alacant

Hi Use a bias as a bias. There's another trick you can try in Siril to which some dslrs respond, that's dark optimisation where the light frames have been taken at diffent temperatures to the dark frames. Subtract the master bias from the dark frames then stack the dark frames using median stacking. You now have three entries in Siri'ls post processing one each for bias, dark and light. Of several dslrs I've tried, only the eos450d gave better results with dark frames so do let us know if you try with your 750. Cheers

Hi £150? How about a 72mm flat field triplet? Cheers

Hi Lovely images and good advice about losing the dark frames. In Siril though, use the bias as a bias; it will eliminate the 6i's banding. Dither between light frames and try Siril's linear clip algorithm for stacking. I wish someone had recommended a fast reflector when I first began. I spent a year with a miserably dim refractor before seeing the light. Sorry for the pun. Couldn't resist! +1 for StarTools. It will eat that background alive:) Cheers

Hi everyone With our OAG on loan, we resorted to an old 60mm guide telescope and remembered to fit the ir filter in the equally ancient asi120. The sky would have easily supported 10 minute frames last night but due to the hardware limitation, along with reading too much about the impossibility of using separate telescopes to guide anything longer than a 50mm camera lens, we decided upon half that. Anyway, once again, the little guide telescope did it's modest job well. No shortage of galaxies in the frame and even managed a bit of blue in one of the stars. Thanks for looking and do post if you've had a go. 700d on gso203

Hi everyone Apart from the haze, can't think of any decent excuses for this one. Handy targets whilst you're waiting for the galaxies to rise. My gf deems it, 'not as sparkly as I'd like'. Ah well... Thanks for looking and do post if you've had a go at this. 700d on gso 203

Hi everyone Our yearly visit to Ursa Major. I don't like guiding 1000mm with a separate guide telescope but at least I finally got around to treating the guide camera to an ir filter. Except that I forgot to fit it. So we still have dreamy fat stars to guide upon. DUH! Thanks for looking and do post if you've had a go. 700d on gso203

Hi Sorry. Only just seen this so probably too late now. Anyway... Wait for the luminance filter so you'll be able to get longer frames or if you're satisfied with the way the existing 12 hours turned out, move to something else? Cheers

Hi everyone The steady atmosphere worsened as the night ground on. The EKOS scheduler finally called it quits around the time Cor Caroli all but disappeared behind the haze. This is a noisy example of what an old DSLR can do with cheepo beginner's hardware. The highlight of the session though should go to the software. EKOS' SEP-multistar kept the guiding sane throughout. Only one frame was dropped -immediately after the unattended flip- in the early hours. Thanks for looking and do post if you've had a go at this. 700d on gso203 4h @ ISO800

For your image, absolutely not. I used 25% as I was using a slow computer. It was however solely to demonstrate the process, not to produce a competition winner;) Using the Bin module, aim for boosting the signal without losing detail. The 71% preset is a good place to start.

Hi Glad it was useful. That's the hard part. What follows that is the easy bit. As your data is held in a database, you can now go backwards and forwards as many times as you like through the -same and the extra goodies- modules (to make it look nice) as if the data was still linear. As a matter of interest (this issue comes up regularly) could you say what bit you were missing/got wrong? You may want to move to Siril for your initial calibration and stacking;) Cheers

OK, no use guessing;) I uncompressed your Autosave.tif. Here is the first stage of heavy lifting (the bit everyone gets wrong!) in StarTools, Ubuntu 20.04. Using the world's slowest device; any video editing would be painful. Sorry. Can you see which bit you may have missed? If not, record your own session and we'll take another look. The StarTools log would also help. Cheers

There's a Zeiss here: https://www.ebay.es/itm/Carl-Zeiss-Jena-DDR-135mm-f3-5-MC-S-M42-Lens-/274710705989 And a Takumar here: https://www.ebay.es/itm/Lens-Asahi-Super-Takumar-135mm-F3-5-M42-Mount-Ref-192034-/164689293847 Loads more by searching the same source. HTH.

Hi Perhaps not a good idea. The glass in the fd adaptor renders the lens useless for astrophotography. Maybe consider an old Zeiss or Takumar 135 instead? They're available at around €50 and the adaptors m42-eos -at around €2- do not need a lens to reach infinity. Of course, YMMV but maybe best to cut losses on the fd adaptor? Cheers and HTH

Hi Please describe how you converted the file you posted in the original thread, the StarTools log and a screen record of your StarTools session. Otherwise, we're just guessing. Cheers

You cannot use the file you posted in starTools. The file must be converted and saved to either uncompressed tif, fits or png. In the example you have shown, it has not been processed correctly with either the Wipe nor the second AutoDev after Wipe modules. You may want to have a look at the quick-start. Cheers

I used Siril.

Yes. Unfortunately DSS saves with tiff deflate. If using DSS, save in fits format. Or switch to a better calibration app;) I converted your deflated TIF to uncompressed TIF using Siril. Not ideal. StarTools uses the data, the whole data and nothing... etc. Nothing less will do. Cheers

The larger the secondary mirror, the greater the obstruction in the light path. Most noticeable as a reduction in contrast. If you are not tied to the 150p, the 150pds will also work with your 600d. Budget sw focusers for ap? My experience is unsuitable for publication on a family site. The OP needs a coma corrector which moves the focal plane away from the tube.

Ah, OK, As you're going to need a coma corrector anyway, this one will enable you to reach focus easily with your dslr without having to move mirrors, cut tubes, or use Barlow lenses. The big advantage of this combination over the PDS is that you get to keep the small secondary mirror. HTH

Hi Which focuser does it have fitted? A -link to a- photo would be best maybe.

Hi Which camera?

Hi Yes. With Bresser's version of the 150. The Baader cc didn't cover aps-c properly -astigmatism mainly- so we went with the 4 element gpu. This has the advantage for us that it also gives corner to corner with our pn208, f3.9. With the 533 however, you're using only a small fraction of the field of view so most ccs should be fine. You may just be ok without, correcting any imperfections in software with the distinct advantage of the light not traversing any glass en route to the sensor. Cheers and HTH.

Hi Yeah, unfortunately the FD to EF adapters need an -usually poor quality- optical element to reach infinity, thus no good for AP. Your Takumar 135 will provide corner to corner stars over APS-c at f5.6 but with only 24mm aperture at that setting, is going to be painfully slow, as I'm sure you've already discovered. Faster than f4 at 200mm is gonna cost €silly but if you want to take a risk, there's a Zeiss 200/2.8 beast lens on e-bay ATM. Aperture 71mm although I think it's going to have to be stopped to tame stars, the advantage being that it was designed for flat fields over full frame. The central APS-c bit should fare well. Cheers and HTH. **What do you think about the idea of a section for old lenses for AP?

Hi Just follow the StarTools modules down from the top as I've indicated. It takes about 5 minutes. HTH

Yes. I used StarTools. Cheers