola have produced some great summaries of this technique.

http://www.digital-flight.com/thebigeye/essays.htm

http://digidownload.libero.it/glrgroup/selenologytoday9.pdf

If you do end up with a few small areas of burned out highlights you could try resetting the white point in Levels to 248 instead of the default of 255. The very judicious use of the 'dodge' tool in Photoshop can also help with taking the harsh edge off slightly overexposed highlights.

If you then want to up the resolution and reduce noise can I recommend getting a mono-chipped Toucam from Astronomiser (<£100) or a DMK 21 camera (>£250). They both have the same mono chip. The DMK has a faster frame rate (upto 60 fps)

I hope this helps

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dark knight

dark knight

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I've been using the Celestron Neximage for all my lunar stuff and found it works great especially if you flash the onboard eprom. I used Wcrmac to carry out the software mod which allows you to extend the shutter speeds and frame rates. It also allows you to use RAW, and if thats not enough to play with you can create macros,,and its freely available. I think it can also software mod other makes of web cam. There is a specific Wcrmac forum for any help, but I found the upgrade a doddle. I'm no expert but feel I have had some satisfactory results. I'll post some images if wanted. heres a link to the site which explains the process, functions and download,,http://www.burri-web.org/bm98/soft/wcrmac/hope it helps someone.

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  • 2 weeks later...
Dangerous-Dave

Dangerous-Dave

Posted
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Billy

For what it's worth here is my advice on lunar imaging.

1) Get hold of a copy of 'Lunar and Planetary Webcam Users Guide' by Martin Mobberley - it's a gem.

2) Use an IR Pass filter on the front of a Phillips webcam.

3) If you've got the colour Phillips webcam, apply the optimised non-RAW modification or the RAW modification to the cameras firmware. This can be found at: http://www.astrosurf.com/astrobond/ebrawe.htm#AviRAW

4) Using an electric focusser spend as long as iot takes to get the best possible focus.

5) Make sure that highlights are not burned out. The Luminance meter in K3CCDTools software is useful here. I try to set gain levels so that the metre never exceeds 230.

6) Capture between 1000 and 2000 frames at 10fps (never higher). (5 fps if the seeing is truly exceptional)

7) Use the 'two pass' method of alignment in Registax: This is it:

a) Load your AVI into Registax and do a single point alignment on a relatively high contrast feature near the centre of the frame. Pick a largish alignment box.

:( For a reference frame use the 'create reference' button in the optimise window. Sharpen it only using level 1 and 2 wavelets.

c) When this is complete optimise then, in the Stack window go to the Save registered AVI tab and select save registered AVI maximum area and rename the AVI (i just add 'reg' to the end of the file name) Be aware of some issues here.

- The resulting AVI file will be twice the size of the original

- If you click on anything else in any program (inc Registax) during the save process you will probably end up with a blank AVI (bug)

d) Close down registax then reopen it and load the new registered AVI (intermittent bug)

e) Run multipoint alignment on this registered AVI.

- You will now not have alignment points wandering off the edge of the frame

- You can now pick quite low contrast alignment points with far less risk of the alignment box wandering.

8) The best processing techniques I have found involve using the 'Focusmagic' Photoshop plug-in for sharpening.

http://www.focusmagic.com/

Bob Pilz and Tony Gondola have produced some great summaries of this technique.

http://www.digital-flight.com/thebigeye/essays.htm

http://digidownload.libero.it/glrgroup/selenologytoday9.pdf

If you do end up with a few small areas of burned out highlights you could try resetting the white point in Levels to 248 instead of the default of 255. The very judicious use of the 'dodge' tool in Photoshop can also help with taking the harsh edge off slightly overexposed highlights.

If you then want to up the resolution and reduce noise can I recommend getting a mono-chipped Toucam from Astronomiser (<£100) or a DMK 21 camera (>£250). They both have the same mono chip. The DMK has a faster frame rate (upto 60 fps)

I hope this helps

This is excellent stuff Michael.

However, Re: #6 - why do you suggest only using 5fps if the seeing is exceptional? Surely 5fps uses less compression than 10fps, the exposure length is determined by the exposure slider and, as the moon is not rotating, we don't have to worry about grabbing as many good frames we can in a narrow rotation slot? These days I use a DMK21AU04.AS which can do 30fps uncompressed, but when I used a mono-chipped Toucam I found the best results were at 5fps. With the RAW modification are you able to bypass the software compression at 10+ fps?

Regarding filters, as has been mentioned earlier an IR-pass tends to pass light of longer wavelengths which are least disturbed by atmospheric movement. However the overall light transmission is reduced radically, so you might find it harder to use at higher magnifications and/or with a smaller telescopes. You might find yourself inching the gain slider ever upwards which adds noise.

A red broadband filter does a similar job, though not as well, but passes more photons. I find a green filter useful to boost contrast at low focal lengths and on nights of good seeing (albeit I don't seem to get too many of those!!)

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michaelmorris

michaelmorris

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... why do you suggest only using 5fps if the seeing is exceptional? Surely 5fps uses less compression than 10fps, the exposure length is determined by the exposure slider and, as the moon is not rotating, we don't have to worry about grabbing as many good frames we can in a narrow rotation slot? .... when I used a mono-chipped Toucam I found the best results were at 5fps.

I have usually found 5fps a bit to slow to prevent slight blurring caused by poor seeing. Saying that, I've never tried it on my mono Toucam, although I can't see how it would make any difference what webcam I use - it's the speed (5fps) that is the issue. Perhaps you are blessed with generally better seeing than I get in my suburban back garden?

Regarding filters, as has been mentioned earlier, an IR-pass tends to pass light of longer wavelengths which are least disturbed by atmospheric movement. However the overall light transmission is reduced radically, so you might find it harder to use at higher magnifications and/or with a smaller telescopes. You might find yourself inching the gain slider ever upwards which adds noise.

A red broadband filter does a similar job, though not as well, but passes more photons. I find a green filter useful to boost contrast at low focal lengths and on nights of good seeing (albeit I don't seem to get too many of those!!)

Yes, I agree the literature supports the view that, in times of good seeing an imaging green filter (Green + IR cut) is the best option. I very rarely get seeing that good. On the matter of gain - with lunar imaging I find that I rarely have to go down to less than 50th sec exposure setting if shooting at prime focus through the IR pass filter; so high gain settings just aren't an issue.

If I'm using a 2x barlow I usually shooting at 25th sec exposure setting and gain of between 10 and 40. With 2000 frame captures I only rarely get a problem with low signal to noise ratios. However, after your comments, I may well invest in a red filter to use for shots where the gain setting has to be set high because the area is in dense shadow, this should improve the S/N ratio.

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