symmetal

According to the Orion Dynamo Pro user manual they are 2.1mm DC outlets, with standard 5.5mm outside diameter so it's odd why your cables don't fit well. If they are hard to push in to connect why do they then easily fall out? You can use the three-way cigarette lighter adapter but it's best to have the minimum number of connectors in series to give good reliability and some cigarette lighter sockets can disconnect too easily, depending on the friction available as the plugs are inserted. Alan

In SGP select the Menu item 'Help/View Log' and it should tell you what it's been doing and the messages it's received and the date and time they happened. Hopefully it will indicate why it has stopped and what it's waiting for. You can view the log files if SGP is not running by looking in C:\Users\[USERNAME]\AppData\Local\SequenceGenerator\ Alan

The moons orbital plane is at an angle compared to the Earth's equatorial plane so will slowly move 1 cycle up and down in declination taking approximately 1 Earth day to complete, if viewed using an equatorial mount. In the diagram below the moon's orbital plane is inclined 23.44 + 5.14 = 28.58 degrees to the Earth's equatorial plane, which your eq mount is aligned to. This periodic declination cycle won't be exactly 1 Earth day long as the Moon also orbits the Earth every 28 days or so. 🙂 Alan

Here's another one I managed to get last week. FLT98 + 0.8 reducer and Atik One 6.0 CCD. 16 x 10 min each of RGB and 32 x 5 min of L. Stacked in Astroart, processed with Startools and final tweaks with PS. Click for full size. It seems I just managed to catch a peek of NGC5198 elliptical galaxy at the bottom centre too. 😀 Alan

Great combination image with plenty of detail on M45. 🙂 Alan

I removed the filter wheel from my Atik One and found this on the red filter which I hope is the cause of the diffraction spikes on just the red. There was also a film over most of the red filter which wasn't present on the others which may help to explain the pattern, again only on red, around the highly clipped stars similar to what you get to a larger extent with dew. Now cleaning it, so fingers crossed it'll improve it. 😀 I've tried the latest beta version of Startools which was has many changes and several extra features over the standard stable release. One of these is 'Highlight Repair' on the 'Colour' module which is to remove coloured fringing around saturated stars. This worked very well on the smaller clipped stars basically desaturating the star edges but the above star was beyond help in that respect. The Startools site forum has several links to instructional videos which may be useful. The manual is a bit out of date and incomplete but in the program clicking the help button on each module gives a web page of an explanation of what it does. Each adjustable parameter on each module has an '?' button which gives helpful info on what it does too. Alan

Thanks Mick. Startools is very good for maintaining star colour as all processing steps are done on linear data but I seem to end up with stars of multiple colours for very clipped stars. I normally use the automatically generated masks in Startools but it might be worth manually modifying them to control their processing. It's probably easiest just doing a simple stretch in PS to get the best clipped stars and layering them over the Startools image. Alan

I don't think you'll be using as much current as that in reality Adam. Dew heaters will be around 1A at full power unless you have a large scope. The mount will consume more when slewing. My dual rig with cameras cooled, plus guide scope, 3 dew heaters via controllers, AZEQ6, mini PC, USB hub, dual auto focusers, consumes about 4.5A in total when tracking/imaging and around 6.5A when slewing in both axis. It all runs from a 100W switch mode which can supply 8.5A. It just runs warm in use. Having extra capacity is always a good thing so the 30A PSU will just be coasting. 😀 Alan

I use switch-mode supplies for all my gear and haven't had any issues with them. Switch-mode supplies generally have more high frequency noise on their output than linear ones though I've found that doesn't cause any issues with astro cameras. I did comparison tests on my Atik CCD running off a switch mode and a leisure battery and there was no difference in the noise output from the camera. As virtually all CMOS cameras are powered from much more noisy USB anyway that isn't an issue. I have the PSW-30H you linked to as a general purpose supply. I also have the Nevada 8A linear and used it for a while but it gets hot even supplying 4A so needs good ventilation. Also on mine the ammeter reading is just a suggestion and reads 2A more than it's actually supplying. FLO actually sell the Nevada PSW-30 switch-mode as well which is much the same model as the PSW-30H but in a more stylish case and also has variable output voltage too. Alan

