alacant

Hi. Hope by now it's sorted but if not, I think it maybe the secondary displacement toward the primary that is causing the light loss. On my 208mm, the instructions are to centre the the spider -use compases to make certain it is-. then give 3mm (2 turns anticlockwise on the secondary centre bolt) displacement. ES tell me that if the centre bolt is dead centre in the tube, then the required displacement away from the focuser is taken care of. On a quattro that may not be the case and you may have to perform both displacements yourself. I've never believed that proviso, '...may need slight adjustment from factory settings due to handling during transit...' OWTTE. What it should say is, 'Needs to be pulled apart completely, reassembled and collimated immediately upon receipt.'. When you have the cross hairs of the sight tube coinciding with the donut on the primary, does the laser still point dead centre of the primary? Anyway, hoping by now this will all be in the past. If not, HTH.

Hi. It's this image I'm referring to from your first image; the defocused star is not circular. The bottom and right right is missing which changes to top left on the other side of focus. The Cheshire will get you close. For the final star test, you can use live view whilst you tweak the primary adjusters. Or better, have a friend to tweak them whilst you keep the star centered. I don't think you'll be able to reach both manually on a 10" so your camera's live view on a laptop screen is invaluable. Also attached is a view through my Cheshire/sight tube just before the star alignment; notice the offset. HTH. EDIT: forgot to say. Star test. No correctors or filters and with the star dead centre of the field of view.

? Does that mean led is good? TIA

Hi. You're missing a chunk of the star bottom and right ( image 1). The secondary isn't centred in the focuser. Use a collimating cap to adjust the secondary to be able to see all the mirror clips equally. Then use a Cheshire with crosshairs to centre the primary donut on the crosshairs. Then you can tweak the primary to perfection. When I first started doing my f3.9, I thought there was something different I needed to do with low f numbers, whereas in fact it's the same procedure as any other Newtonian. HTH.

Hi. Your setup suggests you're guiding the mount. If it's doing only 20 seconds then I'd look at the software. If that checks out OK, then I'd say flexure is a candidate. Replace the bottom dovetail with a wider longer plate, lose the adjustable rings on the st80 and secure it with its original -non alignable- rings. With your big pixel camera, I'd say it's guidable . HTH and good luck.

Hi. Nice shot. It's a good target for a non-modified dslr and I don't think there is anything to gain by using a modified camera. You could make it really good by taking several shots and stacking them. The advantage you have is that the Bresser refractors have nice flat fields; no need for expensive correctors and flatteners. HTH.

Here we are with another 6 light frames with dss k-s. Maybe the noise is better -I can use a much larger canvas-, but I've lost a lot of nebulosity. I think I'm gonna have to give up for this year. It's still over 30º when m16 is on the meridian with the air still very turbulent. Maybe the best time to catch this would be before dawn, end of June maybe?

6.4s

If you'tre gonna stick with 1.6s then I think you'll need more snaps. IIRC, Tanaka used 400 frames @ ISO6400. HTH.

Hi. It's difficult to help without more detail such as ISO, the lens aperture setting, an example (link to) light frame and the stack from DSS etc. My guess is that the data is there but it needs stretching to bring out detail. Don't give up. It's something really simple! HTH.

DUH. I forgot about this. I took the DSS defaults, which I think are what you chose the previous run...

Hi. Will you be imaging from UAE? If so, you have the advantage that it will be reasonably high and so away from atmospheric currents and light pollution. Have a go tonight maybe? It's due south at around midnight. No filters. I used a 150mm f8 reflector which doesn't need correction lenses either, so it's about as simple as it gets. I use a dslr and find that filters serve only to make processing the image more difficult. HTH.

Good choice. I have the 80mm f5 from the same makers. It makes other brands seem flimsy by comparison and is great for ap.

Hi. The stars look streaked so I'd reduce the exposure say to 10s and keep taking snaps until you just can't any longer. 100 frames perhaps? Lenses: is there a fast 135 or 200mm? HTH and well done for having a go with what was available.

Excellent effort. Even here at 38N it's a challenge, so from UK to get anywhere near is amazing.