barbulo

I normally use DSS or SiriL for calibration, registration and stacking, but heard about SiriL IC (SiriL Image Converter) and decided to give a try. This was the outcome: While same files processed in Siril, using the OSC_Preprocessing_Withoutdark script, resulted in this: (Both images displayed in SiriL's histogram display mode) The workflow used was this using these parameters I've tried changing the stacking parameters and without calibration frames, always with even worse results. Any clue of what's going on? Thanks in advance.

Hi and welcome to SGL. Yes indeed, AP it's a dark side where your bank account gets emptied and people don't come back from.

Flat frames must be taken maintaining the very same optical path as the light frames: same camera position, same filters, same focus position... Otherwise, they are useless. Normally are taken at the end of the imaging session.

Take them with the same gain/ISO as the light frames and a exposure time such that the peak of the histogram is between 1/3 and 1/2 (mid-left). Put a white t-shirt or blanket and point the telescope to an even source of light (light panel or tablet screen with white background). Take between 20-30. They may appear white or light gray or blue, depending on your camera and filters. If you stretch a valid flat you will see some kind of gradient. If you overexpose or underexpose those, they won't help you that much. Moreover, depending on your camera, you might need dark and bias frames as well. HTH.

I'm far from being an expert but, are you using flat frames for image calibration? Surely they will help. Before background and green removal I crop the image and do a photometric color calibration. After that, do the background and green noise removal and then I move to Photoshop for the non-linear post processing.

Fully agree with @Shibby: with a Canon DSLR you shouldn't bother using darks; use flats and bias frames. Flats will eliminate the gradient or vignetting caused by optics, not the one from LP though. This has to be removed in post-processing.

With my Canon 600D I use 10s and ISO 800 or 1600. Works with 5s too.

That's what I do with a DSLR.

Hi and welcome to SGL

With the same imaging setup, I use around 10px (if I remember well). I use APT + PHD2.

I guess BIN 1 in the OSC version refers to the standard RGGB 4144x2822 px, and BIN 2 to 2072x1411 px. Don't have this camera though.

I don’t know if this counts as astrophotography equipment: Clear and dark skies; a small cottage in a sunny country.

Yesterday we had around 3 hours of clear skies. Instead of weeping for joy, I decided to get the equipment out and give a try: NGC281 (Pacman Nebula) with Canon 600D (mod), 68x120s usable lights @ISO800 + flats + dark-flats + bias. Stacked in DSS and post-processed with Siril and PS. Still some coma in both top corners. I'm starting thinking sensor tilt is the source. I'll give a try with another camera some day. Autosave002.fts

Hi and welcome to SGL.

Hi and welcome to SGL and to 40’s (AKA block 4).

Hi and welcome to SGL

I strongly recommend not to bother aligning the polar scope reticle to place 0 at the top. I had a bad experience in the past. Just check it is collimated by pointing the reticle to an object (can be done during daytime) and rotating the AR axis. If the object is still in the center, it is Ok; I wouldn't touch anything. To do the polar alignment I put Polaris in the center of the reticle, then move the mount to one side using the AZ knobs. After that, rotate the AR axis to put a reticle's horizontal axis over Polaris (use the closest, don't bother placing 0 in the top). Finally I do the standard polar alignment placing Polaris in its correspondent place, regardless where the 0º is placed. HTH.

Don’t forget flat frames.

I don’t think they help at all since the temperature of the lights is not constant and the temperature of the darks cannot match by any means. I don’t use them. When one enjoys 1 or 2 clear nights per month one can’t afford taking darks.

Hi and welcome to SGL. IMO, those plus a good lens are going to work far better than that scope.

I don’t think there will be any difference with such a small sensor in terms of vignetting. I’ve used it without the 1,25” adapter and directly to the 2” eyepiece holder. Never used a T-ring adaptor.

Hi and welcome to SGL.

I use the 130PDS with a Canon 600D and a Baader MPCC. The back focus of the CC is 55mm to the sensor. The problem with some newtonians (not the 130PDS) is that they don’t have enough inward focus distance to reach focus. PDS series have a shorter focuser to prevent that.

Hi and welcome to SGL.

Hi and welcome to SGL.