FrenchyArnaud

I am indeed. In fact I have build a 2nd one, with a nema17, for my modify C8N which is currently on the pier. Took me under an hour to do this 2nd one, it is actually real easy. I'll take pic of the 130 AF shortly.

Hi César, Dust on the sensor - yes I guess it's possible but that does not sound like a big problem to me. Flat frames are designed for that and cleaning is not difficult. So far, no issue with this though. Yes, the camera is permanently on the telescope, itself on a pier, and has been continuously in service since this post, without issues. Your english is at least as good as mine, (I am french) I guess in those days of international internet and world-wide hobbyist collaboration noone will care if you make a language mistake (noone ever said anything to me anyway!)

Hi guys! i captured a small region of Ha , possibly a planetary neb at RA: 0 01 40 Dec: 64 38 00, near NGC7822 in Cepheus. It shows on Stellarium as a background image but with no mention at all, and it does not solve on telescopius either. (Well, it solves and appears as background imagebut does not ID the object). Shows as a noticeable disc about 20" in diameter, more signal in Ha than Rgb. Any idea how I can get the ref/name for it?

For the interference, the gyro estimates the regularity of the motion by taking point measurements. If the speed shows a tendancy to drop even minimally, then resumes brutally AND triggers the vibration sensor, it judges that something "catches" and releases. Hence, snag. Vibrations without speed change: repeated small to medium values are considered as wind, high random values as interference (cat, sthg that fell or gave way etc) if the flip goes normally, the gyro can infere it (inverted positional values = flip) but if the resulting values are too far off the invert of the initial, then an alarm is sent. I am still developping the soft. part.

Ok! So, the first prototype is working and undergoing real life tests... There has been quite a few adjustements of the concept but it still is tiny (That's a 4cm * 6cm circuit board) and fits in a tiny casing the size of a big box of matches. It returns a butload of values including spatial X Y Z positions, and X Y Z absolute motions, a very precise array of temperature (air / module / OTA) , a rain detector, and so forth. All in all, about 20 variables are sampled every 10 seconds (can be changed from 1 to 3600secs) and are sent to a python module which itself does some serious math on the raw data to decide if everything is as it should, including dew point, frost, snag, unexplained vibrations, obvious pointing errors, fog, rain, condensation. If everything is not as it should, this reporting gizmo sends an notification on your phone, which can be either of the "just info" type or "Big alarm!" if it finds that it is pointing downward and filling with water, aka telescope in the swimming pool because the neighbour's saint bernard is on drugs. In HighPriority setting, the notification will ring your phone even if it's on silent, every 1 to 10 minutes (can be changed too), until you get your lazy ##### out of bed, acknowledge the notification andgo check on what is wrong (typically, unexpected rain) The system can anticipate weather events with a reasonnable short term reliability (about an hour) and send low level notifs informing of he increase in risk for rain, fog, snow and frost. It also alerts you if the tracking rate and tracking attitude is obviously inconsistent with astrophotography (pointing below horizon, stoppes, too slow...) and can infere cable snags, low laptop battery etc etc.... There is still quite a lot of dev to be made before releasing the complete project but a look at the config file will give you a good idea where this is going (for the diy maniacs like me). It's here : https://github.com/FrenchyArnaud/GuardianAngel/blob/main/config.py

