Message posted by lone wolf on May 07, 2005 at 12:50:15 PST:

It is substantially much harder to make a panoramic if the camera isn't rotated cleanly, which is why I suggest using a bogen 410. I also level the tripod prior to shooting so that the seams in the image are at straight.

You will need a barlow if you shoot with a 35mm camera.

I got a Velbon carbon fiber tripod that goes in the back pack, so carrying it isn't an issue. A refractor certainly weighs more than a reflector, but the image quality is better due to the higher contrast of the refractor. Also, the focus of a refractor doesn't drift as the ambient temperture increases during the early morning photography from Tikaboo. I focus on the tower once using first a 6x magnifier then a 25x magnifier on the viewfinder screen and then don't touch the focus again for the rest of the shoot. Given the distance to the base, you are well within the hyperfocal range, and as I said, the refractor focus stays locked.

The link provided has some info on how to create panoramic images. You can correct much of the geometric distortion of a reflector using these tools. Both refractors and reflectors have a darkening towards the edge of the focal plane, though I see this more in reflectors. In any event, the tools in the link that fix this too.

Some other free software that is useful in long distance telephotography is:
http://rsb.info.nih.gov/ij/
http://www.astrosurf.org/buil/us/iris/iris.htm
http://registax.astronomy.net/

I've used the wavelet sharpening tools in imagej and iris. I find registax to be a bit unstable with very large images.

One program I haven't tried yet but am told is good is
http://pleiades-astrophoto.com/

Whatever type of camera you use, you need to make sure it can be set manually. For panoramic images, the exposure shouldn't change from frame to frame else the frames won't match. If you scan the 35mm film as I do, you need to make sure that the scanner isn't on "automatic" as well. The good thing about the lack of contrast when photographing over 26 miles is that the dynamic range of the camera won't be strained. It's been my experience that you should underexpose a bit since the haze tend to make the histogram shift to the bright side. Since I shoot film, I get around the low contrast condition by pushing the film one stop.

In Reply to: Re: Stellar View binos n' scopes posted by Chuck Clark on May 07, 2005 at 8:18:28 PST:

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