alacant

Hi. Ah, OK. I thought that this seemed familiar. The problem here is that this isn't a dedicated one topic thread, which makes it difficult to decipher the interspersed postings. But that's nothing; many of us here do astrophotography;) Cheers

If you can get the latest version of siril, with its sumptuous new user interface, you'll find it much easier Or maybe even easier, get a linux or windows box for your astro imaging? Cheers

Hi. Mmm. Not sure; what you see in the Baader example is mainly astigmatism, not coma. i'm not sure what camera the OP is using, but I never got the Baader to cover aps-c; get the corners right and you're greeted with fat stars centre. You can't win:( The 2 element sw 0.9 cc does better and is not as fussy on spacing. However to be able to take the cc out of the equation, IMHO you need the 4 element GPU or better. The closest i got was with the Baader (without the bodge of the m42 adapter) was a 4mm low profile filter ring screwed directly onto its m48 thread with a proper wide throat t ring. Remember that the correct spacing on the Baader cc is 57.5mm. A good way of narrowing down the issue is to borrow and so substitute suspect components. Try the local astro club? HTH and clear skies.

Hi Ah, ok. So connect a camera app. I think that using dark frames is going to introduce more noise but YMMV. Cheers.

Is it faulty?

If you remove the camera, yes. Ask here. You may find it easier on a Linux or Windows machine. Cheers

Simply change to your working folder. The one with the files you wish to process. Now hit the sequence tab > search for sequences HTH

That's a pity.

Update to the latest version: 0.99.3. On Mac you'll need to build it from source. Don't take dark frames but instead dither between each light frame. One off: Take bias frames and stack to make a master bias. For each session: Take flat frames. Pre process each flat with the master bias. Stack the pre processed flat frames to form a master flat. Pre process the light frames with the master bias and the master flat. Don't forget to check 'debayer before saving' One off: Put the all the pre processed light frames in the same folder and open as a sequence. Register and stack using one of the clipping algorithms. That's it. HTH.

Hi. A distinct advantage then;) What version of Siril do you have, what camera is it and was it removed between sessions? Cheers

hi These are good. If you're only going to use wide dovetail plates from now on then this will save you quite a bit of weight. Ask for delivery from the European store. Cheers

Hi everyone My Spanish counterparts insist that 7023 is the cúmulo (cluster) within the blue dusty bit. Not that I can see a cúmulo. But they evidently can. Heated argument, almost as hot as the overnight ambient here in Alicante. For this reason I never expected anything but noise, but despite the sensor at 36º+ this popped out. There's even some blue, and I can't do blue! Maybe the dither saved us? One hour up to the meridian on three hot nights, before swinging low to the south for three more failed attempts at m7. Maybe worth an unattended let-it-get-on-with-it all nighter on this one and leave m7 until we can get to the top of the mountains... Thanks for looking and do enter the cluster argument. Or even better, post your findings on the same.

Hi Let's do the collimation first. If you can't get along to an astro club for them to check it... Post a photo through your Cheshire collimator. If it has cross hairs, so much the better. Post another with a simple cap; one with just a hole in the centre to ensure you are central. There's astigmatism so this looks like the Baader cc but you could confirm that too. if so, which connection method for the cc are you using? Cheers

The focus position (the same distance as without a cc) with a dslr protrudes into the light path. Cheers

Hi I doubt that it will be much use out of the box. Remember that this is a low budget Skywatcher telescope. Collimation is easy, but before you have a go, be sure too read the collimation myths Unless you use the gso coma corrector, your dslrs will give you distorted stars. You would shorten the end which protrudes into the telescope by 10mm. Yes. It's a case of removing 4 bolts. Preferably without dropping the nuts down the tube! The focus barrel is soft aluminium. A fine tooth hacksaw eats through it like butter. I'm with @RolandKol on this. dark frames will introduce more noise rather than help remove it. so: bias and flat frames applied to your images with a dither between each frame and stack with a clipping algorithm. If you're apprehensive, you may want to go along to an astro club meeting. It's far easier to learn collimation by watching someone do it. it's likely the primary mirror cell will need attention as well as the secondary spider. They'll do that for you too. They also have hacksaws; they do the work. You buy the drinks. Easy! Good luck and HTH

Hi. No need to dismantle the mount. Mount in home position. Clutches engaged. - move the mount between say 70° to 120° in both Ra and Dec. - loosen the setting circles - disengage clutches - set the home position using a bubble level. - spin the setting circles until you have something sensible such as ra and dec at zero. - lock the setting circles. That's it. HTH

A friend on the Spanish forum sent me this. The accompanying message, '... ¡los ingleses por excelencia!'. English par excellence. For the record, I write English but rarely speak it. Hence I have fewer telescopes than Jeff.

Hi. Move the Ra and Dec gears to different teeth; rotate each say, 90° and reset the home position. There's probably a rough patch or a missing tooth on one of the worm wheels. Cheers and HTH.

Hi You should get good views and you may be able to get video for some of the planets. You may decide upon something else for deep sky objects. Cheers and enjoy.

Perfect. Borrow it for a session and see how you go? I've a feeling you'll be fine with it. Cheers.

Ahhgghh!!!

Hi No theory. Just hands on... We guide a DSLR from a 55mm lens to a 1000mm f5 reflector with a 60mm f4 refractor using a zwo120mm or it's clone, the t7m. Works fine So, to answer your question from a practical point of view, the asi120mm. Save some money that way too;) Cheers and HTH.

Hi If you can control the camera's temperature, take dark frames. If you can't, use bias frames with a dither in between exposures and stack your images using a clipping algorithm. With modern astro-software, you can correct -non flat- fields, but maybe to begin with, take flat frames anyway in case your sensor has dust. With either of the above. HTH

Hi Perhaps the best way to deal with DSLR noise is to dither between frames and then stack with an algorithm which removes the hot pixels. This means taking bias frames (along with your light and flat frames) instead of dark frames. Indeed, you'll probably find that dark frames introduce more noise. HTH

Hi everyone With the heat haze and moisture laden air stream, this was about as far south as we could go last night. Spurred along by EKOS' new SEP-multistar guiding we managed to keep the star fwhm below 3 for most of the session, managing 45 minutes either side of the meridian. But with ambient not falling below 25º, having to rely on a larger than usual dither to help with the noise. Once again, if you're in the star removal business, look away now... Thanks for looking and do please compare notes if you've had a go at this recently. 700d @ ISO800