Ok, so first, the name "guardian Angel" is temporary - I was not able to come up with anything better since I started this DIY project a few weeks ago. The idea is to have an independant "observer" or "monitor", that is able to take measurements in real time of all the basic stuff you would normally do by hand while doing AP, and raise an alert, an alarm, or simply write a log, should anything go wrong with the pier, like an obvious discrepancy between slew position and actual position of the OTA, unexpected rain etc. It's currently being developped and is well on its way. The core is an Arduino Nano paired with a GSM module (SIM800L) and a microSD card module on a protoPCB, which takes measures as soon as the pier is powered on. These measures are provided by : - A rain detector (LM393 / FR-04 50mm*40mm) - A gyroscope (MPU6050) - A vibration detector (SW420) - A barometer (BMP180) - A temp/humidity sensor (DHT11) As it stands now , the Guardian is able to detect when: - the weather is about to degrade unexpectedly (for instance, increase in temp and humidity + drop of atm. pressure indicating the approach of a local thunderstorm) - something is interfering with the OTA (animal, wind, snag..) - rain, snow or excess condensation are appearing (and can differentiate using weather computations based on baro/temp/humidity values) - the slew is noticeably different from theoretical values (every once in a while my scope will point straight up and stick there for no obvious reason) - a meridian flip went haywire - the scope stops moving but is not in park position, etc. It also automatically sends a handshake sms to my phone when I power the pier on, to confirm that all systems and probes (and the GSM link itself) have booted normally, and (will) interface with NINA to send a GoodNight message with a status report once NINA has finished its nightly sequence. When any of these happen, the severity of the issue is evaluated, and depending on the situation, the Guardian will simply log the event, send a text to my phone with the basic data/infos (and wait for an answer and instructions) and, if no response arrives within 10 minutes, it will either send another text or, if there is an emergency (noticeable rain for instance) , it will call my phone (which rings with an alarm ringtone for this specific contact even if my phone is on silent) Basically, this gadget will do all the basic monitoring to avoid wasting a full night for a stupid thing that is easily detected but would require to stay up at night or to half sleep with an eye on the computer from the bed. If anyone is interested, I'll post the schematics, parts list, firmware, software and docs here when it is sufficiently stable and complete. For now, it's only an advanced prototype. NB : it POINTS OUT issues and pulls you out of bed if needed, it does not take any action - for now. As a second phase of dev, I am considering having it able to cut all electrics on the pier (for emergency stops) either in response to a command (sent by SMS) or off its own initiative, using a master relay., and a few other possibilities of direct action. It is standalone and does not require USB/WIFI connexion because its main function is to be a totally redundant system that oversees the physical reality of the pier's behaviour independantly of what the session manager and the telescope controller are doing. Any input, remark, suggestion or question welcome.

This cretin always is 😆🤣

Sometimes it's easy to forget where you are coming from, especially how uneducated you were and how poorly you chose your gear when you first started. That's true for any hobby or job that has a steep learning curve but it's especially true of astronomy and even more of astrophotography. That's me, my very first scope and my current (hopefully last) one. My very first scope was a Celestron 114LCM. When I dragged it out of storage for this picture, I thought the tripod had broken... Nope, that's how it's designed. It's just super flimsy by my current standards. The idea that at some point I did indeed shove a DSLR on that is to be fair, nothing short of embarassing. The fact that I was SURE this was the best toy EVER and nothing could ever possibly beat it, is even worse. If I had any pride I would be blushing. Today I am lucky enough to have a pier, "marginally" more aperture, everything is computorized, automated and piloted from indoors, and I take 10mins subexposures while watching TV and stuffing my face with french fries, trusting the rig I have build bit by bit over the course of nearly a decade. It's 100% DIY, second hand, duct tape and 15yo ebay stuff, but it works. I am absolutely SURE this is the best toy EVER and nothing can ever possibly beat it. With this first 114LCM scope I would spend hours trying to "3 star align", to actually get a target in the frame, steaming in rage about poor and inconsistent focus, and I would get get a sense of accomplishment with a blurry, trailed, out of focus 20 second picture. How things change! I am not sure I would have the courage now to go again through the whole learning curve. I guess astrophotography is, eventually, a good measure of a personal journey: it tells how stubborn and objective-driven you are. How many scopes abandonned in garages because the results were not good enough out of the box? How many "passions" permanently squashed after 2 frustrating nights? You know what did not change? I still remember the first time I saw Saturn's rings like it was yesterday. Now, that's a driving force! When my friends try to understand why I want to get images so badly, here is my answer : I don't. If I wanted to get good images, I'd google them. It'd be way faster, way less frustrating, way less expensive, it'd protect my sleeping time and the results would be so much better! But as it happens, I just love the problem-solving process AP never fails to bring, and the excitment of seeing something new for myself. Let's raise a glass and have a toast to clouds, dew, dead batteries, refraction limits, obscure pixel scales, the neighbours automatic porch light, planes, unexpected showers, wind, collimation nightmares, sattelites, polar alignment horrors, high altitude turbulence, heat waves, mist,ground convection, and the occasional trip-on-the-cable-in-the-dark mishap 🥳🍻🥂 Without all of them, even your best image would be worth jack. Without your first terrible pic on your first terrible gear, ex newbee you would have nothing to brag about. Enjoy the frustration, it says you are on the right track!

