symmetal

Your wiring colours are correct and are what I've used for several skywatcher mounts including the AZEQ6. In serial comms the TXD of one device connects to the RXD of the other device and vice-versa so the AZEQ6 manual is compatible with your wiring. 🙂 You're fine using 5V TTL232R as the 3.3V interfaces currently used work with 5V without problems. Not all mounts are 3.3V though it seems to be more common now. My new EQ8-R is still 5V though. Alan

@Fegato @Elp Thanks, I'll go for the Aurora one. After spending so much on scope and camera skimping on a minor item probably isn't worth it. 🙂 I do have a rigid dewshield that I 3D printed in three parts. I've flocked the inside now as well. I thought it might be too long at 400mm causing some vignetting, buts the flats are no different with or without it. It's a bit heavy though so I may try again using 1mm thickness for most of the tube with a couple of thicker ring sections for rigidity. I'll make it a bit shorter too, as at the moment, it just fits through the roll-off shed doorway at one specific position. The Ender 5 Plus is just big enough to print it. The 4 spigots slide in the dovetail ends, so it is at the same position all the time. The bulge at the top rear allows the cables to pass through. 🙂 Alan

I calibrated with two flats, one as before and one with the Huion panel rotated 180. They are very different so the panel looks to be the culprit. As the panel is stood vertically against the dew shield they are not looking at the same panel area, hence not looking similar, but just rotated. I see that EL panels are cheaper on ebay compared to the Aurora ones. Aurora 315mm circular panel with mains inverter is £249 from Widescreen Centre, while an A2 panel from ebay with mains inverter is £160. Is it worth going for the cheaper one, or do you think the Aurora ones are selected for more even illumination? @Fegato Thanks for the extra info. I used 3 sheets of 0.9ND filter on the light panel totaling 9 stops which allowed 0.5s flats exposure, but they were similar to the results with no ND filter and 0.5mS exposures. I think the earlier CMOS cameras had issues with short exposures, compared to the newer ones. I agree that it's not worth rotating the camera. Luckily, if I remove the camera and put it back in the same orientation even if having to loosen off the Celestron adapter plate to position it accurately, it does give the same results each time which is good. So adding thin spacers to get the right star shapes for the 2600 shouldn't be a problem, I hope. Alan

@Fegato Thanks for your information about your RASA11. Most helpful. I thought the Celestron M48 fitting would lead to full-frame vignetting. I'll take a look at the Baader UFC system. If my flat frames worked I wouldn't have been too worried. My A4 Huion panel was fine with the RASA8 but the A2 one may not have such even illumination. I'll try it rotated 180 degrees and see if the flats problem rotates with it. I'll get an Aurora or similar if that's the case. I was surprised that the 6200 gave good stars on first try while the 2600 didn't. It looks like the spacing needs to be within 0.1mm or so. My current smallest spacer is 0.3mm but that causes issues in the other direction if used. I found the filter drawer on the 6200 ended up under my cable routing so I thought I'd just rotate the camera 180 degrees. Not good as poor corner stars resulted. Put it back again and all good so I've had to change the cable routing. Looks like the good stars was mainly luck. I assume you use the HCG mode on at gain 140 for your camera. I may try 0 gain for luminance as I mentioned above just to avoid spending more time downloading than imaging. 🙂 You have a great collection of images on your site. 😀 Alan

The RASA does seem very stable optical wise. I was concerned that mirror flop might give focus/tilt problems like the first RASA 11 version, after a flip, but that has been fixed with the V2. All corner stars still round and in focus, a re-focus ending up in the same position after a flip. Unlike the V1 there are also no mirror locks on the V2 as they aren't needed which is great. There is a slight image shift when the focuser changes direction of about 10 pixels but the focus itself doesn't appear to be affected. Yes, you're right Göran, the gain is applied either at the camera or later in processing. Apart from increased read noise at gain 0, but that gets swamped pretty quickly anyway so won't really be an issue, particularly if I bin 2x2 in the camera. Thanks for your processing showing the IFN like @ONIKKINEN has done too. Must improve my processing. 😁 Alan

That's a good point. The 6200 download times are twice that of the 2600. The image I posted was reduced to 50% in PS anyway to make it look 'better' so I could do it in the camera and speed things up. PS uses bilinear interpretation rather than just combining pixels so that may make a noticeable difference. There are a few green hours on some days expected this week although the Moon is full. I can do comparison tests on different gains and binning though. 🙂 Alan

