CGEM Telescope Mount

My posts concerning the CGEM telescope mount, curiously, continues to be very popular even though many of them are several years old. By back checking to the referring sites I can read the forum posts which links to my blog pages. I find it very interesting that there seems to be several persons vehemently disagreeing with my conclusions that the CGEM is not an acceptable mount for anything but introductory amateur astrophotography or strictly for use with wide angle lenses.

The interesting thing is when I travel to other posts giving advice (from the very same posters) to any would-be astrophotographer they nearly always advise against the CGEM and similar class of mounts. Instead they nearly always recommend  much more expensive AP and similar class  mounts for any serious astrophotography. The very same conclusions that I arrived at. Actually I also recommended  a much cheaper route which is buying time on remote time-sharing systems which tend to use laboratory grade equipment that can be used for scientific purposes other than strictly making pretty graphic arts pictures.

There are several issues brought up with my criticisms. First, they seem to confuse non-orthogonality between the optical tube and the mount axis, called cone error, with non-orthogonality between the axis. Very different animals, cone error can be corrected, inter-axis orthogonality can only be properly corrected by line-boring in a machine shop.

Second, they seem to think that I was doing my testing with an overloaded mount. Wrong! My 9.25 optical tube was on the ground. When I did my testing it was loaded ONLY with the Orion auto guiding scope which weighed less than ten pounds.

Third, my criticism of comparing the mode of operation of the feedback control DC motors to that of stepper motors. Yes, many servo motors, DC and otherwise, use pulse width modulation to produce an effective DC voltage less than the power supply in order to control motor speed. These pulses are very often several hundreds to several thousands of pulses per second, outside the vibrational frequencies of the mount and scope. My point is that you CANNOT use speed control below the effective voltages in which the CGEM servos operates during guiding. Instead the motors are subjected to strong pulses every second or two, depending on the exposure time of the guide camera. These pulses cause detectable vibrations that reduce resolution, PERIOD!

Hence the usability of imaging unguided with PEC corrections during longer exposure times is a VERY GOOD INDICATOR OF MOUNT QUALITY, or in the case of the CGEM the indicator of the LACK OF QUALITY. The CGEM is NOT PEC CORRECTABLE, Celestron is NOT working on the so-called 8/3 error, despite the continued misinformation supplied by such web fanboy forums.

Fourth, the resolution of any lens, or antennas used in radio telescopes, is dependent on the aperture diameter and the frequencies being observed. So when a 2.5 inch camera lens produces higher resolution than a 9.25 inch diameter optical tube that is supposedly optimized for astrophotography – that is a VERY BIG DEAL!

I could go on and on but the facts remain the same, arguing with fanboys only leaves you as frustrated as trying to use the CGEM mount for astrophotography. Like I said many times before the CGEM is a superlative mount for visual use, but for astrophotography you must lower your expectations or look elsewhere, and that just about says it all.

Epson Stylus Pro 4900 – Fixed Print Head Clog

After being packed away for five months I pulled my Epson Stylus Pro 4900 printer out of moth balls. To my dismay the print heads were all completely clogged. Prior to my packing it away I diligently printed a test print weekly, the Auto Nozzle Check almost always resulted in the printer going into a clean cycle because of a detected clogged nozzle. This ends up using more ink for cleaning than is actually used for printing, sigh, this is a very expensive way to do business since a complete set of HDR inks cost well over $1000, UGH!

Now I am not a professional printer, I usually print sporadically in batches, normally printing several full size prints and panoramas after a photo vacation. This wreaks havoc on the printer heads and ink consumption. I have researched on the web and found that the Epson Stylus Pro x900 series printers are notorious for clogged print heads, the 4900 model in particular. Mine was no exception. So before calling Epson for service I decided to perform some common methods to clean the print heads, note that there is no quick fix for this problem and you will most likely need to adopt a fairly expensive procedure to prevent clogged print heads, especially if you do not print regularly.

First I tried the Windex pad method, surprisingly this partially opened up several of the heads which allowed for at least some ink to move through the heads. The exception, at least at first, were the Green and Orange HDR inks. It was only after six full days of placing the Windex soaked pads under the unparked print head, three times a day, did the Orange an Green heads open up, surprisingly completely, While several other heads were still partially blocked. In fact by this time the print patterns were becoming almost exactly the same from test print to test print, I was forced to move onto more extensive measures.

