Posts Made By: Larry Stange

In the process of converting a Vesta webcam for astrophotos a slight bend in the CCD assy board was noted being caused by the microphone pressing against metal housing. Much more serious flaws were then observed after the removal of the microphone, regarding the angle of the CCD and its assy board to the focal plane. The board was not flush to the *square* cast housing surrounding the CCD because the square housing was not flat NOR level!. Without a doubt the threaded lens would have been way off the perpendicular axis of CCD. The CCD error in angle was obvious AFTER it was discovered. Some of the circuit heat could be dissipated from a flat contact of the square housing to the copper ground plane on both sides of the CCD. In short, nothing was true in the metal castings although fairly close.

I sectioned off the square metal casting surrounding the CCD and trued the bottom flat & removed the casting bulges on the top to a height accuracy of .003 inch. The CCD now seats flush to the square casting and the boards copper ground planes now make contact with the casting.

Because my CCD true'ing work had an error of at least .003 inch, I changed my housing design to allow for small corrections of the CCD alignment in the focal plane.

This was accomplished by using 3 nutcerts in a triangular fashion on the housing box(see photo.). The draw tube is tightly seated in a thick aluminium plate which has a rubber sandwich between itself and the housing box. Three adjusting screws compress the rubber adjusting for any tilt which may still be left after the CCD work thus insuring alignment.

To summarize: Everything was done to promote full contact of ALL metal parts for heatsinking. Everything was done to insure the CCD face is truley perpendicular to the focal plane. There is more than enough adjustment range in compressing the semi-hard rubber to handle any future problems.

The box is not finished by a long shot because before any electronic mod's are done I want to examine what I think may be the REAL heat problem in webcams....i.e., after a 1 hour test of running the CCD in semi-light conditions with the box open, ALL of the heat was coming from the PROCESSORS, not the CCD. This means I may cut minature heat sinks from a computer processor down to postage stamp size and epoxy them on the two processors in the CCD...IF I can find a heat conductive epoxy and add a quiet fan etc.

I know I'm on the right track because now for the first time I can obtain sharp focus on a white window frame about 1/8 mile away in BOTH the vertical and horizontal axis. Before I could focus on the vertical OR the horizontal, but could not get them both together. Photo above illustrates some of the points I referred too. -LarryS

P.S. Plumbing tube is chrome plated brass 1.252 in dia. It is the EXACT fit to my Celestron camera adapter without ANY play in the seating! Everything inside tube is flat blacked including inside the lttle square housing. :-)

Many decades ago there was published some theoretical readings on an experiment conducted during the 2nd World War on making ships invisible by internally generated high gauss magnetic fields(bending light). 30 yrs. later a movie alluded to this. What ever happened to this *partially successful* endeavor?. *I remember hearing ship image "shimmered".

On a 2nd note, has anyone ever plotted major scientific advancement over time to see if unexplained anamolies are present to account for possible outside influence?. You're right!........BACK TO ROSWELL & Area 51. ZZzzoooom! Zooom!.

I expected far better detail in prime focus without any lenses or filters between the Philips Vesta 675K and the Celestron 6" refractor lens.

The telescope is operating out of an open upstairs window and the moon shots can only be taken at 5-6 PM(twilight) at 15 to 30 degrees above horizon(due to roof eaves) over a City.

The computer 15" monitor at 800 X 600 shows a small section of the moon at full screen when the program QCfocus is used. The photo was taken of an .AVI frame with a screen capture utility that produces .BMP. Adobe Home Edition converted the .BMP to .JPG for this forum. Color and blotchiness resulted from these conversion. But this is not my concern. The lack of sharp focus is.

I had thought that A-Focal would create undesireable results due to the extra lenses involved. Now I am not sure.....

Under these circumstances....is this pic reasonable of not having sharp image and contrast?. The image on the monitor never stops changing going from blurr to more blur, especially if I move my arms on table, walk, or house vibrates due to the wood floors. -The photo has NOT been touched up...It is the best I get.

The 3 methods of CCD imaging compared. Prime focus, A-focal, and eyepiece projection.

What free program can take an .avi, break it up into a lot of .bmp's so that a long fuzzy sequence of .avi astrophotos can be deleted leaving what might be fairly sharp .bmp's to be stacked?. And, I suppose there is no way to reassemble the .bmp's back into a single .avi to make it easier?.

All of us are aware of the mercury parabola for astronomical work.

There should be a way to utilize this principle with another substance like a slow cure epoxy that can be surface bonded with a second substance that can be aluminized. Temperature control for finished mirror not being an issue at this time.

Every garage could have a mirror up to 1 meter in diameter in process. Focal length set by rotational speed.

There should be enough brain payload & freight to accomplish this in a practical manner here on this forum.

It is difficult removing old inaccurate/assumed concepts. I am now questioning all my pre-concieved notions. Your combined inputs will help clear away mental rubble and put me on the path of....(dare I say it?,)CCD righteousness. :-)

I have found Astro Video will not accept Connectix color quickcam .avi in "full image uncompressed mode". To enable stacking etc. it is necessary to use the Connectix default compressed image format or try using other software modes that are a part of Connectix software options.

I am not sure how this effects the "stack sharpest image" program of Astro Video.....anyone know?. -LarryS.

An experimental mask design incorporating two hour-glass configurations.(e.g., two black widow spider symbols). I am not completely sure of what to expect on a planet or star but the photo shows the results of focusing on a window frame 1/8 mile away. The central image is out of focus deliberately to show starting point. The final result of bringing everything together is shown in the lower right hand corner. By dropping the intensity level of the camera it resolved down quite close to perfect. The hour-glasses are not perfect triangles(I used an IC drafting template for a guide), cutting the cardboard. -LarryS.(Philips Color Pic)

Being obsessed with finding any easy Hartmann way to pinpoint critical focus for a CCD....I offer the second of TWO variations (just completed). Both will be tested as soon as the rain & fog stops obliterating the sky.

Any guesses on what these two will do on Stars, Planets, & the Moon, when critical focus is approached?.

The 2nd one has two disks suspended by fine black thread in the center of the Hartmann holes. The other has twin triangles. PaintShop dwg. is poor.

I believe we can test CCD flatness to the optical plane AND collimation at the same time by rotating the CCD 360 degrees while observing the center shift of an optical target such as a point source or a window frame "X" while viewing image on a computer screen or CCD software.

I found I have shift in my refractor....next step is to isolate whether it is collimation or CCD flatness. If I cannot adjust it out with CCD positioning....then it is a collimation problem. Larry S.
-(copy of sorts posted on QCUIAG message board.)