I like this ! Great idea. Investigating

Maybe 🤔 but that still hurts a bit and if I was to take that road I'd have a better time buying directly the 8" newt/eq cover, which is barely more expensive. Of course it would not go all the way down but low enough I guess... I am just a bit gutted that i had found a heavy duty bbq cover (perfect fit) for the 130pds for £20 and that the extra 3" is gonna cost me £200 😐

I used to have a 130PDS on my pier with a heavy duty bbq cover which fitted perfectly. But I changed the 130 for an 8" (same dimensions as 200PDS) and of course the cover is now way too small which forces me into ugly and only partly safe faffing with tarp. I am enquiring to have a custom made cover but the quotes so far are eyewatering! How did you guys sort this? Surely I am not the first one to come across that issue...

Ooops. Corrected 🤭

For the curious, here is the full log after complete reassembly. 20x 180s with 30s interruption in between exposures, iso 800, fan off, followed by a 3mins pause with fan on, 20x 180s with 30s interruption in between exposures, iso 800, fan on. I think the figures speak for themselves. Ambient : 23C throughout. 2000/01/01 00:04:07 2023-08-13_15-38-27__25c_180.00s_0000.cr2 : M 181s ISO:800 Canon 550D Temp:25C NR:off 2000/01/01 00:07:39 2023-08-13_15-42-00__29c_180.00s_0001.cr2 : M 181s ISO:800 Canon 550D Temp:29C NR:off 2000/01/01 00:11:13 2023-08-13_15-45-33__31c_180.00s_0002.cr2 : M 181s ISO:800 Canon 550D Temp:31C NR:off 2000/01/01 00:14:46 2023-08-13_15-49-06__32c_180.00s_0003.cr2 : M 181s ISO:800 Canon 550D Temp:32C NR:off 2000/01/01 00:18:19 2023-08-13_15-52-39__33c_180.00s_0004.cr2 : M 181s ISO:800 Canon 550D Temp:33C NR:off 2000/01/01 00:21:52 2023-08-13_15-56-13__34c_180.00s_0005.cr2 : M 181s ISO:800 Canon 550D Temp:34C NR:off 2000/01/01 00:25:26 2023-08-13_15-59-46__34c_180.00s_0006.cr2 : M 181s ISO:800 Canon 550D Temp:34C NR:off 2000/01/01 00:28:59 2023-08-13_16-03-19__35c_180.00s_0007.cr2 : M 181s ISO:800 Canon 550D Temp:35C NR:off 2000/01/01 00:32:32 2023-08-13_16-06-53__36c_180.00s_0008.cr2 : M 181s ISO:800 Canon 550D Temp:36C NR:off 2000/01/01 00:36:06 2023-08-13_16-10-26__36c_180.00s_0009.cr2 : M 181s ISO:800 Canon 550D Temp:36C NR:off 2000/01/01 00:39:39 2023-08-13_16-13-59__34c_180.00s_0010.cr2 : M 181s ISO:800 Canon 550D Temp:34C NR:off 2000/01/01 00:43:12 2023-08-13_16-17-32__37c_180.00s_0011.cr2 : M 181s ISO:800 Canon 550D Temp:37C NR:off 2000/01/01 00:46:45 2023-08-13_16-21-06__37c_180.00s_0012.cr2 : M 181s ISO:800 Canon 550D Temp:37C NR:off 2000/01/01 00:50:19 2023-08-13_16-24-39__37c_180.00s_0013.cr2 : M 181s ISO:800 Canon 550D Temp:37C NR:off 2000/01/01 00:53:52 2023-08-13_16-28-12__38c_180.00s_0014.cr2 : M 181s ISO:800 Canon 550D Temp:38C NR:off 2000/01/01 00:57:25 2023-08-13_16-31-45__35c_180.00s_0015.cr2 : M 181s ISO:800 Canon 550D Temp:35C NR:off 2000/01/01 01:00:58 2023-08-13_16-35-18__38c_180.00s_0016.cr2 : M 181s ISO:800 Canon 550D Temp:38C NR:off 2000/01/01 01:04:31 2023-08-13_16-38-52__38c_180.00s_0017.cr2 : M 181s ISO:800 Canon 550D Temp:38C NR:off 2000/01/01 01:08:05 2023-08-13_16-42-25__38c_180.00s_0018.cr2 : M 181s ISO:800 Canon 550D Temp:38C NR:off 2000/01/01 01:11:38 2023-08-13_16-45-58__38c_180.00s_0019.cr2 : M 181s ISO:800 Canon 550D Temp:38C NR:off 2000/01/01 01:24:23 2023-08-13_16-58-43__31c_180.00s_0000.cr2 : M 181s ISO:800 Canon 550D Temp:31C NR:off 2000/01/01 01:27:56 2023-08-13_17-02-17__29c_180.00s_0001.cr2 : M 181s ISO:800 Canon 550D Temp:29C NR:off 2000/01/01 01:31:30 2023-08-13_17-05-50__28c_180.00s_0002.cr2 : M 181s ISO:800 Canon 550D Temp:28C NR:off 2000/01/01 01:35:02 2023-08-13_17-09-22__27c_180.00s_0003.cr2 : M 181s ISO:800 Canon 550D Temp:27C NR:off 2000/01/01 01:38:34 2023-08-13_17-12-55__27c_180.00s_0004.cr2 : M 181s ISO:800 Canon 550D Temp:27C NR:off 2000/01/01 01:42:07 2023-08-13_17-16-27__26c_180.00s_0005.cr2 : M 181s ISO:800 Canon 550D Temp:26C NR:off 2000/01/01 01:45:39 2023-08-13_17-19-59__26c_180.00s_0006.cr2 : M 181s ISO:800 Canon 550D Temp:26C NR:off 2000/01/01 01:49:11 2023-08-13_17-23-32__26c_180.00s_0007.cr2 : M 181s ISO:800 Canon 550D Temp:26C NR:off 2000/01/01 01:52:44 2023-08-13_17-27-04__26c_180.00s_0008.cr2 : M 181s ISO:800 Canon 550D Temp:26C NR:off 2000/01/01 01:56:16 2023-08-13_17-30-36__26c_180.00s_0009.cr2 : M 181s ISO:800 Canon 550D Temp:26C NR:off 2000/01/01 01:59:49 2023-08-13_17-34-09__26c_180.00s_0010.cr2 : M 181s ISO:800 Canon 550D Temp:26C NR:off 2000/01/01 02:03:21 2023-08-13_17-37-41__26c_180.00s_0011.cr2 : M 181s ISO:800 Canon 550D Temp:26C NR:off 2000/01/01 02:06:53 2023-08-13_17-41-13__26c_180.00s_0012.cr2 : M 181s ISO:800 Canon 550D Temp:26C NR:off 2000/01/01 02:10:25 2023-08-13_17-44-46__26c_180.00s_0013.cr2 : M 181s ISO:800 Canon 550D Temp:26C NR:off 2000/01/01 02:13:58 2023-08-13_17-48-18__26c_180.00s_0014.cr2 : M 181s ISO:800 Canon 550D Temp:26C NR:off 2000/01/01 02:17:30 2023-08-13_17-51-51__26c_180.00s_0015.cr2 : M 181s ISO:800 Canon 550D Temp:26C NR:off 2000/01/01 02:21:03 2023-08-13_17-55-23__26c_180.00s_0016.cr2 : M 181s ISO:800 Canon 550D Temp:26C NR:off 2000/01/01 02:24:35 2023-08-13_17-58-55__26c_180.00s_0017.cr2 : M 181s ISO:800 Canon 550D Temp:26C NR:off 2000/01/01 02:28:07 2023-08-13_18-02-27__26c_180.00s_0018.cr2 : M 181s ISO:800 Canon 550D Temp:26C NR:off 2000/01/01 02:31:39 2023-08-13_18-06-00__26c_180.00s_0019.cr2 : M 181s ISO:800 Canon 550D Temp:26C NR:off

