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don4l

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don4l last won the day on December 30 2019

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About don4l

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  1. I missed that question earlier, so here goes... That's the really hard bit. Each frame is in it's own layer and I adjust the contrast and brightness until they almost match. Then I use gradients on the adjustments to apply them with different strengths across the frame. This works most of the time. When I can still see some of the joins I then delete "splodges" of the upper layer so that the offending difference is no longer a straight line. I've done that twice in this image. When it isn't a straight line it becomes very difficult to see.
  2. On my first attempt at this, in 2018, I just moved the camera sideways until the right side of the frame was where the left side had been for the previous frame. This was the result:- I not a mathematician, and I spent ages trying to figure out the effects of photographing the inside of a sphere. In the end I decided that the answer was much simpler. The camera is on a polar mount, and the whole thing rotates as you move East or West. As you get nearer the Pole, the effect increases. To fix the problem, I didn't resort to any fancy maths. I have a two stage system. I platesolve the first image and display it in Cartes du Ciel. (This bit takes a bit of learning). Then, when I am lining up the next frame, I take a test image and platesolve it. CCDCiel (My imaging SW) can then display the frame in Cartes du Ciel:- The red box is CdC's "CCD finder rectangle". It has been placed in that position be CCDCiel's platesolver. I can see that I need to rotate the camera a bit anti-clockwise before I take another short sub to platesolve again. When the red box is lined up exactly as I want, I am ready to carry on. This usually takes 2-3 minutes. The tricky bit is learning to process images so that they can be displayed in CdC. They need to be platesolved FITS images, scaled for 0 - 65000 (16 bit) or 0-255 (8 bit). Here is one to play with if anybody wants to try. Just put it into CdC's pictures directory, and choose "Setup -> Pictures -> Image Archive" and go to the Elephant's Trunk. CepB2.fit
  3. My limited experience is that over sampling won't make the stars bigger. However, I spent last Spring imaging at 2000mm with 6nm pixels, which I think was 0.6" per pixel. After a few images I changed to 2 x 2 binning and the only difference that I could see was smaller file sizes and quicker processing times. There was no noticeable difference in star size, and to be fair, they really aren't as "pin-point" as images taken at a shorter F/L. You've hinted at tracking problems. I suspect that this might be an issue. If you have PHD2, then what sort of RMS" do you get? Some nights I have 0.6, and other nights it can be about 1". The difference in the star sizes is noticeable.
  4. Click on image for full resolution. After spending years trying to capture a mosaic of Cygnus, I've now managed to do a similar job on Cepheus in 6 weeks, which is very pleasing. I've still not managed to grab all the frames first time around, because I underestimated the amount of exposure that each frame would need, so I had to do some of it twice. I did have a quick go at this a couple of years ago, but I really didn't understand the fact that the camera would need to be rotated for each East or West movement. (I'll show the non-rotated result below the main image) This is 12 panels. On average, each panel has 10 x 5m exposures, through a 3nm Ha filter. Total about 10 hours. The camera is a G3 16200 on a FSQ106 at 387mm. The field of view is about 11 x 11 degrees. There are lots of Sharpless objects in Cepheus. The next image is a screenshot from Cartes du Ciel which shows them. Each frame was calibrated and stacked in CCDStack. Everything else was done in Affinity apart from the cropping and scaling of the CdC screenshot. Affinity uses non-destructive editing. This means that I can easily go back and make adjustments. So, if anybody wants to make suggestions for improvements, please feel free. Thanks for looking.
  5. I got myself a Pi a couple of years ago. It wasn't up to the job of running my kit at the pier, but it did serve to get me used to the idea of Linux. I bought a cheap refurbished Dell laptop for £280.00 and I haven't looked back since. I am running Ubuntu 16.04 on the laptop and it has been absolutely flawless. The only real problem that I had with the Pi was the speed of transferring the image files. It really was painful. I'm using Indi, CCDCiel, Cartes du Ciel, ASTAP and PHD2 on the Linux laptop. I use VNC to access it from indoors. Finally, I am using SAMBA to map the laptop's image directory to my imaging PC. I just drag and drop the files across. It all works on WiFi. CCDCiel is greatly underrated in my opinion.
  6. Superb image. Very nicely processed.
  7. don4l

    Aliexpress

    I haven't bought anything from them, but it is probably worth mentioning a couple of things about duty and VAT that often catch people out. The duty is calculated on the landed cost. ie, the invoice value plus the carriage costs. The VAT is then calculated on the (Invoice+Carriage + duty). This is the bit that catches most people out. However, when you buy something in a shop, the VAT is on the entire sales price. The shopkeeper will have included all costs, including shipping, before he calculates the VAT. Duty on many items is at zero% these days, however it is important to check.
  8. I wonder if you are on an out of date version...? Click "Edit" -> "Devices setup" and the following screen appears:- There is a "New" button (hidden by the drop down above) that allows new profiles to be created. The red arrowed button then allows you to select which one you want to use.
  9. I use CCDCiel. I like it for several reasons. It really appears to be rock solid. I have managed to crash it once in about 16 months. Even then, I just restarted it and everything just carried on. It operates as a true independent client to either Indi or Ascom servers (or both at the same time!). I like the way that it communicates with Cartes du Ciel. After it platesolves, it can display the current image frame in Cartes du Ciel, so I know precisely where I am imaging. For multi night sessions I usually have the first night's image as a background image in CdC. Once the frame is precisely over the background image, I know that the camera is centred and rotated correctly. In the past I've used Artemis, APT, CCDSoft, and I got on with them all. I tried Ekos, but I didn't get on with it. @ollypenrice, I'm using CCDCiel with a Moravian G3 16200, and it works fine. I tried SIPS, and all I can say is that they really shouldn't have bothered.
  10. Difficult question. I do like the colours in the second, but the first reveals things in a way that I haven't see before - and I really like that.
  11. I like what you have done with the colours. Lovely result.
  12. I don't know much about solar imaging, but those images make me want to learn. I find the top image quite mesmerising.
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