MarsG76

Yes that is frustrating, but unfortunately that a part of the hobby.... if it worked every time and was easy than it wouldn't be a challenge and everyone would be imaging.... I myself was presented with "NO OPERATING SYSTEM FOUND" on my obsy laptop, than after sorting that out... no USB was recognized.... happens. Relax, calm down and try again in a night or two...

Oh ow.... here come sleepless night, lethargic days, empty bank accounts but rewarding images you can call your own.... you own images that will cost a lot.... but you'll never regret it. Great pictures you've already imaged.....

I had a chance to play with PEC for a few nights. Trained, re-trained and averaged single night to various nights of training runs.... I compared the RMS guiding accuracy at various times with both PEC enabled and disabled, my results are as follows. I tested PEC at 2032mm focal length using my 8" SCT on the CGEM mount with PEC averaged one night of PEC training runs, multiple nights worth of PEC training runs and with PEC off. I let it run for 15 minutes and read the average RMS. I found that PHD2 reported the lowest RMS correcting with the PEC OFF!!!!!... around 0.5" RMS tonight.. mind you that the difference between the PEC enabled and disabled was only a matter of around 0.05"-0.1" between the tests... seems like it's hardly worth while.... How disappointing as currently it seems like that there is not only no improvement with PEC but it can actually make tracking (very slightly) worse?? Did anyone have a similar experience with PEC??? Attached are screen grabs on my PEC training averaged graphs. PEC training was performed by the Celestron ASCOM driver connected to NexRemote virtual COM port in PHD2 and PECTool connected directly to NexRemote. PHD2 was calibraed and allowed to guide the guide star as PECTool was recording the RA pulses. Any input into what I might be doing wrong and hence the disappointing PEC result is welcome.... Clear skies, MG

Thanks for he reply Craig, My hand controller is the non-plus version 4.21 (currently), bought in 2010. I am already a member of TeamCelestron and have the BINS, but the three files are named as CGE, NXS and SLT... CGEpro, NexStar and SLT??? No GEM, which is the bin label used in the past for CGEM firmware updates. Am I mistaken thinking that CGE bin file only works on CGE Pro and won't work with the CGEM? Perhaps I can just wait for the official v4 firmware update. Thank you, Mariusz

Currently clouds.... so 0 ?

Do you know if any of these updates will work with the CGEM?

Do you know if any of these updates will work with the CGEM?

Thanks

Hello Astronomers, It's been quite a while since I had time to play with astro toys... even my cooling project, even though it is somewhat cooling the DSLR, is still a project in progress... It's been a while after the CGEM firmware has been updated and has reportedly fixed the broken PEC, I decided that it was time to play with PEC training and try and improve the amount of DSO detail I capture, particularly at 2000mm focal length. As is natural with this hobby, it couldn't have been straight forward, no.. it had to have its problems and obstacles to overcome, really there was only one problem, but a "deep buried" one... When I initiated PEC record, the mount just kept slewing toward the east on the RA axis without end until it hit the mount limit... simply put, the mount couldn't find the index point. Looking at the TeamCelestron site, I found a post where a CGEM DX user has the same problem, and Derik, one of the firmware engineers, suggested that the mount had a faulty sensor or even a Motor Board fault... so at this point I thought that I might have to live without PEC or buy a new mount... but ultimately I kept thinking about what the issue could be... I didn't want to let this go I thought that I'd swap the RA and DEC motors to see if this would make a difference but on pulling out the MC board and removing the RA motor, I very quickly realised that there is a extra ring or plate on the RA motor with a notch cut into it moving in between a U black... obviously this is the index sensor and swapping the motors would not work. The other thing I noticed is that the index ring and U sensor were covered in grease so I cleaned the grease off the motor, gears and sensor using isopropyl alcohol... re greased the gear cogs and reassembled the mount... NOW PEC was working, initiated PEC record and it found the index mark within a second... wooohoo The next clear night, last night, I setup NexRemote on the COM port, with a virtual COM port setup and connected PECTool directly to NexRemote. I setup and calibrated the scope completely off the laptop, and once it was ready, I ran guiding using the ASCOM celestron driver connected to the NexRemote virtual port and commenced autoguiding on PHD2. I ran PEC training in PECTools and let it repeat for 14 runs. I uploaded the averaged corrections from all 14 runs to the mount... downloaded the graph back from the mount successfully verifying that PEC program is in the CGEM memory. Now I was ready to do a autoguiding accuracy test comparison with and without PEC but... as it should be expected... clouds!!! I parked the scope and powered down the observatory, ready for the next clear night, ready for a detailed test and perhaps a imaging session with PEC running, and it hopefully making a noticeable difference to guiding and sub quality... to be continued. Clear skies, MG