As my 2007 canon 450D (Rebel T1i) is beginning to show signs of decay (hanging randomly, data corrupted...) I treated myself to a serious upgrade (just kidding) , a 2010 canon 550D (Rebel T2i / Kiss X4). Sold for spares or repairs. For £50. S&R because the flash is stuck but guess what? I don't really need that, do I. I did the full spectrum mod and decided to deactivate the back screen and buttons and not even put it back on the camera to help with heat dissipation. At that point it occurred to me that the main problem with DSLRs, cooling, is due not to the heat produced by the sensor, but to the heat not being evacuated because the skin of DSLR is a thick plastic and the heat just accumulates. The problem here is obviously that the thermal noise increases significantly between the first and the last exposure; considering that dark/thermal noise doubles for every extra 6C, it follows that the noise increases to 800% of its specifications value. It becomes a mess to calibrate out and the dynamic range of the sensor crashes down several steps. Because of that, some time ago I built a cooled box for my modded canon 450D. It works beautifully and gets the sensor a solid 12C below ambiant, but there are a few caviats, so I use it only on really warm days And that got me thinking. All it would take is a proper ventilation of the INSIDE of the camera (instead of outside cooling in a box) to prevent the temperature from rising in the first place. Limiting the increase to 10 or 12 C above ambient instead of 15 or 20, I could cut thermal noise by half or more. So I did just that, without real conviction because it looked so obvious and simple that I could not really believe it would make a notable difference – but even 3 or 4C less would be a positive thing and the mod seemed really very, very easy so what is the downside? After a few tests and tinkering I saw that : - the sensor temperature in a stock DSLR tends to increase by about 1C per minute of sensor activity and settles usually around +15C to +20C (considering ambient temperature as the base line) In other words, with 60s exposures, at 15C air temperature at night, typically the first sub will be at 16C, the second at 17C, 18... all the way up to somewhere between 30C and 35C. At that point, the temperature curve flattens because the difference between inside and outside the camera is enough for equilibrium, so your telescope does not spontaneously catch up on fire. - The temperature increases the fastest in the enclosed camera unsurprisingly, but decreased the fastest with a ducted fan, that is, decreases faster with the back on but air forced through than with a totally open back, even fanned. I guess it's because the forced air when ducted also seeps under the electronics. The first results were encouraging so I just went ahead. (Vertical : temp of sensor above ambient, fan started at exp #12, red : cooling effect) Before reassembling and after I had tested that everyting was working fine, I disassembled everything within the back, including the buttons, and marked the opening of the fan. I chose a 40mm, 5V, 160mA fan mostly because I have a bunch of these in my electronics drawers. On a 3.7V, 5000mA 18650 battery it can run for days at once. Then I dremel'd it open I separated the buttons and discarded the round selector (that will be the air outlet) I glued the fan in place, and glued the other buttons to plug all holes (but NOT the round selector) Then I painted a thick black coat on each side or the glass and behind the buttons (to avoid light leaks) I also installed 2 tiny heat sinks on the shield of the sensor. Not sure they'll help a lot but it cannot hurt. Then I pushed the back into place and plugged a temporary battery to test the efficiency of the air circulation. finally I glued a battery holder to make it neat(ish). And now it's time for measures. This is the first set of measures. The temperature floor ( zero) is in fact the ambient temp here. Namely 24C (it was muggy yesterday). Each exposure was 120s at 800iso. You can see that after 12 subs, the temp flattens out at around +14C. By the end f exposure #12, I turned the fan on. The red bars actually show the decrease in temp. The first sub was still at the same temperature but after that, decreased rapidly to settle at around +4 ,+5C. That is -10C from normal functioning temperature! Needless to say, I was well chuffed with that. But then it occurred to me, look at the blue bars : clearly the fan is cooling FASTER than the electronics are heating. So I made a NINA sequence to redo the SAME test but this time, with a mandatory 30s pause between exposures, hoping to keep the sensor as close to ambient as possible. So, 120s exp at 800iso, 30s wait, repeat 20x, switch the fan half way through. Here are the final results : Clearly this little fan offers a MASSIVE thermal advantage - the temperature now settles almost 12C below normal functioning temp, 1 or 2C above ambient, which is obviously a surprisingly massive improvement!!! Does it translate into less dark noise? Here are two 400% zoomed in, +4 stops darks made on my desk (23.5C ambient), 120s, 800iso. One is fan'd and consequently at 25C (+1.5C) the other not fan'd, and consequently at 38C (+14.5C) No cigar for guessing which is which. The only difference is the 40mm fan. That's a very simple mod; it's not for everyone of course as it precludes using the dslr any other way than as a computer-piloted astro camera but on the other hand, it is surprisingly efficient and costs pretty much nothing (the camera itself can be bought on MPB for under £100)