During the clear spell last week I managed to get 10 hrs worth of data on M81 and 82 using an FLT98 + 0.8 reducer and Atik One 6.0 CCD. 16 x 10 min each of RGB and 28 x 5 min of L. Stacked in Astroart, registered with Registar and processed with Startools and PS. I was wondering whether I could see the dust lanes as seen in other images and while they were visible they were noisy so I've just shown a hint of them and used Olly's trick of flattening the PS curve just below the level of the dust to remove a lot of the noise. 😀 The very bright stars tended to be composed of coloured rings so I blurred the centre of those stars as a separate layer in PS and substituted mono versions of the stars on another layer of those that were beyond help. The two bright stars bottom left also had two very noticible diffraction spikes on just the red channel so there may be a hair on the filter or something. I've hidden the spikes reasonably well. Just to the left of M81 there is a smudge which is actually Holmberg IX, a dwarf irregular galaxy of magnitude 16.5 and is a satellite galaxy of M81. This is on my dual rig with the other one being an ASI 1600 and a ZS61 so I have the same amount of data on that minus those spoiled by dithering the Atik images. While it's a significantly shorter focal length the smaller pixel size means the difference in imaging scale is not that great. I'll process that later to see how the CMOS camera compares to the CCD. 😀 Alan

I had a similar problem in the past and I believe it was an error in the starsConfig.json file in your local Stellarium folder possibly with a checksum entry. Try copying the contents of your C:\Users\[USERNAME]\AppData\Roaming\|Stellarium\stars\default\ folder from your laptop to your home PC including the .json file and restarting Stellarium. I believe that fixed my problem. 🙂 Alan

Great image and write-up along with it. I took images of Abell 1656 Coma Cluster over the last few days using an ASI071 OSC APS-C sensor and 360mm ZS61 scope just to see what comes out as there weren't any suitable wide field OSC targets around at the time. It looks promising with a quick process but I don't think it'll match yours. 😀 Alan

Yes, that's correct. You normally need to use darks with CMOS cameras due to so called 'amp glow' anyway and the darks include the bias signal so that takes care of it. That's interesting vlaiv. I've just used around 2 second or so exposures for flats, and flat darks for all CMOS cameras to save having to be concerned with the issue. 😀 Alan

It seems that many CMOS cameras have different modes of operation between short (less than around 1 second or so), and long exposures as detailed in this thread here CMOS Bias Stability where short exposures have internal bias calibration applied, while long exposures don't. So flats and flat darks of short duration won't accurately match your longer lights exposures when calibrating. Longer exposure darks and dark flats avoids this issue hence the recommendations to use flats of a few seconds duration at least. CCD cameras dont have this issue so short duration flats and using bias as flat darks is fine for them. Alan

Impressive detail there. I'm happy just getting some detail of sorts on Jupiter itself. My moons are always just tiny white blobs. Alan

I have to admit I was wrong when I said APT only uses Ascom drivers. It's been a while since I used it. If you choose the Zwo camera from the APT camera selector you are using the native driver. Choosing Ascom, then the Zwo camera, uses the Ascom driver. So yours works OK when using the Ascom driver. Using the native driver the 'settings' button gives you access to 'offset' and 'USB Speed' I'm not sure what the USB speed figure is it's looking for, but is possibly a percentage like you see in the Ascom driver settings where it can be set between 40 and 100%. Its default setting is the slowest at 40%. On checking mine it's blank in the native driver USB speed setting, which may default to 100%. Try putting the figure as displayed in the Ascom driver and see if that works. Depending on your hardware and cable lengths/quality it may not work properly if set to 100% and may hang or display a blank screen when downloading images. Alan

It might be worth re-installing the latest Zwo Ascom driver, which is listed below the native driver on the page. Sharpcap allows you to select the 'Zwo ASI120MC' camera which is using the Zwo native driver or the 'ASI Camera (1)' which is using the Zwo Ascom driver. You probably selected 'Zwo ASI120MC' in Sharpcap which is why it worked OK. APT only allows you to use Ascom drivers if you're not using a DSLR which may be the reason for your problem in APT. Alan

Glad it's working Notty. Just curious, your initial post said you were using APT, hence my and Thalestris24's replies, but your last post said you were using SGP. SGP does allow native Zwo drivers to be used so the offset is available to be set in SGP should you wish. If you choose the Ascom driver then it's not as I mentioned above. Alan

SGP doesn't do any debayering, even for previews so your preview image will be grey with the bayer grid visible if you zoom in. Your stacking program will do the debayering. The readout noise parameter setting is optional and is only used in calculating the theoretical ideal exposure time displayed in the image statistics panel. It has no other function. Alan

