Posts Made By: David Simons

Hi Pete,

This one runs off 12V (the black box in the picture), but I think Radio Shack sold a 6V red lamp also. Then it could be powered by a lantern type 6V battery. I am sure there are a few folks that could modify a lamp like this with LED's to run off even a 9V battery. Orion sells a few red lights, but they are somewhat expensive.

I have also seen some hardware stores that sell various flashlights that come with a red filter.

Good Luck !

David Simons

Hi Alex,

The table lamp red light is much dimmer than the picture suggests, I'm using a Radio Shack 12V red panel indicator. It is actually anything but bright. It is just difficult to get the brightness levels in the picture to look right when they are very dim.

I have used this several times now in new moon mag 5.5+ skies, and found it to be about right. In fact The intensity can be roughly adjusted by varying the distance to the chart.

But of course you have a valid point, some folks go with an almost invisible amount of light. A simple fix would be to add a rheostat in series with the 12V. In fact a bought one of these in anticipation of this, but found the light level close enough to what I like, that I just used it straight.

Having a weighted base lamp that can hold down a chart is very convenient when the breeze starts up

David Simons

Hi Ron,

I played with the Beta version of this program, and it seems the first planet rendering I did came out a little rough. I then re-calculated it again, and it came out better. All subsequent renderings seem to be about right. It is just the first one that seemed too soft.

Which version are you using ?

Here is my attempt at rendering with different CO's. The bottom left is the raw image, then clockwise is a perfect 10" unobstructed simulation (dream APO?), note some of the fine detail is lost. Then a 10 inch with 12% CO. I cannot tell much difference here between 0% and 12%. Then the last shot is a 10" with 20% CO. Now the difference is subtle, but it is there. Some of the central banding soft detail seems to get washed out in the 20% CO case. My general impression is the high frequency detail is about the same, it is just the subtle soft details that get affected with the larger CO.

Although I would be proud to have a scope that gave images as good as the 20% central obstruction image : )

It would be interesting to run these images through image sharpening programs to re-introduce the details that are starting to fade out, and compare them to the original image.

David Simons

How about a C14 on a cheap pipe mount. I finally got the vibration down to about 5-6 seconds at 100X using the guy-wires.

I think the mount cost was a little over $100.

I can set this whole thing up in about 15 minutes, 5 if I leave the pipe mount together, as the C14 just sets down onto the rings. The base is round, so it acts like a big wheel when I move it around. My next modification is to make the setup easier and quicker to take apart, as the component pieces easily fit into my Camry.

David Simons

Hi Dave,

I have been going through a lot of your objects already with my very old C14 on it's new pipe mount. I have been using it as my quick setup scope now. The Sky-90 is starting to get jealous.

I am not usually a planetary nebula guy, but NGC6781 really was something in the C14. I suppose I could describe it as a big hockey puck. It lacked the beauty of M27, but had a similar impact.

David Simons

I believe this is a picture of the 90mm and 60mm fluorite scopes.

I think the 60mm would make an awesome finder.

David Simons

Hi Bart,

I shopped around for a dob conversion of my Meade 10" SN. I got numbers in the range of $400-500.

Yes they were works of art, but I wanted to try out the idea first to see if I like the scope that way.

Last May, I was at RTMC and saw a fellow with an old style pipe mount (he later won a merit award), and I was inspired. So I visited the hardware store, and spent $39, and in literally one hours time I had this mount. OK it looks it too but with a second iteration, + paint, and a rotating base with teflon etc., it should work very well. I am able to use the scope quite easily even with the small base.

The tools needed to build this mount, are a drill and screwdriver.

Sincerely,

David Simons


PS. The military aircraft spotting bino's and this wide field scope are a wonderful combination.

I'd use the $5 to drive to a dark sky site, bring a lawn chair, and enjoy !

Well, I might bring along a sky map and a pair of bino's.

David Simons

Hi Floyd,

I recommend a paper towel tube, and some Surplus Shed lenses

Specs:

Objective 38mm diameter X 200mm fl
Eyepiece 38mm X 50mm fl
Power 4X
FOV ???

Part List:

Paper Towel tube $0.00
Shipping tape ~$0.10
Objective $1.25
Eyepiece $1.50
Time ~ 15 minutes

Total Value: priceless

http://www.surplusshed.com/pages/category/educationaloptics_2.html

OK OK, yes it's cloudy over here

The eyepiece view is actully much sharper, I was hand holding the camera which caused a little motion during the exposure.

David Simons

PS, It actually has a pretty smooth focuser !

PSS, The tube looks a lot better if you have the kids draw stars and moons on it with felt tip markers

Hi Wes,

I have very much enjoyed all your lunar shots.

When does the "Wesley Higgins" CCD Lunar Atlas come out ? : )

I think it will a nice compliment to Rukls.

David Simons