Ok so after looking into it in daylight... I forgot somehow to tighten the spider supports. When I shoved the laser in the tube, there has been a "clong" and the red spot was bouncing from the laser, off the secondary and hitting half way through the tube It's actually amazing that I got any image at all. I guess part of the light cone from the primary sneaked onto the secondary and up the tube. I have now very, very carefully aligned everything and collimated as well as is humanely possible and I need to wait for the next hour of clear sky to try... And it's forecast : 100% overcast for as far as the eye can see. To be followed!

Ok, that did not really go as planned 🤣🤣🤣 On a positive note, the mount proved perfectly adequate, with RMS +/-1.00. So... there is that. However the images suffer terrible, terrible abberations, akin to extreme and almost random coma, to the extent that astap was never even able to plate solve. I was able to pass ficus back and forth without ever seeing the bhatinov pattern - that's how bad it was. Image luminous though, 5 secs at uso 800 clearly show the star field. My guess is, combination of poor collimation, focuser sagging and possibly pinched primary. (The thick coat of paint made fitting it in the inner cell a very tight fit,) So... not sure what's next. I am trying to figure out if there is anyway to test the assembly during day time. I guess I need to take it all apart and try to reassemble more precisely.

Yes I know exactly where this is going 😅 I did the maths in reverse actually and the truncated cone by 20mm would result on paper in a primary reduced from the official 203mm to 187mm - which is still PLENTY more than 130. My interrogation on the reality of that comes more from the fact that I suspect strongly that the light cone does not fit exactly the secondary even out of the factory. I suspect it's a tad too small anyway and I have no idea how the CC will do either (it's specifically for newtonians F4>5) I know too well that it is not a perfect solution... But I will not know how much of an improvement (or "de-provement"!) it will be over the 5", considering that other factors are at play : length, weight, momentum etc that can also degrade guiding performance. For starters, my pixel scale goes from 1.83arcsec/px to 1.18. So if my guiding in the same time, due to extra momentum, goes from RMS 0.70 to 1.30, the loss of light cone is really, really the least of my problems! I will know soon enough, nautical dark coming in a couple of hours I will have a shot at M101 which I did a few days ago on the 130PDS so I will have solid comparison data in terms of guiding, exposure length, good sub rate and IQ. And if it is a total fail... Well, It will not be because at the very least I will know a bit more tonight than this morning And I can get back to the 130. And if it works as hoped (hope lives eternal) then I'll gain bragging rights There is no real downside, the Beast was collecting dust in the garage since 2018 anyway...

I installed rods that are 70mm long and in actual facts allow me to place the primary anywhere I want using the collim screws from original position all the way up to +40mm. When I did tests to find the focus point and place the mirror, it ended up 15/18mm above the normal position. As the secondary is quite massive (supposedly full frame coverage) and I am using an APSC I should be ok. But I won't really know before trying, I might end up with terrible vignetting. No idea yet! Let's say I am cautiously optimistic. But because it's in effect an F/4.5 OTA, the cone must be pretty shallow and that could end up getting off the secondary. Again... Only way to know is to try!