It looks like APT only allows the Ascom driver settings to be changed when the camera is disconnected. If the camera is connected click the 'Settings' button at the bottom right of the camera tab. This will temporarily disconnect the camera to allow the Ascom settings to be changed. If the camera is already disconnected hold 'Shift' while clicking the camera 'Connect' button and the CCD Ascom camera option is selected. Click OK and select your camera in the Ascom select box and then click 'Properties' to set the driver options. In either case this dialog box should appear. You need 'Advanced' ticked in order to see the see the Offset and USB Limit setting. Offset is not available to be set outside of the Ascom driver as due to a limitation of the current Ascom implementation, that parameter is not accessible to the parent program (APT). If the ZWO native driver was able to be used in APT, then the offset could then be set in APT. However it only seems to use Ascom drivers only. Alan

Hi Adrian, That would rate about a 4 on your scale. It's pretty good. CCDI assumes higher fwhm figures are due to focus errors and gives tilt and curvature figures on this basis. However using standard lenses there could be other effects like coma giving a higher fwhm figure so it's better to check the star shapes in the corners to assess the reason for the higher figures before you blame it on tilt or curvature. Dark blue indicates lowest fwhm (assumed best focus) while medium blue is still very good. Ligher blue it's worse but not too bad. When it starts going pink is where you need to check what the problem is and whether anything can be done. The 3D curvature plot (Ctrl-3 I think) can give a more useful indication but as I mention below CCDI may interpret tilt as curvature so take it just as an indication and not fact. If you take similar images using LRG or B filters you will probably get quite a variation in CCDI results too so need to see if there is a common 'error' on them all which could indicate a tilt error. On your Ha image it's only very slight (assuming it is due to focus) but it could be worse on blue at the other end of the spectrum. CCDI doesn't know if an out of focus star is in front or behind the plane of focus so a progressive worsening of focus across the image is assumed to be tilt while focus that is better in the centre is assumed to be curvature, though it could still be tilt with stars on one side in front of the focal plane while thouse on the other side are behind. As for collimation error I'm not sure what method CCDI uses to calculate it for refractors, or whether it really means anything. I did ask here some time ago what this actually indicated but no-one had an answer at the time. I've generally found that just looking at the star shapes across the image gives a better assessment than just using the CCDI figures. CCDI assumes all errors are due to focus which in many cases is not the full story. Alan

Glad it helped John. If you go to a major distribution company like Farnell and display 10uF 16V SMD Tantalum Capacitors, you get a choice of 244 entries. Scroll down to find one that looks similar, and click on the pdf link under the order code. This will give you all the info on that series of capacitors from the manufacturer including dimensions. When you've found one that fits either buy it from Farnell or RS etc. or look for the same item on ebay etc. Alan

Hello John, Yes 106C markings means 10μF and 16V working. If the μ symbol isn't printed and the third digit is 5 or above, then it's a fairly safe bet the value is in picoFarads (pF) with the third digit being the multiplier. So 106 means 10,000,000 pF = 10μF. The voltage is indicated by the letter after the three digit number as indicated in the table in the third picture below. As you can see from the first image it takes deduction and some have their own markings. Metal can types have the value in μF without the symbol while the 7th to 9th ones on the first image would appear to be in μF as well. For polarity the non-metal can types have a bar to indicate the positive end. Note that for the metal can types the black banded end is the negative. It looks like some have a champhered end as well as a bar to indicate the positive. Alan

I would have expected better from a Canon 'L' zoom from what yours shows. I have a Canon 100-400 L zoom and it has noticeable coma too but not as bad as yours. I've not had much luck using lenses for astro. Even my Samyang 14mm which is widely regarded as giving good astro images has bad coma like aberration over the whole frame, even when stopped down. The only lens I have which doesn't show noticeable coma is a Canon 40mm 'pancake' lens. Alan

This is a problem primarily with coma caused by the lens itself, and is visible in varying degrees when using normal photographic lenses for astrophotography. The lenses were not designed with astrophotography in mind and controlling the coma of point light sources off axis is not a high priority, particularly in lower cost lenses. Zoom lenses, having more elements than prime lenses are more likely to show more coma too. The lenses not being perfectly centred on the optical axis can also cause this effect so two lenses of the same type may exhibit different coma characteristics depending on how well they were aligned in manufacture. This is probably why your image shows it worse at the top. There are a number of lenses mentioned in various topics here that are noted as having very good coma characteristics, though some people have had to send the lens back to have it swapped for another, to find one that is good. The only way to reduce the lens coma shown is to reduce the lens aperture, by stopping the lens down by a stop or two. This reduces the maximum angle of off axis light rays. This does mean longer exposures to compensate so is not always a practical solution. Alan