Image of the day

Captured by
Lawrence Parchman

Sculptor Galaxy (NGC 253)

About Astromart

My Account

New to Astromart?

Register an account...

Need Help?

Posts Made By: Alex McConahay

November 20, 2007 01:41 AM Forum: CCD Imaging and Processing/Deep Sky

how do I blind a ccd?

Posted By Alex McConahay
I don't understand what you are trying to do. What does "blind a ccd" mean? Are you trying to look for a color that cannot be seen by a ccd camera, or are you trying to develop a light ray of some kind that will damage a ccd? Or just what are you doing?????

If you are simply looking for a color that cannot be seen in a ccd camera, consider that each ccd chip has a characteristic range of sensitivity. The chip documentation usually has these sensitivity curves. Just find a color that is not within the wavelengths of the particular ccd chip you are trying to hide from. (By the way--it does not show as a color in the ccd chip, just a level of gray corresponding to the intensity of the color.) It will probably be difficult to do this with visible light because they are developed in general to allow one to see the visible spectrum.

Hope this helps.

Alex

November 22, 2007 12:17 AM Forum: Equipment Talk

Rebuilding a battery pack

Posted By Alex McConahay
Yeah, I've done it with my big old battery pack.

Just start disassembling it, and down underneath the case, you will find what loooks like a big, black battery. (Or two, or some variation). Take it out of the case.

Test it to see if it is really the reason things are failing. (I.E., try to charge it with something besides the battery pack system, and see if it holds a charge. If it does, then it is working, and the battery pack electronics may be at fault instead.)

Hit the web, or your local electronics store, for a replacement of the right voltage, size, amperage, storage capacity, fittings, etc. and buy it. Then just reassemble.

It is fun and educational.

Alex


November 22, 2007 10:44 PM Forum: Refractors

LXD-55 vs. CG-5 Mount for Meade AR-6 Refractor

Posted By Alex McConahay
I have and LXD55 I bought for my TV85/Pronto/and general outreach events.

Interesting to you is the way I bought it.

I had a friend who was disgusted by his 5 inch refractor (AR-5) on that mount. It was not steady. It would shake in the wind. He thought it was a disaster. I just wanted an inexpensive goto mount, and the LXD 55 fit the bill. SO I bought the whole thing, and immediately sold off the tube. With the TV85, the pronto, or an 80 mm F10 or so refractor I use it with, it does a fine job. (Visually--outreach--quick grab and go.....only. I don't do any more than occasional lunar shots with it.)

This tells me that it can perform well enough when not loaded, but that the 5 inch refractor just overloaded it. Hate to think of what a six inch would do to it.

As for a CG-5--Mine was very similar to the LXD55, so I would assume whatever is to be said for the one goes for the other--although I understand they have upgraded the CG-5 since I had mine.

Alex

November 25, 2007 04:22 AM Forum: CCD Imaging and Processing/Deep Sky

Dry ice coolant...?

Posted By Alex McConahay
I'll let more experienced jump in here--but that seems way past the point of diminishing returns for a cooled ccd camera. For a digital SLR, it might have some attraction if it could be properly engineered, but considering that much of the noise is generated inside the camera itself, you still might have (heat generating) electronics between the cold and the chip. Besides, isn't that below the operating temperature of these cameras?

Considering the potential for icing, condensation, and other problems--I wonder whether it would be of value.

Alex

Alex

November 26, 2007 03:59 PM Forum: Off Topic Discussions

MP3 Player / IPod / Zune Questions

Posted By Alex McConahay
Why not get a cell phone with an MP3 player in it, and eliminate one of the things you carry around?

Alex

November 28, 2007 01:22 PM Forum: Equipment Talk

mounts for piers

Posted By Alex McConahay
You are into the heavy duty range here. That is a lot for the Losmandy G-11.

Do you plan to do astrophotography?

Alex

December 10, 2007 03:16 PM Forum: CCD Imaging and Processing/Deep Sky

Monitors

Posted By Alex McConahay
Oh, lots of standards. That is one of the problems.

I use a piece of software/hardware from Spyder that calibrates my monitors. It is expensive, and does not work completely to my satisfaction (due, probably to my monitor's deficiencies). But it does make things nicer and more consistent from my laptop to my desktop.

To start with, if you have Photoshop, you can use a monitor adjustment program that comes with it.

And failing that, there are a number of places on the web that you can find a strip of sixteen blocks of gray. Adjust brightness/contrast so that you can see all the blocks distinctly, and you have come a long way. I'll go find one of them and post a link.

Alex

December 12, 2007 03:54 AM Forum: Equipment Talk

Using a SLR Lens as a Scope

Posted By Alex McConahay
I have such a device for my Olympus lenses. You should be able to get one for Nikon. It is just a bayonet mount on the front, with a 1.25 eyepiece holder on the back. I doubt you could get a diagonal to work with it. (not enough back focus).

If you want to make one yourself, you could use a back lens cap and a spare 2" to 1.25 adapter. See: http://home.roadrunner.com/~alexmcconahay/Equipment/Finder-Parfocuser/parfocuserindex.html
for how to do it. I use mine to focus for astroimaging, but it works fine as lens to telescope converter.

Alex




December 16, 2007 03:39 PM Forum: CCD Imaging and Processing/Solar System

White Spot on Saturn

Posted By Alex McConahay
Dude, why are you even thinking about that silly white spot.

Don't you see that other marking???!!!???

Surely the sign of an advanced bow and arrow using civilization on the planet.

Alex

December 19, 2007 03:14 AM Forum: Film Astrophotography - Imaging and Processing

Camera mounted on Guided scope...without the scope

Posted By Alex McConahay
Jim, of course it is possible to skip the scope.

To figure out just what you would need, though, we would have to know what type of mount you are talking about.

How does a scope currently attach to the mount? If it is a fork mount, it may be a little tricky. If it is a standard GEM, then you merely need some kind of plate that fits in the GEM saddle, and in turn has a 1/4-20 screw in it to hold the camera.

What kind of mount are you talking?
Of course, if you skip the scope, what are you going to use to guide the exposure? (Not that that is critical with most camera lenses.)
Alex

Funding Member

Sponsors


View all sponsors

Search