@wimvb Oops, I forgot you have already imaged this galaxy, and I commented too. . Your colour image seems to make it easier to pick out the fainter stars. Where did you get the information detailing the invidual known stars?. Here's the stack without flat calibration. There's 380 ADU difference between the centre and the corners. Ursa Major I no flats.fits If you crop it to APS-C size I suppose the vignetting isn't too bad. Using gain 0 I'd lose the HCG lower read noise, though with long enough exposures that won't matter. Gain 0 is also still higher than unity gain so you don't throw away any photons. It's worth considering for luminance at least. Thanks. Alan

@ONIKKINEN Wow, thanks for processing that and showing the IFN. I was using Startools which I think has trouble stretching without a feature to focus on as it ends up stretching the noise. I'll have to try something else. I have AstroArt 8 and APP as well as PS. I used to use AA mainly for calibration but use APP now although it does take much longer to calibrate. I'm restacking now without flat calibration which might be easier to fix as the vignetting looks a standard shape falloff. I'm wondering as to whether the flats illumination is reflecting off the shiny red rim of the camera causing the bright ring that dominates the flat calib version. I'll try 3D printing a black cover to fit over the camera to hopefully improve that. PLA+ isn't available in matt finish, only PLA, which is too weak to work with, so I'll have to spray paint the PLA+ gloss version. I'll post the no flat calibration version when it's done which you may have more success with. I was feeling quite dejected with the poor result I got for all that expense, but you have shown that it gives good results if you process it properly. 😊 Bright stars near the edge of full frame are a bit flarey, but not like the horrible asymmetric flares I was getting all over with the RASA 8. Alan

M48 Spacer set at £17.09. They also do a M54 Spacer set at £19.29, free shipping to UK. Actually there are 9 in the set with 0.15mm included and no 0.7 or 0.9mm which is better. I had previously ordered an M54 adapter from them which wasn't available in the UK, and was impressed with the service. Shipped the same day, and they keep you very up to date with emails on its shipping progress and it only took 10 days with free shipping. Alan

First time last week to use the new RASA 11 for an extended period. Thought I'd try the ASI6200MM full frame camera with a luminance filter for deep sky hunting. Very happy with the star shapes out to the corners though the vignetting is quite severe. I think the 48mm adapter on the RASA 11, the largest one supplied, is a bit restrictive for full frame. Unable to get good flats despite several methods which all produced different results, none of which worked properly. On one occasion I forgot the A2 Huion flat panel was on top the scope and moved it to the home position. Panel lands on concrete, corner first which took a chunk out of the perspex and a crack across the panel face. 😬 Panel still working though and the crack is outside the viewed area. I thought I'd try for Ursa Major I Dwarf, apparantly the third dimmest galaxy known. According to McConnachie's Properties of Dwarf Galaxies in the Local Group (2012) it has an apparent magnitude of 14.4 and a radius containing half the galaxy's light of 11.3 arcmin. The mean surface brightness within this area is 28.8 mag/arcsec^2. Here's around 3.5 hours of 60 sec exposures with no moon and I was disappointed with the result. Not even any IFN. Annotation checks showed nothing but a couple of galaxies near the edge. Must be a contender for the most boring picture ever. I've marked approximately where the galaxy should be. I've uploaded the APP stack here if anyone wants a go at revealing anything. You'll have to deal with the odd gradients though due to poor flat calibration. It's 240MB big. No visual images of the galaxy exist AFAIK not even from Hubble. At the moment that's still true. 😊 Ursa Major I Lum.fits The SQM reading was 21.4 and I was swamping the read noise by 5 by the sky background noise at around 10s exposure but I'd be wasting over half the imaging time just downloading and get TB of data, so used 60s as a compromise accepting all the blown brighter stars. I did start with a couple of hours on NGC147 to see if I could resolve the star streams that @wimvb was looking for, but the Moon was too close to show anything. The ASI2600MC is showing rather misshapen stars due to the spacing not being correct. I've ordered a set of 10 M48 stainless steel spacing rings from 0.1mm to 1mm via AliExpress which should be here soon. Spacing is very critical. Alan

Another gem Göran. 😊 With the depth of detail the LBN and LDN designated areas seem rather randomly splashed about. 😁 Alan

I have one of the m48 CTU. Both sides are female M48 so use adapters as necessary. As well as having the adjustment screws on the rim there are just three of them rather than 3 pairs of push pull screws like cheaper units. A strong spring inside the CTU trying to keep the plates together, takes the place of the three pull screws. The three rim screws push the plates apart and are finely threaded so you have more precise adjustment. Alan

They work at any elevation though must be adjusted to match the elevation. The lower in the sky the more dispersion occurs but is still significant at higher elevations as shown by this graph. Alan