A Canon 40D, the one pictured.

A 32° on the sensor would have me very joyous... even might be too much, since a hot night is around 30°C here but generally summer is around the 22-24°C and winter 9-15°C at night, so either way I'd have to use the temperature controller to keep the sensor at the 5°C for which I'm aiming. Don't want to fight frosted sensors.

I guess that is the case if the peltier is sitting directly on the sensor... but what about when the heat extraction is by using a copper plate which constantly fights outside heating sources such as the circuitry.. I'm guessing that the colder the better... currently I have a 20 degree heat up simply to the copper passing through the camera in a 24/25 degree ambient temp... hence my aim for -20 at the peltier side.

I don't trust the EXIF, I have a thin NTC between the sensor and the cold finger giving me an actual reading.

Hello all.... Good news is that after I filled the inside of the camera with foam strips, sealed the cold finger entrance with expanding foam and placed silica gel into the card compartment, I could image all night for quite a few nights with no condensation problems.... With the on going quest to freeze my 40D sensor while exposing subs, I constructed the same setup to measure the temperature of the peltiers with the surrent setup... the result is that it did not got below 4.2 degrees (from an ambience of around 20), and that temperature was hit in about 20 minutes... the dilemma is that with the distance between the cooling system and the sensor, the cold finger passing through the inside of the camera, seems to heat up by around 20 degrees.. resulting in the actual sensor temperature hovering at around ambient temperature while exposing (give or take a degree or two). Even though the system currently is a noticeable improvement over when the camera was uncooled, ultimately I would like to have the sensor at around 5 degrees. As the next stage in experimenting, I got a bigger heat sink, the CoolerMaster 212X, added a second fan to it and attached two peltier stacked, the primary TEC powered with 12V and the secondary with 5V... the temperature drop was 44 degrees.. went down to -19 degrees from and ambiance of 25... at this level, even if the cold finger would heat up by 20 degrees, the sensor would still be at 4.. so my target would be reached.... The other problem is implementation since thee 212X is a lot bigger, but weighs the same as my current setup with the two TECs and two P4 heatsinks, so it seems like the heatsink might be unbalanced unless I stabilize it. To be continued...

Everything is tight with heat transfer paste... the NTC should report the accurate temperature since its tight against the copper plate, even if the sensor might not be to the temperature.. but believe me, its all very tight... I'm missing something.....

That is one neat and tidy project.. BUT... look at the tiny heat sink with the tiny fan he is using.. HOW does ho go from 30 deg to 0 with that??? Got me thinking.. he stated that he is powering the kit with a 4A PSU.... I did some measurements and I'm running 8Amps on the two TECs, fans, and temperatures controller, but still stopping around 10 degrees below ambient when the camera is OFF... when on it goes down from 25 to 18 as before so I thought I'll setup other TECs on a massive heat sink and fan as well as measure the temperature of my very first cooling project... The Big heatsink has the TEC sandwitched between it and a small heat sink, the NTC in the middle grill and the whole thing sitting on a Styrofoam block..... the resulting lowest te mperature is 18.2... thats when the TEC is hooked up to a 50A 12V PSU and the heat sink is not even getting warm, so heat dissipation is definitely effective. The second setup, the first project, draws 9 amps for the two peltiers and fans, the heat sinks get quite warm, and the result lowest temperature is... 13.1 Both of these cooled items, small heat sink or the case of the DMK41 are WET with dew.... Whats going on? I cant get below 11.7 after about 60 minutes of cooling on the two TECs on the DMK but thats nowhere near freezing.... it reached 13.1 in 20 minutes than slowly went to 11.7... also the DMK is not powered... The fan on the big heatsink has a speed control pot and the funny thing I noticed is that when I had it running max speed the temperature didn't drop below 18, but when I turned it to minimum speed, quite quickly, the speed dropped to 16 and stopped there... so I disconnected one of the extra fans on the DSLR, the bottom one of which extracted air from the fins and seeing if this will make any difference to the lowest temperature. What am I missing?

