Posts Made By: Doug Scobel

OK, enough of this name/initial baloney and let's talk eyepieces.

I'm looking for a wide field eyepiece in the 28-32mm focal length range that will work well in my f/4.5 scopes (13.1", 6"). I have a ParaCorr to correct the coma, but still the EP must be well corrected at the effective f/5.18 focal ratio. I want as good of correction to the edge of the field as I can get.

By wide field I mean 60 degrees AFOV and up. I don't want to go longer than 32mm because my getting older by the minute eyes can't handle the exit pupil (I'd like to keep it to around 6mm and under), and under 28mm I'm getting a little close to the 24mm Panoptic I already own.

Yes, I know about the 31mm Nagler, which I'm sure would be perfect, but it's a little hefty both weight and price-wise. Any other recommendations, preferably EPs you have direct experience with?

Thanks,
Doug

I'm looking for anyone who has direct experience using a Pentax 30XW in a fast scope, f/5 or faster. Most everything I've found so far is with slower FR's. I'm particularly interested in edge of field performance.

I would be using it in f/4.5 scopes with a ParaCorr.

Thanks,
Doug

Here’s an image of the nearly first quarter moon I took last Thursday night (June 21, 2007). It’s a mosaic of five separate images taken through my homemade eight-inch f/8 Newtonian reflector. I used a Nikon Coolpix 800 point-and-shoot digital camera mated to a 14mm Tele Vue Radian eyepiece. I let the camera auto-focus and auto-expose. I used Panorama Maker version 3.1 to create the mosaic and Paint Shop Pro version 8.0 for the digital processing. North is at the top.

If you want to see the full-res version, go here http://www.umich.edu/~lowbrows/astrophotos/moon/moon15.html and click on the image.

Enjoy!

Doug

http://www.umich.edu/~lowbrows/reflections/2007/dscobel.26.html

I've since replaced the old helical focuser with a Moonlite CR-2.

Doug

Here's a composite of eighteen images, starting at 4:47 and ending at 5:58. I used my Canon PowerShot A620 with 1.75x teleconverter, mounted on a tripod. Exposures ranged from 1/640 second to two seconds, all at an effective f/7.2. I used Paint Shop Pro version 8.0 to assemble the composite.

Hope you all got to see the show, it sure was purdy!

Doug

It's essentially a month away - who's in?

Doug

Here's a photo I took a few days ago. Olympus OM-1, Zuiko 200mm f/4 lens. Kodak E200, 20 minute wide open. Push one stop during processing.

This is the raw scan (shrunk down to 800 x 640 pixels for display here). My next post will contain my best processed image, and a question.

Doug

http://picasaweb.google.com/djscobel/OTSP_Sky_Shots

Comments/criticism/suggessions welcome.

Doug

I've been working on the Herschel II list for a couple years now and the only one that has eluded me so far (I have 49 to go) is NGC 1990. It is supposed to be a large, faint, reflection nebula surrounding epsilon Orionis, the middle star in Orion's belt, AKA Alnilam. I've tried many times to observe it, and never have I convinced myself that I'm seeing anything other than the scattered light I see around any other comparably bright star, such as delta to the WNW. I even tried with no luck from the Okie-Tex star party last fall. I've used everything from an 80mm refractor to a 13.1" reflector, all to no avail.

And if you search on the Internet, there are many respectable observers who doubt its existence. There is really only one image of it that I've found, but a single hit amongst a lot of misses doesn't constitute proof to me.

Perhaps it does exist, but there is precious little evidence for it. If it really is there, IMO it must be of such low surface brightness that it is virtually impossible to observe visually. Or maybe not?

So my question is, have any of you actually observed it? And I don't mean do you think you saw it, but that you definitely, positively saw something there.

Thanks,
Doug

Hi, all, I finally got a chance to use my new ImagingSource DMK video camera (I picked it up last month) on the moon Friday night. I'm quite happy with the results considering it was my first try at using the camera and Registax.

I used my homemade 6-inch f/4.5 Newt "Smurfette" with a 2x Barlow. Started with about 500 frames (.bmp) each, don't know exactly how many ended up in the final images tho. The images are just under four arc minutes on a side, with north towards the upper right.

Doug