I ended up purchasing a copy of Epson’s Service and Adjustment program as well as a copy of the service manual which has the instructions for how to use the program. These two items are only made available to Epson service personnel so I think that these items may have been black market, it cost $42 for the both of them but it was still much cheaper than the $1900 Epson will charge to replace the print head which is more expensive than the printer cost new.

I also ended up buying a complete set of refillable ink carts to use for cleaning the entire ink path. The manufacturer also sells cleaning solution but I opted to use the original Windex to fill the ink carts. It is important to fill the carts completely with Windex in order to maintain a positive head of pressure on the tank exit to prevent bubbles in the pre-charge path, this is due to the thinner viscosity of the Windex versus the relatively thick ink.

I also had to buy two extra maintenance tanks as well as a Maintenance Tank Reset Tool, this is because the ink charging and ink draining uses a lot of ink and Windex. The absorbent material needs to be changed after every reset. These absorbent pads can be found on the internet but I opted for much cheaper absorbent feminine products instead. (the reset tool was not supposed to reset a box that was completely full, but mine successfully reset it anyway. So now I have three useable resettable maintenance boxes

Once I swapped out the ink cartridges for the cleaning cartridges I performed an ink charge routine from the Service and Adjustment program. This used up about 122 ml out of the 360 ml capacity of the maintenance tank. I waited an additional four hours and performed a second ink charge routine. Four hours later I reinstalled the ink cartridges and did another ink charge routine to refill the tubes and print heads with ink. After all of this the Maintenance tank was full and had to be cleaned and reset.

I had to do numerous additional cleanings to get the printer to print with ink, I actually ended up doing another ink charge routine on the left side. But I was elated that all but two of the heads were completely free of clogs. YES! The printer transformed from landfill fodder to a functional printer once again.

Is the Epson Stylus Pro worth all of this trouble? My answer is – Hell Yes. I can attest that when this thing works, it prints well. But shame on Epson for not making this knowledge and necessary cleaning tools available to the people who need them most. the maintenance program should not be necessary, in other words it should be available on the service mode from the control panel, and Epson should make available refillable cartridges and cleaning tanks.

Additionally, my initial ink cartridges were all about 90% full when I started but were only about 15% to 20% full in the end. The cost of this adventure: about $700 worth of ink, $285 for the refillable cartridges, $42 for the Service and Adjustment program and Service Manual, $35 for the maintenance boxes, $40 for the maintenance box reset tool. $15 for a box of Kotex pads and a couple of bottles of Windex refills, not to mention shipping charges and the aggravation and week of my life that I will never get back.

On the other hand, I printed one of my images of the spectacularly vibrant fall colors on the St. Croix River and, holy s**t! Those HDR inks Rock! But I just might have to invest in Cone inks to bring the costs down of this inevitable misadventure in the future, expel the ink and fill with cleaning fluid after EVERY time I print out a batch. Shame on you Epson, you forced me into using third party inks from now on. I’ll just have to live with a little less gamut from here on in. You will never make any more money from me from ultra expensive inks and maintenance boxes ever again ;-/

_DSC6000_1_2_3_4_tonemapped_ps**************** update ********

I just thought I would list the amount of ink required to do cleanings and ink charging for the SP 4900:

From the printer control panel:
Normal clean – 3ml
Powerfull Clean – 15ml
Switch Black Inks – 4ml

From the Service Adjustment program:
Ink Charge – 115ml
Ink Eject – 79ml
CL3 Clean – 51ml
CL2 Clean – 18ml
CL1 Clean – 4ml

I would also like to point out something that may have contributed to my clogging problems. In looking closer at the information provided from the ink cart chips, several of the Epson ink carts had a manufacturing date from 2010, these carts were purchased less than one year ago. Most of these carts were purchased from a very large and well respected photography supply store (located in New York with the initials B&H). Now Epson specifications list the shelf life of the ink carts at one year and reduces the ink life to six months from the installation date in the printer. This means that I was sold several ink carts that were a full TWO years beyond their shelf life. I realize that this date is probably when the chips were programmed and may not necessarily reflect the age of the actual ink, but I can’t help but wonder ;-\

Blood Red Moon Eclipse

Isn’t it cool to think that all of the sunrises and sunsets from all over the Earth are all being projected onto the Moon :-)

This one was added 22:00 CDT, two exposure HDR image using Photomatix Pro:



Taken with a Nikon D800, Nikon 400mm with 2.8x teleconverters (1120mm) mounted on a CGEM mount.