Very interesting... initially I thought that perhaps I'm not dissipating enough of the peltier heat, but it is just warm to touch so I don't think that heat bleeding on the peltiers is the problem... BUT I'm juggling now whether I should re-wire the two pletiers in series, this way they'll both run at half voltage and perhaps increase the efficiency of the cooling with less heating.... and OR my copper plate it too thin, (1.3mm thick) to effectively extract the heat from the sensor?? Which would be a problem because there is no way I can fit a thicker plate inside the camera, already I had to squeeze the unit shut, so I'd have to live with the 32 degrees plus down to ambient (which does improve slightly). I'm using ebay 12706 peltiers from China, so perhaps they're not as good as they should be??? Get what you pay for?? My other option is to wait until winter and see how far the camera is cooled to when the climate is not so hot... night time 25 degrees C but feels more like 30... and so the cooling is struggling.... Either way, so far I do have an improvement so it's a start.... and good news is that the camera survived another night...

Hi All, I modded another 40D... this time I squeezed very think foam sheets on the cold finger and into gaps where I could, I sprayed expanding foam into the gap where the copper plate goes into the camera, inserted silica gel packets into the card compartment, I added a thin NTC sensor between the sensor and the cold finger for accurate sensor temperature reading and added another fan to help dissipate the heat off the heat sinks. I had the camera running for 2 nights at 80% humidity and a dew point temp of around 20 degrees.. roughly the same conditions as during the nights when I lost my camera before... and this time the camera survived, so perhaps the foam did the trick, thanks for the suggestion @Stub Mandrel and @Thalestris24.... time will tell if my camera can survive the dew.... I'll tell you that with the foam inside the whole assembly is TIGHT.... very tight.... Here are my findings... when I'm exposing my subs at ISO1600, a 30 minute (15 minute also) settles at about 1 degree below ambient according to the NTC between the sensor and the cold plate.... when not exposing but the camera is on than it falls only about 8-9 degrees below ambient... when the camera is off than I get to about 10-12 degrees below ambient. the ambient temperature is 25 degrees C at midnight being summer time.... Now the EXIF temperature reported by APT coincides with the NTC reading... so the EXIF temperature on cameras looks to be accurate. When exposing the same ISO and duration subs with the cooling turned off the sensor temperature rises to 32-34 degrees C (actually seen it go up to 38 once)... so I guess its an improvement of around 8-10 degrees... So my question is do these numbers look right, considering the ambient temperature and considering that I do have two peltiers running and cooling the copper plate back to back which are quite well insulated and the heatsinks are not too warm at all with all of the fans blowing and sucking air through them? I read about how some of you get ice forming and reach -5 degrees etc, is that because you're cooling your camera at a much lower ambient temperature to begin with?

Even though it's a bit over the budget you have mentioned... I couldn't recommend the Celestron 8SE enough... that scope will serve you for ages.. mine is around 10 years old and it still gives me some of the best views most nights.. all except the RARE clearest nights, it out performs my 14" dob on planets....

Thank you for they reply... I do have questions.. Adding silica gel inside wouldn't hurt?. I sprayed my main PCB with Polyurethane conform so I might not need the hot glue? My other question is, if there is foam up against the copper plate inside and blocking the entrance into the body, won't it just get saturated with moisture that currently seems to accumulate and drip down inside the camera causing the havoc and cause the same effect just later in the night?