Photographing the Moon

[porsche]

Hi, I want to get into astrophotography sometime. I was wondering what sort of exposure lenghts are we talking about for good lunar images?

[phreedle]

Originally Posted by porsche

... what sort of exposure lenghts are we talking about for good lunar images?

The moon is a very bright object, so you will need surprisingly short exposure times. This picture only needed 1/500:



When I made the photos for a time lapse video of a lunar eclipse (posted in the moon forum, check it out if you're interested), I used exposure lengths betweenn 1/60 to 1/250 at f5.6 and 800 ASA.

For detailed pictures of craters and the like, you could also use a webcam in the place of a telescope eyepiece. You record a webcam video and use special software (like Giotto or Registax) to process your data. Here's an example for that (a bit overexposed at the top, I'm still learning :-)



Hope that helps, phreedle

[porsche]

thanks nice pics! yes that will help me with exposure times. What about moon filters do you use recommend any for photos or does the exposure time take care of most of the light issues?

[phreedle]

Originally Posted by porsche

What about moon filters do you use recommend any for photos or does the exposure time take care of most of the light issues?

Moon filters are usually neutral-grey filters for visual observation. If you look at the full moon with a telescope, it's so bright for your night-adapted vision that it actually hurts! Plus, when you take your eyes away from the eyepiece, it feels like you have an eyepatch over the "telescope eye" because your night vision is gone.

With a camera, there's really no need for a filter. Like you said, exposure time is the answer.

[admin]

thanks for the tips Phreedle did you mod your webcam? would love to know how you did this and how much it cost.

cheers

[phreedle]

It's not much of a modification. I use a standard Philipps SPC900nc webcam which sells for about 65 Euros in my part of the world.

I removed the original lens and replaced it with an 1.25" eyepiece adaptor (29 Euros) which screws onto the cam. I also have an IR blocking filter (35 Euros) attached - apparently IR light makes the image blurry.


Individual parts: Cam, original lens, 1.25" eyepiece adaptor, IR filter


Ready to go!

There are other modifications around like replacing the original chip for deep sky imaging, but since I'm not into high-precision soldering, I haven't tried any of those.

For moon and planets, you can do quite a lot with this setup.

clear skies, phreedle