ollypenrice

Well, the result's great so there's no problem. But I do push the colour at the RGB stage myself, then maybe again later or during the iterative addition of Lum. Olly

If I were still a teacher I would have a new weapon up my sleeve. I would approach a troublesome child, glare at it fixedly for ten seconds, then turn to class and say, 'Dessicated microbial life!' Olly

Just to throw this in: oval stars do prove bad tracking but round ones do not prove good tracking. Equal error on both axes gives round stars. Olly

That's how great pictures are made. Onward!!! 😁 Olly

Very, very nice indeed. I think you could chip away at the core to get a bit further in, though maybe that's for later in your plan? Olly

Telrad. They use proper batteries and last forever. (OK, maybe not forever but my oldest is about 25 years old.) The others I've used require daft little batteries that peg out if you forget to turn them thing off - and you will - or pack up randomly for some other reason.) Telrad. Olly

He is saying but we can't hear him through those damned masks! 😁lly

What the garages tend to do with fuel crises is impose a maximum sale of a small volume when what they should do is obviously the reverse. If they limit sales to a couple of gallons everyone drives around all the time with full tanks, so the available reserve is locked up in those tanks. A minimum volume restriction would mean tanks not permanently full so more fuel available. Something I've seen occasionally on the net is a specialist item like a telescope offered for sale at an utterly ridiculous price, far higher than new. My best guess is that the vendor is hoping to hook a buyer with no prior knowledge of the item and too daft to look it up. It's a big internet and you only need one... Olly

This confirms Greg Parker's analysis of the same problem. There's an easy Photoshop fix if ever you do want to get rid of them. The routine is best saved as an action after the initial selection. Select with magic wand then expand by (say) 7 pixels, feather by (say) 2 pixels, then Filter-Blur-Radial Blur set to spin and best quality. Deselect. Whether it improves the look of the image or not is up to personal preference I guess, but that's how the fix works. Olly

There's always a better way to do it than by black clipping. What processing software are you using? Ah, your post while I was typing has answered my question! Have you tried the gradient removal tools? Olly

You're trying to warm, very slightly, the glass of the objective or corrector. This has quite a high thermal mass and you can only heat it from around the edge so it is best, in my view, to heat it from the outset. I've used both 'full power only' and variable dew heaters and never found any difference, really. It's more important for battery powered systems. Olly

Very good. The star suppression is producing a little mottling, I think, but it still looks great. Your framing is absolutely inspired. That sweeping arc ) from top to bottom, crossed by the extension of IC410 at right angles, gives the image a rhythm and sense of movement which I've never seen before. Olly

Those 'inverse lighthouse beams' are not unusual and appear in my Tak FSQ106 on bright stars. What's more troubling is that you only have one clear one - on the left, but there's evidence that the other side is trying to produce one as well. You also have another asymmetry: the red channel's stellar image is offset to the upper left on most stars. I'd ention this to the supplier. Olly

H alpha signal is almost always faint, meaning it needs long exposures to capture. If you can't track you can't do long exposures... so I think that answers your question and confirms the golden rule of mount first. Olly

I find it hard to understand how a flattener-reducer can do as Starizona claim. The reducer provides a 0.65x reduction factor and produces pinpoint star images by correcting for the field curvature and astigmatism present in standard apo doublets and triplets and RC/ACF telescopes. What is a 'standard Apo doublet or triplet?' They vary in field flatness so how can one flattener perfectly fit all? On top of that, 0.65x will take your Esprit down to F3.6. If you asked me how realistic I thought that was I'd have to say, 'Not very...' Takahashi, at a prodigious cost, manage it with their reduced FSQs but, even then, they don't do so reliably as plenty of frustrated owners testify on astronomy forums world wide. Personally, if I wanted a wider FOV than you're getting at 550mm, I'd just use a shorter FL scope. I'm not being very helpful, I know, but I wonder if you're not seeking the impossible. Olly

You really need a tracking equatorial mount for anything but short focal lengths. The better the tracking mount the better the pictures - and increasingly so as you go up in focal length. There is good free software (Deep Sky Stacker) for combining multiple exposures and GIMP is an alternative to Photoshop for post processing. The Skywatcher Star Adventurer is a good minimalist tracking mount. From there it's onwards and upwards in both performance and price. This is a good place to start: https://www.firstlightoptics.com/books/making-every-photon-count-steve-richards.html Olly

Ha is well short of IR. Ha is around 656nm and IR begins at 700nm. Olly

I'm not a DSLR imager but I've read plenty of good DSLR imagers who say not to bother with darks but to use a master bias as a dark and a large dither (12 pixels or so) and that makes sense to me since uncooled darks may be all over the place on real temperature. In any event, noise is specific to the sensor. Olly

I don't think donuts will be created by bad seeing. The stellar image may move around during the exposure but the central part of the star will surely still get the most light. Olly

There is a (dodgy!🤣) Photoshop fix for elongated stars. It's very quick. 1 Copy Layer. Set Blend Mode to darken. 2 Filter-Other-Offset. Move the offset a pixel at a time in one axis and then the other till you get round stars. (Use the keyboard rather than the sliders, which are too coarse for small movements. 3 Flatten. Olly

Very good point.

I think it's just soft focus. I've never felt the need to use software to interpret the Bahtinov mask image and when I check my visual B-mask focal point against an FWHM measurement I find it's right. I'm not a fan of software for software's sake. I disagree with Nicolas when he says, '- Guiding performance: no, poor guiding will not result in round stars.' If the tracking errors are of the same magnitude on both axes then you will get round stars but they will be larger than they should be. We saw this when initially testing guide parameters on our Mesu mount. As we optimized the parameters the stars became significantly smaller. This is an unusual situation but not an impossible one. It also shows that round stars are not, in fact, reliable indicators of good tracking. Once you have robotic focus working it should give you the best result but I just do it by hand and check regularly. Olly

Lovely. It's impressive that the OIII and Ha regions which we see distinguished in HOO narrowband images are also distinguished here in OSC. Olly

Back off the noise reduction! It dominates the image. Don't be frightened of a bit of grain. Olly

Lovely, and rather like the PacMan in structure. Olly