Flo94218

Hello everyone! I've just received my new and first ever dedicated astrocamera from SVBONY: The SV405CC. This has a Sony IMX294 Micro four thirds sensor and is fairly similar to any other 294 colour cameras from ZWO, QHY, etc. There are some downsides, like no USB hub on the back and the fan is attached to the back plate with no vibration isolation in mind (4 chunky screws with 4 locknuts mounted on a metal frame which, in turn, attaches to the back pate with 4 M3 screws). I plan on changing the 4 screws for some silicone studs from Noctua or some other brand. That's not a huge downside for me, since I'm shooting through a 450mm setup, so vibrations will be, most likely, sub-pixel, though I am planning to upgrade to an RC in the future. I'll deal with that when I get that. The other thing that's been bugging me has to do with moisture control. First, there's no heating element on the front glass. I believe that's true for ZWO, as well. They claim that the front AR window will be kept above ambient by the heatsink heating up the whole body of the camera. I am not sure how big of an impact this has, since I didn't get the chance to test it out in the field. Probably I'm worrying about nothing. The second problem is that there are no dessicant tablets permanently mounted in the sensor chamber! See... I thought, since there's no info online, that the AR glass is the same size as a 1.25" filter. I wanted to permanently install a IR/UV cut filter in place of the AR glass, so I went ahead and removed the 4 screws holding the AR glass frame and realized that the glass is actually 31mm. So.. I put it back together, warmed up 4 dessicant pellets in the microwave, put them in the screw-in tube and left the tube in for 24 hours. Today, I tested it out with NINA, set the cooling to -5C over 10 minutes. Once the sensor reached 0 degrees, fog started forming on the sensor right away. It went away once I heated the camera (over 10 minutes, as well). Knowing that ZWO has dessicant tablets inside the sensor chamber, I thought it would be a good idea to open up the chamber and refresh those tablets. I've indexed the position of the lid with some masking tape, then unscrewed the 6 2mm hex screws holding down the front plate. Once opened, I realized that there are no dessicant tablets visible anywhere.. I made sure to blow out all the dust with a rocket blower, blew hot, dry air with a hair dryer as I put back the front casing on and, once again, warmed up the 4 dessicant pellets for 5 minutes in the microwave then put them in the tube. I just did that, so I'll be waiting 24 hours and, tomorrow, will refresh them once again and give it another 24 hours. To anyone that has this camera: do you know if there are dessicant tablets below the board, or is the moisture controlled only by the pellets in the tube? Also, to anyone who is looking for a partial teardown of this camera, you're welcome I did get the chance to test it out for 15 minutes before the clouds rolled in (of course). That's 15 minutes, 180s x 5 , 125 gain, 30 offset, -5C, l-eNhance + 8 matching darks. Shot from just outside Bucharest (B8 or 9, I believe), from my balcony, with poor to awful transparency. The bayer matrix for this camera is screwed up.. IMX294 has a RGGB matrix, but the FITS are written as top-down (?), so the matrix ends up as GRBG. Problem is, no Auto debayering works in any software (NINA preview is screwed up, PI can't find the bayer matrix info, SiriL doesn't seem to know how to set the colours even after telling the software that bayer matrix to use. The colours after stacking ended up being yellow. I've attached the starless image that I got out from SiriL. I am not sure if this is because of the filter, or something else. Any idea or advice? I hope I can get some clear skies next weekend, so I can properly test this camera from a B5 zone.

Thanks! Last night, I've moved the tracker's circuit to the Arduino box and attached a much bigger 10k potentiometer with a chicken-head knob, so it's much easier to finely adjust the tracking speed... my thought was that, if I can get the tracking speed as close as I can to the right one, fewer guiding pulses will be needed, which, I guess, it's a good thing. By doing that, I've also removed the big plastic box, so that I get a larger sweep of the telescope before something hits the tracker. I guess there might be a way to flip the whole assembly 180 degrees, so that it points downward, but I can't be bothered to make another bracket for just a few more degrees of movement. Really looking forward to testing it. Sadly, I've only had cloudy nights ever since last Saturday (when I actually took the photo above). More time for diy-ing I guess It would've been really cool if a slewing mod could be implemented, although, with the stock tracking motors, it would have been a veeery slow slew. Also, the DEC screw is stopping anyone from doing a real slew mode on both axes. I will assume that you have removed the big gear for the same reason, correct? I might hack that off as well. As for the photo, thank you! It's not as good as I would've wanted it to be, but I have just discovered that the main mirror was completely coated by a layer of dust and everything was really hazy when looking at it, so I gave it a good cleaning and now I hope it's gonna make a difference. The colours have been tweaked quite alot.. it was more towards a red-ish hue (probably because of the astromod on the camera).

Thank you for the tip! I ended up making a hole straight into that metal piece and taping a screw there. Holds fine, no movement whatsoever. I also thought that the elastic coupler would work fine against the in/out issue, but hearing someone that has been using it for a while puts my mind at ease. I will try looking into sharpcap for polar alignment, the one in PHD2 is kinda unintuitive for me... never used that software before. I used the same 9V for the DEC motor as well, I hope it won't be too powerful and send it over shooting, but I think phd2 knows how to deal with that. I am currently using a camera lens stuck at 50mm and a generic Webcam 1/2.7". It sees the stars pretty well, but I might need to get a longer focal length guide scope.. I am imaging with a 130/920 omegon reflector and a Canon 1100D and that 50mm is waaaaay too small, I think it's best that the guide scope is 1 third of the main scope's focal length.. I am not sure if the crop factor applies in the equation as well or not. I managed to get a pretty good shot of M42, 8x30sec 1600ISO using RA guiding only with really crappy polar alignment, but I think it came out really great for a 300 euro setup lol.

Hey there! I know this is a long dead thread, but here goes nothing. Let me start by saying thank you! I, too, was struggling with inconsistent tracking when using the EQ2 motor and this autoguiding project was a true life saver. I managed to adapt your project and make it work with an Arduino and PHD2 (through some custom ASCOM drivers written by someone) with the RA motor only. It works really well, even for exposures of 2 minutes, but the DEC drift starts to show up... I can't really do a very good polar alignment, given the EQ2s' lack of fine AZ control and lack of a polar scope. PHD2 polar drift is somewhat successful, but it's still not perfect. So... I went ahead and ordered a second Motor for the DEC axis as well and I am in the process of mounting it on the scope, but I'm wondering how you have attached the motor to the mount.. The bracket that comes with the motor doesn't really go anywhere on the mount. Also, did you have any trouble with the fact that the DEC adjustment screws in and out? I know the adjustment will be very fine, but I was wondering if at some point it gets too far in/out and starts bending the motor. Any help will be greatly appreciated! Thank you!