michael8554

It's funny how the brain sees patterns in random noise, to my mind there are 5 or 6 bunnies in your image! Show us one of your flats, stretched, that would be revealing. Even better, if you're sure it's the camera, make a flat with nothing attached. Michael

Classic low voltage behaviour. Try your power tank which will be more like 13v, or a 3Amp mains powered brick. Michael

Perhaps I'm missing something here? The only way to be sure that you're focused on infinity is if you're able to pass through best focus, and then reverse back to best focus? Michael

You're not going to solve this without giving us useful information, this tells us nothing. Did the mount move towards Altair, or away, where did it end up, etc etc? Michael

Agreed Alan, which is why I was surprised that research suggested otherwise. But peeb hasn't said yet whether it's all corners or just one. Still looks like coma to me though... Michael

What is "It" that is seeing the moon etc? Michael

I agree with Peter, don't use Polaris as an alignment star. Are you correctly following the procedure in the User Manual? There are usually times when you centre with the handset, and times when you release the clutches and centre, don't mix them up. Michael

So does the mount go to the first star without much error? If it goes to completely wrong position then initial setup position may be wrong. Have you read the User Manual? Could be wrong but I thought you started with the scope tube horizontal and pointing north, not up to Polaris? Michael

Wow, that's different! Did Venci give any explanation of what he had done? Michael

Interesting - I don't have one so searched for this, the articles I saw said they suffered from Coma! Looks like Coma, quacks like Coma......... 🙂 Michael

Not clear from your post, is the distortion in all 4 corners? Then yes it's Coma. Either crop your results or fit a Coma Corrector. Michael

Try screwing in without the knob to see how far the thread goes, then you know the longest screw that will fit if you can't get the right length. Michael

Unscrew one of the remaining screws and measure it.!! Then go to Wilkinsons, Robert Dyas, or any DIY supermarket. Looks like it has a countersunk head. Measure the length of the threaded section. If you're lucky it's metric, then the diameter of the threaded section indicates its description eg 6mm means it's M6. So you'll need an eg 15mm long M6 Countersunk head screw. Michael

It's not clear to me whether you are manually or auto focusing? I've not imaged with a lens but would think that accurate autofocusing on stars is challenging for the camera? I've read here of successful manual focusing using a bright star to start with, then dimmer and dimmer ones. Michael

First of all read and apply these guidelines: https://openphdguiding.org/phd2-best-practices/ Your RA and Dec Guiderates are 0.10x of sidereal, way too low, try 0.80x as you have Dec Backlash. Before Calibration, Manual Guide the mount North with the step size set to 5000, otherwise you won't discern any movement. Guide Assistant reports PA error in arcmins, and 5 arcmins would be a figure to aim for. So did it really report an error of nearly 60 arcmins? Michael

I guess you mean a Bolt, and the flats have rounded ? Molegrip if you're lucky. Or make a screwdriver slot with a hacksaw. Michael

Polar Alignment gets the mount's RA axis accurately pointing at the North Celestial Pole, so that the mount tracks stars as they move across the sky. At this point the mount has a rough idea where it's pointing at any moment, based on date, time, location. So the Star Alignment gives it two or three accurate star positions to fine-tune its sky map. Plate Solving tells you the RA and Dec of an image from your imaging camera, and as Dave said some software will then slew the scope to where you intended the scope to point. But again as Dave said, if you're just going to image one target, skip the Star Alignment and Plate Solving. Goto and sync on a star near the target, that will fine-tune the mount's sky map to an area around the star, so a subsequent goto your target should be in the camera's frame. Normally planets are imaged by shooting a very high frame-rate movie. Then software discards blurred frames and aligns and stacks the rest into a single still, so guiding isn't necessary. Michael

Small guidescope with f2 imaging scope should work. Small guidescope and f10 imaging scope - no Michael

As nobody with Synscan experience has answered, my best guess is: Enter Longitude first, 28 34E Then Latitude, 43 49N Date is american format, mm/dd/yyyy Time is GMT +3 as you say, with DST on. Looks like the scope has to be on the left of the mount and pointing north and level to start with. Michael

Very early Canon DSLR's (300D, 350D, 400D and 20D, 20Da, 30D, 5D) only download via the USB, you have to use a serial cable to the shutter socket to get over 30 sec exposures. All others except the M series Mirrorless cameras have full control over the USB. Read the Gary Honis instructions: http://dslrmodifications.com/rebelmod450d1.html Michael

That's a rather misleading reply. Yes, a Canon M would be great for long exposure imaging. Trouble is, AFAIK you can't tether it to a PC to take exposures longer than 30 secs, or to focus using a decent size screen. Back Yard EOS and APT don't list any M camera as compatible. So Intervalometer and save to SD card. I'm not sure if Full Spectrum plus a Clip-In filter is any improvement on just taking out the Ha robbing filter and leaving the IR filter in place to protect the sensor and to retain Sensor Cleaning. Michael

If you're going to modify a Canon, and are attaching to a scope so not bothered about loss of autofocus, then you remove one filter and retain the IR cut filter. Canon 450D has LiveView and is about the cheapest camera suitable for imaging. 600D has an articulated screen which saves backache on some scopes. 700D and newer can suffer from "banding" on long exposures due to the positioning of lines of AF sensors in the imaging chip. Michael

If this is regarding the Canon 10D in your equipment list, simply take flats with the AV setting. Michael

There's probably an optimum ratio but no idea what it is. Too much and you could be stacking hot pixels. Your image has loads of stars, another object may have far fewer, so depends. Michael

The corners look fine to me in all but the last one, given the combination of gear you used. What star threshold did you use ( how many stars used?) Dither should be 12 or so pixels for a DSLR. Michael