Glad that's fixed it. 🤗 For info you can set the heap size on the Firecapture settings 'General' tab. This is the amount of RAM the program can use. I always have the RAM buffer setting enabled too as it gives a nice readout of the frame buffer and how many frames are available during capture. I think on later versions of Firecapture the RAM buffer automatically follows the heap size, so doesn't need to be set separately. With RAM buffer enabled it nees to be recalculated when you change the capture ROI which takes a few seconds. Alan

Click 'More', but not on the arrow on the right. This gives you camera settings where you can set High Speed and USB Traffic. For a small ROI you can normally set the USB Traffic to 100% with no problems. If you start losing frames or get no picture turn it down a bit. Alan

Great images Mariusz. You're lucky having some spectacular dwarf galaxies visible in the Southern Hemisphere. 😃 You need to be quick to image it though as it'll merge with the Milky Way in a few billion years and lose its identity. 😛 Alan

Very impressive Göran. There is more of interest and colour in the dust than the 'little' galaxy, in the more wide field view. 😊 Alan

Have you tried selecting 'High Speed' mode in Firecapture's camera setup. This uses a lower ADC conversion bit depth like 9 or 10 bits so gives a faster fps. As 8 bit mode is usually used in planetary this is fine. I assume you have 8-bit mode selected, as 16-bit will usually halve your frame rate. Also don't have gamma enabled, or leave it at 50 which is the same as disabled. Disabling preview debayering may give a few more fps on a lower spec computer. Allocate around half your RAM to Firecapture's heap space on it's setup options. The first few seconds of capture are stored in RAM buffer and when full, starts writing to disk. If your frame rate drops only after the buffer space reaches near zero this means it's the slow disk writes causing your fps drop. Alan

Amazing result for Bortle 8. 😃 Alan

Spectacular Aeroket. Perfect framing too. Oh! and welcome to the forum 😊 Alan

No problem Andy. The vibration frequency is too high and amplitude too small to have any effect on the mount but feel free to check. 🙂 Alan

No it won't, unless it gets loud and you can feel the vibration which I can't see happening. Many power supplies in particular make a noise, linear ones can buzz or hum, and switch mode supplies can give of a high pitch whine. This is due to the continuously changing magnetic fields in inductors or transformers which are carrying significant currents creating a force which tries to make them vibrate very slightly, (Fleming's Left Hand Rule). They continue working for years without problems. 😉 Here's an article explaining acoustic noise in switched-mode power supplies. Half way down it mentions the piezo effect which is likely the cause in your case. It states that "Ceramic capacitors that undergo high dv/dt swings often prove to be audibly noisy" High dv/dt means a large voltage swing in a short period of time, which is what's happening in your dew controller PWM circuitry. If the noise isn't too much of a bother then I should leave it as it is. 🙂 Alan

By default Firecapture will always capture in raw (not debayered) but will preview in colour (if a colour camera is used). If you click on the arrow next to the debayer icon you can choose to not debayer in preview, and also the option to force debayering during capture, though it strongly recommends that you don't allow this, as it sevely restricts your fps rate. Alan

This is a common side effect of PWM (pulse width monulation) switching used to control the dew strap power, as a result of the circuit design and possible PCB board layout. At 0% and 100% there is no actual PWM switching occuring so there is no noise generated. PWM is used as it's very power efficient and easy to implement. The noise is generally produced by capacitors on the PWM output circuitry, commonly ceramic plate, among others, the plates of which will vibrate at the switching frequency due to the piezoelectric effect. As surface mount capacitors are usually used nowadays, this plate vibration gets transmitted to the PCB itself and it's the PCB vibrating you can hear. The MOSFET (Metal Oxide Semiconductor Field Effect Transistors) commonly used for the power switching can switch very fast and unless steps are taken to limit the rate at which the voltage changes on the MOSFET gate pin then it's likely the switching output will be too fast and 'ring' after each transition which is a high frequency AC voltage oscillation which decays over time, superimposed on the PWM waveform. This will likely make the audible noise louder, as well as reduce the switching efficiency, making the MOSFETs run hotter than they should. I made my own Arduino based PWM dew controllers which switch at 4kHz or 8kHz depending on the output used, and using an oscilloscope to check the output waveform, selected components to eliminate any 'ringing' while still switching at a fast enough speed, and also used through hole components rather than surface mount, so any possible vibrating components are mechanically isolated from the PCB. It's totally silent as a result. 🙂 Changing the PWM switching speed in software could make the noise less annoying, or clamping the PCB down more to reduce vibrations. Putting a small resistor capacitor combination in parallel with the dew strap would likely inhibit the ringing, but the capacitor mustn't be too large that it stops the FET switching fast enough which could cause it to overheat. Probably more than you wanted to know. 😊 Alan

I unfortunately missed this one when it was first posted so a belated Wow Wim. 😊 Your patience paid off. Alan