Help needed! - Over exposure on Lunar images

[Droogie 2001]

Hi,

I have been Lunar, Planetary and DSO’s imaging for about 2 years now.

At this point I am just starting to feel more confident in the whole capture and post processing stages.

Leaving Planetary and DSO imaging aside I am specifically looking to find some tips and idea on how to control exposure and lighting on Lunar imaging as I cannot find much information either on the forums or the web.

Firstly a brief overview of my Lunar imaging kit:

Celestron 8SE (C8)
Celestron AVX Mount
Camera: ASI120MC (USB3)

Now my Imaging Software:

1. Firecapture v.2.4.05
2. PIPP v2.5.1 (just downloaded today!)
3. Registax v6
4. Photoshop CS2

Obviously I begin by using Firecapture to capture the specific area of interest. Switch the Firecapture ‘Capture’ software to Moon and adjust the exposure to something I feel is visually appealing. Also I adjust the Gain accordingly. I do not touch Gamma.

As to keep the thread brief I wont go through everything step. But I use ROI when required and I switch of De-Bayer. Then I process the AVI’s in the order detailed above.

My main issue appears to be in Photoshop and controlling exposure. Usually the craters edges are far too bright. I have tried many settings but ultimately I can do little to control the issue.

I regularly see lunar images with similar kit, though most appear to be on Mono camera, in particular a lot of AI120MM’s. Which are way above my level. Now I am not jealous (well I am a bit!  ) but I am at a loss why I am not getting any progress in this area. I realise there are people with larger scopes and perfect skies but again I am seeing people within the UK who are producing astounding images with similar kit.

I have come up with some possible reasons:

1. I am not capturing the AVI’s at the correct exposure level. i.e My Firecapture settings are wrong. If so how can I address this? I could lower the exposure but everything looks too dark. I have noticed a lot of my images are quite dark which is a result of not over exposing later on in post processing.
2. I am using the ASI120MC which is a colour camera and therefore have less sensitive captures. I have looked at an IR blocker but I believe I will need to remove a built in filter first. This is area I am a bit confused with but I know I cannot simply screw on a filter.
   I could trade it in and get a mono but I like the flexibility of colour, especially for planetary imaging. But if that is answer then I could go down the filter wheel route I guess…
3. I am using Registax and incorrectly stacking? I have tried denoising in Registax but it has not yielded the results I am looking for.
4. Issue is elsewhere!

I appreciate as mention above everyone has their ‘own’ preferences to capturing and there are numerous factors to consider. But if anyone can see a potential step I am missing or indeed making then it be much appreciated. I have tried many settings but to no avail.

I have included an attached image of an example (not my best  ) but it demonstrates the over exposed craters rims. My signature also contain my FlickR gallery which has some more examples too.

One point on Photoshop I have recently downloaded a trial plug-in copy of Topaz De-Noise and this has had a great effect of removing noise and leaving detail within the image. Basically I have gone through most of my images and cleaned them up. It of course does not address the exposure issue, I would however recommend this to anyone. You get 30 days free and it’s not cheap a $79 (about £50) but it can be used on all images including DSO’s & Planetary.

Anyway apologies for the long thread. Hopefully someone can give me some pointers?

Thanks

Moon_291214_Hyginus_Rille.tif

[Joseki]

Hi, I'd guess (1).  You say you "adjust the exposure to something I feel is visually appealing" but you should be adjusting your settings using the histogram ( http://firecapture.wonderplanets.de/help/options.html ) which will give a clear indication of how close you are to over exposing. - e.g. aim for the right hand end of the distribution curve to be about 75% of the way to max.  

[Droogie 2001]

Thanks for that. Will have a look at that next time. It does not seem to be possible to playback pre recorded AVI on Firecapture so will have to wait until I have another imaging session on the moon.

[knobby]

Definitely use the histogram ... Its very tough to guess when you're in a dark field looking at a laptop screen . also as with any photography, you can lighten up an underexposed image but once its overexposed the data is generally unrecoverable ... All the best of luck and keep at it