alacant

Hi Looks good to me. OK, the image drifted over the course of the session and there seems to be quite strong light pollution from below but cropping and developing brings some nice detail. Cheers and HTH.

Hi everyone The main problem with this wasn't the cluster, rather the orange star toward the bottom which detracted in a greater part from the main target. It gave us a chance to try DarkTable's -rather nice- contextual mask which tamed it well without looking silly. Maybe we took it a bit far. Anyway, pleased with the sub €300 GSO which we deem ready now for the up and coming galaxies. Thanks for looking and do post if you've had a go at this. 700d on gso203: ~40x2min ISO800

Hi Lovely shot and good to dispel some of the myths surrounding zoom lenses when used for astrophotography. A 105-75mm step down filter ring (or a cereal box) will give you f4. With the lens set at f2.8, the diaphragm will be masked, thus giving spike free stars. Not sure if they'll hold up the toward the corners of the frame though. Cheers

Hi Thanks for posting your image and no, no idea about the galaxies. I think that with our DSLR, we'd need significantly longer frames to get anywhere near your definition. Lovely shot. Cheers

Hi everyone The coastal strip at Alicante is narrow and the plain rises abruptly thereafter giving poor viewing to the west, so here at least, this kinda represents the end of milky way stuff until summer. Time to get the OAG on the long reflector. Never very good with blue stars, but this seems OK as -it says here- mainly old red stars. Thanks for looking and do post if you've had a go at this. pn208, 36 x 90s

Hi The settings are: EKOS: always reset guide calibration. PHD2: reuse calibration Check/uncheck as you wish. I'd recommend EKOS' internal guider however who's recent SEP-multistar implementation is both predictable and accurate; one fewer app to have to juggle. Cheers

Hi Not so much the individual pixels or even clumps of noise, rather the pattern left -quite often bands where many pixels are set across the whole frame- by non optimised dark frames. On the older 12mp sensor however the only way we've found to remove the banding pattern is via a master dark frame calibrated using Siril's dark optimisation. Newer sensors don't need this. Your 200p is as clean as they get. Cheers

I think I can see your error. Common mistake. It's all in the adverb. Garage you say? OK, so clean the car's windscreen. Now take out the mount as if it's getting in the way of the cleaning. Return to the car and clean some more. Now, and this is where you went wrong, casually place the telescope on the mount. The clouds would be none the wiser. Works every time. HTH.

With most targets which would benefit from modification of a DSLR -I think maybe at your latitude until autumn (?)- sinking rapidly in the west after sunset, the CC. Cheers and HTH.

Hi You may find that you need significantly longer than the OP's 80 minutes to get comparable detail. Cheers

Hi There's a lot of negative hype written about this, usually sourced from old posts when f4s were first mass produced with their hopeless mirror support, inadequate metal tubes and rubbish focusers. I'm certain early adopters all those years ago did indeed suffer, but it's 2021, the issues have been addressed and as @Stu Wilsonmentions, the only essential modification needed for his GSO was replacement springs for the main mirror. I am at a loss as to why the OEMs can't address this simple upgrade. Proper ONTC grade springs cost just €2.30. For a pack of ten. Cheers and HTH

There are other methods for producing flat frames such as using a t-shirt over the telescope aperture and e.g. pointing at the sky, but they're a bit hit and miss. A light panel costs less than €10 and makes the production of flat frames consistent. I'd recommend one. HTH

Oops, OK. Sorry. This then:

Yes. Flat frames really aren't optional. You're making life a lot more difficult without. Unless you've the 12mp sensor or (one which is at least ten years) older and unless you take them at the same temperature as the light frames (with an unmodified dslr you can't) or have a decent dark optimistaion algorithm (e.g. the one in Siril, but even then...), they will add more artefacts. Much better to use Light, bias and flat frames only, dither between the light frames and stack using a clipping algorithm. Cheers and HTH

Hi Yep. That's the one. Cheers

Hi It's Telia's first myth: you have to square the focuser very accurately. Seronik takes this slant upon the same. A guy at our local bar astro group got me to draw the ray diagram. To scale. Until I did, I couldn't understand either. **EDIT: three things I forgot... - so long as they remain fixed relative to each other, the mechanics don't matter. By collimating -especially using a Cheshire tube with cross hairs- any tilt of the focuser is neutralised. - the secondary mirror has no optical properties other than reflection. - draw the ray diagram with the focuser at obviously differing angles to the tube. This one really does drive it home: all you do is tilt the secondary. Remember, it's just a flat mirror. Cheers

Hi The acquisition looks great. There's some lovely detail hiding there Here is the luminance of the stack from the light and bias frames. Best not using dark frames with a 1300d. Could you post -a link to- the flat frames too? They would allow us to lose the dust, the vignetting and enable much easier processing. Cheers

Yeah. Know the feeling. Always best to leave it until the next day, but before the pub! Amazing detail for such a short time. Love it. One thing you may want to check are the flat frames. I made synthetic flat frames with StarTools but still had to lose quite a bit around the edges of the frame. HTH EDIT: forgot. Stu, is there a filter? I can't get much if any colour from the stars...

Hi I'm not at all convinced by the l-enhance, which to our eyes shows little if any advantage over a UHC, but costs €significant more. I've put a little evidence here. Of course, YMMV but I'd certainly recommend borrowing and trying before committing. If you've already narrowed you choices between the two however, I'd go with the l-extreme. The evidence I've seen with the latest generation OSCs paired with the l-extreme or other dual narrow band filters seems to suggest that may be this is the way forward for high end imaging. But try soon of course as suitable targets are sinking rapidly west after an alarmingly -at this time of year- later and later sunset. Cheers

That maybe the way high end imaging is going. The likes of the l-extreme with the new generation asi2600 for example gives you H and O without the hassle. For the rest of us, Siril has excellent algorithms to extract the H and O wavelengths. The narrower the filter the better.

Indeed it is. I think however it is more important that after your 1 minute tweak, the collimation holds at any telescope angle though the session, not simply at the angle of the telescope at the time that the collimation is performed. We haven't found a cheap Newtonian that holds out of the box without modification. But hey, we're imagers and so probably have no right posting here anyway. Hoping it may help though. Cheers

Taken on consecutive nights at the same site: eos700d. To look at and through, the filters seem almost identical. Here is the L-enhance. Here is the UHC: Here is the maths: Both with sub €300 telescopes. Unfortunately still anecdotal as not a true side by side. Sufficient however to convince me... Cheers

Taking this the other way, I'm not sure what advantage the €150 L-enhance is supposed to have over a €30 UHC. Same effect. Different price. DSLR. Still thinking, although not many targets left to test until May/June time. Cheers

Hi Maybe post -links to- examples of each file type? That way we maybe able to pinpoint the problem. Cheers

Hi Assuming you're leaving the telescope with the poles extended, the best way we've found is to forget the retaining bolts and instead fit stronger springs, 1.6mm wire compression springs replacing the three existing items and fitting the same over the retaining bolts giving 6 springs altogether. The latter remain loose and are there simply to retain the 'passive' springs. Collimate once with three screws instead of twice with six;) Finally, remove the mirror and fix back in position with a blob of silicone sealant over each of the cork mounting points, thus preventing lateral movement. Springs available here. HTH