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Posts Made By: Mike Gibson

July 20, 2003 05:06 PM Forum: Solar System Observing

Mars observation (July 20, 2003)

Posted By Mike Gibson
Ron - Solis Lacus is tough for my FS102 as well, but I have bagged it visually this year. I can see it only at high power when conditions permit using a #21 Orange (48mm) and jacked up binoviewer (Baader/Barlow/Pentax orthos).

Here is a simulation of varying power from images taken Saturday morning. Any degradation in conditions will make it harder to see Solis Lacus, despite its contrast.

Keep trying with the TV102...4" apos rule! smile


July 20, 2003 10:12 PM Forum: Equipment Talk

Opinions needed on Collimation!!

Posted By Mike Gibson
True, there are some primary cell location and secondary holder configurations that would be OK with a skewed focuser, but usually we want the Newt components orthogonal with the focuser as reference datum and the primary aligned with the tube axis.

To square the focuser, just measure the tube's circumference and use a sight tube or laser to see a mark or hole on the opposite side with equal semi-circle lengths. Don't use wobbly 1.25" adapters. Adjust or shim the focuser as necessary.



July 21, 2003 12:54 AM Forum: Equipment Talk

Baffling isn't it?

Posted By Mike Gibson
Try Dale Keller's Newt program:

http://home.att.net/~dale.keller/atm/newtonians/newtsoft/newtsoft.htm

July 21, 2003 02:23 AM Forum: Equipment Talk

Image stacking/processing

Posted By Mike Gibson
There are lots of ways to skin this cat. Capture your raw webcam video at the slowest frame rate/ highest resolution possible (5 - 10 FPS). Registax will step you through frame selection, alignment, and stacking process, but you may wish to play with default settings for best results. Photoshop can touch things up and apply unsharp masking as desired.

For Mars, an infrared blocking filter is recommended because the ToUCam's Sony HAD chip will bloom a bit. Color filters can be used to highlight specific features.

See this group for everything webcam:

http://groups.yahoo.com/group/QCUIAG/

July 21, 2003 01:31 PM Forum: Equipment Talk

Marine battery=Deep Cycle ?

Posted By Mike Gibson
It depends. Many marine or 'deep cycle' batteries sold today are actually hybrids that should not be discharged greater than 50% because they have thinner, spongy plates, not the solid plates found in true deep cycle (80%) units.

If it is rated as "CCA" or "MCA", it is likely a hybrid unit. Any decent RV center or Batteries Plus retail store will have true deep cycle batteries for RV applications. They are more expensive than marine deep cycle batteries.

July 22, 2003 01:43 AM Forum: Equipment Talk

Re: Aperture vs. Seeing - Another Round

Posted By Mike Gibson
Oh boy...here we go! The Sky and Tel article is replete with the usual reasons why the larger scope might be having difficulties, yet these are real world conditions that cannot be ignored.

Near the horizon, my CZ truss Dob flexes a bit, throwing collimation off enough to kill any claim to superiority over the smaller apertures.

Aperture rules, except when it doesn't.

July 23, 2003 02:31 AM Forum: Equipment Talk

Center Spot a Mirror?

Posted By Mike Gibson
Physical center can easily be found using a compass and paper. Carefully draw a circle equal to the mirror's diameter, cut it out, enlarge the pinhole a little and mark the center with a Sharpie marker.

Place an adhesive/glue backed paper reinforcement (also known as a...ooops can't say that here) on the mirror to get a bigger collimation target. Some folks like to blacken the paper ring with a marker.

July 23, 2003 04:10 PM Forum: Equipment Talk

12 Volt Battery Supply

Posted By Mike Gibson
Lots of us are using the yellow 12VDC jump-start batteries or bricks to power our scopes, recommended or not. Just make sure to use a battery with protective breaker/fuse, a fused power cord, and test for correct plug polarity before using it on the LX200 GPS. Meade has been known to solder up things backwards. (Thank Meade for getting rid of the 18V design for older LX200.)

To be fair, Meade can't test every variety of commercial battery combo, but can be reasonably sure of automotive standards for the cigarette lighter or convenience sockets.

July 23, 2003 09:35 PM Forum: Equipment Talk

Equatorial Dobsonian?

Posted By Mike Gibson
Dan - it will work just fine except for the slight CG balance problem in Dob mode. I attached a Losmandy DUP to my 10" Dob's rocker cradle and it worked OK. Would be better with rings and plate as you described.

July 24, 2003 05:11 PM Forum: Equipment Talk

Infinity Focus

Posted By Mike Gibson
Because telescopes do not have infinity focus stops and depth of field takes on a whole new meaning for astro objects. The telescope can move from intra-focal through extra-focal positions with respect to a varying focal plane.

Camera lenses have stops that prevent such focus flexibility for infinity, but as you know macro extensions can be used for close-ups. This applies to telescopes as well.

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