Quick question from a mostly visual observor

[TheThing]

Most of my astronomy is on the visual side as I don't have the time, money or patience to dabble in the dark arts.

Occasionally though, I have been known the hold my little digital up to the eyepiece and snap a few shot of the moon when the mood takes me. It's just a simple 4.6mp Nikkon Coolpix.

I realise that this isn't astrophotography in the real sense, but it makes me happy!

I know little about photography, so can you tell it to me like I'm a 6 year old please?

Just a few quick questions then, for those with the real skill and knowledge: -

• 
  [li]I normally leave the moon filter in place when I take the photos. This leads to a slight 'green tinge' to my shots. Is this an accepted norm or should I be taking the filter out? If the later, should I then be shortening the length of the exposure to compensate? (Basic camera only goes from +3 to -3 on the exposure front)[/li]
  [li]Is there any processing software that should be used to tweak the resulting photos? I normally just bung the on the computer and view them thru Windows picture manager, but should I play around with them first? If so, can you suggest some (hopefully) free and (even better) on-line software so I can play on the work PC without having to download?[/li]
  [li]I tend to get really bad vingetting when using Tal EPs (40mm and 25mm) with the 2x Barlow. Other EPs (like a Meade 15mm Super Plossl and a 18mm Ortho) don't suffer so much from this thru the same Barlow. Could it just be a combination of the EPs and Barlow?[/li]
  

Sorry for all the questions and thanks in advance for your help!

[Doc]

• 
  I normally leave the moon filter in place when I take the photos. This leads to a slight 'green tinge' to my shots. Is this an accepted norm or should I be taking the filter out? If the later, should I then be shortening the length of the exposure to compensate? (Basic camera only goes from +3 to -3 on the exposure front)[/l][/l][/l][/l]

I would leave the moon filter out and just play with different settings. Not knowing this camera is a bit hard to advice but generally as the moon is very bright you might have to lessen the exposure.

Is there any processing software that should be used to tweak the resulting photos? I normally just bung the on the computer and view them thru Windows picture manager, but should I play around with them first? If so, can you suggest some (hopefully) free and (even better) on-line software so I can play on the work PC without having to download?

I always process my photo's not much but just basic curves and a bit of sharpeninng. For a free program use GIMP.
Just put gimp into google it's free and very good.

• 
  [li]I tend to get really bad vingetting when using Tal EPs (40mm and 25mm) with the 2x Barlow. Other EPs (like a Meade 15mm Super Plossl and a 18mm Ortho) don't suffer so much from this thru the same Barlow. Could it just be a combination of the EPs and Barlow?[/li]
  

Placing a camera up to the eyepiece will always give you vignetting. Two options process the vignnetting out with cropping or buy adapters to fit camera to eyepiece.

Hope this helps.

[TheThing]

Thanks Mick, that's all very useful info.

[Talitha]

Which Nikon CP do you have? I've been using a 4300 on Luna since 2004 with pretty good results.

[TheThing]

Carol,

I have the 4600. How do you get on with yours?

[Talitha]

The pics turn out pretty good (see photo link in my signature) as long as the seeing's decent. They're just single image studyshots though, mostly taken through the 8" SCT. Here are a few pics of the Scopetronix adapter used to secure the camera to the eyepiece, and the 10mm ep which is used for most of my lunar images.

The adapter originally came in three pieces which needed to be taken apart in order to change ep's and I assume the manufacturer did it this way in order to be able to use universal components for different cameras. But it was a pain messing with small Allen wrenches and tiny set screws, so the set-screws were replaced by machine screws when I glued the three pieces together into one solid unit.

No filter is used when imaging with the 8" SCT, but I have used the William Optics VR-1 CA filter with the refractors and it improved the image but the color bothered me so I just brought it down to 'zero' when tweaking and it looked ok.

The camera is set on manual at the fastest speed available, 400 ISO. The only thing I find unacceptable regarding the 'manual' setting is that the camera decides what aperture to use. I can define larger or smaller, but have no control regarding the actual setting and it often limits what I can capture on dark areas like the maria. I can get a brighter image by choosing a longer exposure time, but then the seeing comes into play and they can get pretty soft. Yes, I could probably stack a bunch but TBH I couldn't be bothered. Being an observer and not an imager, my interest lies in the content of the image.. not the appearance of it.

The 4300 has an external zoom which moves out into the adapter when the camera is turned on. I always use 3x zoom.. it's the limit of the 'optical' zoom and anything beyond that (10x capability) is digitalized and not as sharp. Photo program used is Picture Window Pro.

Hope this helped.