Untitled1This shot was taken with a Nikon D3s with and 85mm lens, 3 min intervals.

For the CGEM fanboys – Even if this mount were to have been manufactured perfectly, which I can assure you it was not, the speed of the motor was fast, requiring me to recenter the Moon three times in an hour-and-a-half or it would have been out of frame.

This means that even if the mount could be perfectly aligned with zero error the mount would still need to be continuously guided with significant adjustments with each exposure of the guide scope. If, on the other hand, the motors were speed controlled, rather than position controlled, then after the first few corrections the mount would continuously track correctly. Instead the internal clock incorrectly calculates the estimated position of each of the impulse  movements.

By the way, for the moon to go completely off frame would be a tracking error by well over one degree, while the movement of the moon relative to sidereal time would be 360/28days/24hours or about one-half of a degree per hour. This is approximately the angular width of the Moon per hour.


Self Reflection

There is a very fine line between brilliance and insanity…

Fitter, happier, more productive,
Not drinking too much,
Regular exercise at the gym
(Three days a week),
Getting on better with your associate employee contemporaries,
At ease,
Eating well
(No more microwave dinners and saturated fats),
A patient better driver,
A safer car
(Baby smiling in back seat),
Sleeping well
(No bad dreams),
No paranoia,
Careful to all animals
(Never washing spiders down the plughole),
Keep in contact with old friends
(Enjoy a drink now and then),
Will frequently check credit at (moral) bank (hole in the wall),
Favors for favors,
Fond but not in love,
Charity standing orders,
On Sundays ring road supermarket
(No killing moths or putting boiling water on the ants),
Car wash
(Also on Sundays),
No longer afraid of the dark or midday shadows
Nothing so ridiculously teenage and desperate,
Nothing so childish, at a better pace,
Slower and more calculated,
No chance of escape,
Now self-employed,
Concerned (but powerless),
An empowered and informed member of society
(Pragmatism not idealism),
Will not cry in public,
Less chance of illness,
Tires that grip in the wet
(Shot of baby strapped in back seat),
A good memory,
Still cries at a good film,
Still kisses with saliva,
No longer empty and frantic like a cat tied to a stick,
That’s driven into frozen winter shit
(The ability to laugh at weakness),
Healthier and more productive
A pig in a cage on antibiotics.

I just can’t get enough of radiohead.

Making Carbonless Fuel From Water

Here is a slow motion video cracking (electrolysis)  of water (H2O) into its constituent elements Hydrogen and Oxygen. A great carbonless fuel if someone ever figures out how to crack it more efficiently. The electrode is in saltwater and the electrodes have a potential of 12V drawing a current of 2A.

Just collect the hydrogen and compress it into a cylinder and wall-a! A carbon free emission automobile. Too bad it takes more energy to produce the hydrogen than you can possibly get out of it. It would be an act of insanity to do something like that, oh… wait a minute… that is also true for ethanol production for use in automobiles. ;-{

********* update 2014-09-17 ***************

After an extensive debate on YouTube a commenter decided to delete all of his comments that exemplify the ridiculousness and irrationality of how an idealist (liberal) argues. He obviously has been so humiliated that he had to remove the evidence of his stupidity. Here is a link to a copy of most of the exchange before he deleted it:


The bottom line is that this post displays the academic fallacy in that the academic and scientific communities have been nearly completely silent in that nearly all “green” energy sources cannot now, nor will ever be able to, produce wealth. Instead they consume wealth, as well as polluting more when you consider their entire processes, which is why they nearly all require government subsidies and artificial punitive penalties on those from which wealth can be created, mainly from fossil fuels and nuclear energy sources.

Sorry but throwing an exorbitant amounts of money to the “Big Government” research industry will not spontaneously produce a Mr. Fusion in which we can run our time traveling automobiles on empty beer cans an banana peels.