alacant

Hi. No, not piggyback; in the telescope as you're imaging. It's a 2" filter you screw onto the nosepiece to which the camera is attached. I think uv is part of it but you also need to cut the ir, one stops the core of the star expanding, the other the blue halos. There's one filter which does both and controls the way the sensor sees the blue or uv or ir or some combination of them. I'm no expert so sorry can't be more specific, I'm away at the moment but there's a photo of it in the link I sent. HTH

We've a thread on the st forum about reducing the halos, not just in software. I found by accident that there are methods at the image acquisition stage too. On my modified canon the remaining filter is not enough to avoid the stars enlarging. The uv (or maybe it was the ir -tech stuff I don't understand) records as blue by the sensor. A filter will remove all the invisible radiation and in so doing all but remove the blue star halo. HTH.

Great shot. Nice technique. Even better colour. Who needs an apo?!

Hi. I feel that you have less control over AutoDev than Dev. For me, the best way is to autodev first just to see what's there. Then after Wipe has done its gradient magic, use the Develop slider a bit at a time -a bit like seeing the print emerge in the old days of wet darkroom prints-. Just to the right of the slider there's a home-in- button which gets you a good approximatrion without overstretching. There's also dark anomaliy control and a chance to change rgb l values, something else you don't get with AutoDev. That way you have more control over the second stretch than by AutoDev without a mask. HTH. **Î've a feeling we're gonna get thrown off this thread soon as I think we may have gone off topic. Me certainly.

Hi Windows? Try calling it as Administrator. 324 is OK here on both Linux and Windows 10, 64bit. HTH

...which ST tags as compression so will not work with it. You can fool ST into thinking it's not compressed by opening in gimp and saving with no compression then opening in ST. A lot of info is lost whatever; go with FITS. Just my €0.02.

Hi. 700d: 204Mb. You need 64bit and as much Ram as you can throw at it. Make sure that you have no other stuff running before you call ST. If you are patient it will eventually load even in 4Gb RAM -have a beer meanwhile- but it'll be unresponsive whilst it does so. Make sure your /tmp -linux- or ST folder on windows contain nothing but the .trk or ST files respectively. As soon as it loads, bin it -to say 35%- so that you'll be able to process in more or less real time **. HTH **Realistically the only way to be able work with full size stacks is a 16GB machine with /tmp or the ST folder (linux-windows respectively) in RAM

Hi. ST works only with linear -un-stretched and uncompressed- files. For DSS ensure you are saving as FITS and have nothing selected for your camera in the FITS dialogue -unless you are stacking FITS files.

Hi. For me it's not so much a preference, more a necessity. Unless you've a top end gaming machine with oodles of RAM, it's the only way to get stacked and processed before xmas! No but seriously, it's not just StarTools. I'm sure processing raw images takes a lot of computing power no matter what you use.

Hi. Whilst sterling is still worth something (!): http://www.bresser.de/es/Sale/Ofertas-Especiales/Messier-8-Dobson.html

This is cute. Heavy, but cute. Cygnus looks awash with star fields.

EQMOD EQ6 Hi I had a go at autoPEC. I took all the default values but there seems little if any improvement. Also, I'm not sure which file to choose. There are two: pec.txt and peccapture_EQMOD.txt The former is smooth, the latter jagged. These appear only under EQMOD and indicate the folder: C:\Program Files (x86)\EQMOD\PEC but in windows explorer, neither file is visible nor can be seen if looking for hidden files. They only appear in EQMOD. Which file should I load? Any other gotchas? TIA

Everyone: thanks for hearing me out. I've got it now: the mount keeps the camera in the same orientation no mater what the time. That's the answer I was hoping for. Brilliant. Thanks again.

Ahhgghh! I didn't see this. In one post we have orientation dependence, but now we don't. Sorry to be a pain. Could I go back to my clouds example? Say I take 3 exposures at 23:00. Then it clouds over. I leave everything as it is; tracking and camera orientation. The sky clears at midnight. I continue with exposure number 4. Question, is snap 4 the same orientation as snap 3? TIA

Ah, OK. So if it's not oriented RA-DEC it is gonna change. That's a good reference. Slowly getting there...

Hi and thanks for the reply. Are you saying that the orientetion changes? Say I start at 23:00 and take 3 snaps. Then it's cloudy. I leave the mount running until 23:45 when it's clear again. Is the chain still in the same orientation? TIA.

OK. It's been cloudless all day [1]. So, just one final check: if I leave the camera there, it's going to be that orientation all night? TIA [1] Precictions about what will happen 10 seconds into the first exposure anyone?

Yessss! Thanks to everyone for the sanity check. I did get a bubble level but only used it to make the RA weight bar horizontal. The biggest clue was in the camera orientation. Gonna see if I can get more detail tonight. Any tips on exposures would be great. This is 8 x 30s in dss with a blur layer subtracted.

Phew, that takes some following! My camera is still where it was. So I'm not far off if I rotate 90º to where I am and centre on 4438? This is where I get another spatial headache. Instinct tells me I should rotate 90º clockwise. But does it matter? I've 2 batteries and no mains. That gives me about an hour of trial and error. An 8Gb card gives me about 100 shots, although I suppose I wouldn't RAW for trial and error. Just thinking out loud...

Thanks, that's very neat. I take your point about camera alignment. Presumably then, I'd be nudging left-right-up-down relative to the camera frame rather than nudging and hoping? Is there an easy way to orient the camera in ra-dec, say in the home position?

Hi everyone. Galaxy expert needed. I used a dslr which I synscan centred on m84, m86 beneath. I can see m84 and m86 in the finder. I now see m84 was a bad choice. I tried trial and error nudging and taking 10 second exposures. I tried relating what I saw through the finder to what was seen in the camera, the latter only stars. Impossible. 3 hours later, I gave up. Anyway, there's a smaller galaxy , 4438 just out of shot below m86. So, 1. I turn the camera 90º. 2. I centre on 4438 so that m84 is top right. Question: am I heading in the right direction for the chain? Or WHY. Cheers and TIA

Tonight: the planetary in M46 or bust...

Hi I don't know Bresser reflectors but if the quality is the same as their refractors, I'd go Bresser. They also answer emails. HTH.

Ah, OK got it. My telescope came with warnings NOT to look at the sun. I can see I've a long way to go with this astro thing!