ollypenrice

I have plenty of problems in processing for full size zoomed viewing, Rodd. It's just that I feel like a cheat if I don't! In this one the big problem was the noise in the colour layer, which is a technology issue, I think. I did far more NR than I'd like to do. I used custom techniques based on zooming in to pixel scale to see what was going on. Since I can find nothing wrong with the cooler on the camera I'll have to look at the usual suspêcts like the USB leads, etc. Olly

It's important to be clear that ALL electronic cameras are monochrome, including DSLRs and 'one shot colour' CCDs. We don't 'colourize' * and we don't invent colour. We measure it. In terms of colour there is no significant difference between a mono and a 'one shot colour' camera in terms of how the colour is obtained. Both use a red filter to block green and blue, a green filter to block red and blue...etc. In a 'one shot colour' these filters are placed over each pixel in a 'Bayer Matrix.' Red, green, green, blue - repeated across the chip. (Why two greens? Because it works in the daytime but is a very bad idea at night!) In a mono the imager shoots through an R then a G then a B in turn and combines them later - but the idea is the same. The same kind of software calculates how to weight the three colours of light. My main point here is to stress that there is no such thing as an electronic colour detector, as yet. They are all mono and they all use filters to work out the real colour. Olly * That is, in natural colour imaging, which is what I do in deep sky photography. I have invented colour from purely mono images in solar imaging. This is always declared. The colour in this image is pure invention:

That's the planetary, Paddy. I don't know if the bright star visually centred on it is the progenitor. I'd be surprized. It seems too bright. Probably line of sight. Olly

I only noticed it in SkyMap when planning the framing. It isn't a popular target, it seems. Here it is with 1.5 Hrs of OIII from guest Ton's own TEC140/GM1000/QSI683 Astrodon. 3x30 minutes, guided. (And with its poor neck wrung in Ps! It shows OIII is the way to go, though.) Olly

Yes, that's the one. In fact our present guest shot 1.5 hours of OIII in his own TEC last night and we've just blended it. It's nicer. I'll update the pic when I get a chance. The SCT project went on 'hold' because the idea was to mount it on one of our robotic guest's mounts, a GM1000, but he had so much trouble with it that he took a refund and is now using an Avalon which is too small for the SCT. However, I have a second Mesu coming next month so I'm aiming to give it a run on that. Actually the ODK data was very soft. I guess it was down to poor seeing but I can't remember. The resolution was much the same as in the TEC data. The problem was poor S/N in the TEC colour because the camera isn't happy for some reason. I like to have equal amounts per channel of L,R,G and B becaue it makes processing easier. However, with the usual Photoshop thuggery you can work with two or three times as much L. I perfer not to when possible, though. There are no ODK stars in this. They would have added spikes. There was no star reduction here other than on the handful of bg ones, which I pulled down in Curves near the end. Olly

LukeBL posted a nice NGC4725 recently. Here it is again in a wide field which includes PNG339.9+88.4, the tidally distorted galaxy NGC4747 and the Sbc galaxy NGC4712. Plenty of faint fuzzies, too. NGC4725 is a barred spiral with prominent ring structure. One of my favourites. I've a suspicion that this camera isn't cooling properly so the colour was a real fight and the Ha I shot last night is scrap. The PN shows well enough in LRGB like this and I've emailed a query to Atik to ask if the FITS header temperature is a record of what temp I set or whether it is a measurement of the real temp. (It was showing -25 but I'm not convinced.) The day was saved by using old ODK14 data for colour in the three galaxies. Once we have the technology sorted the addition of Ha and OIII for the PN would be nice. TEC140 and ODK14. WIdefield L 4Hrs, RGB 1.5 hrs per colour. Similar exposures from the ODK14. Enough excuses, here's the pic! Best seen in the larger size. Click on the image and full size button is lower left. Olly

As I said, I'm not aware of anything to beat DBE. That means what it says - I'm not aware of it. I don't claim that it doesn't exist! I'm not in the business of trying every new bit of software that appears on the market and I suppose that I'm mainly motivated to try new software when I see an image that breaks new ground. If I think, 'How did he or she do that?' then I'll be in there, full of curiosity. I'm hardly a PI evangelist, I'm manly a Ps imager, but DBE is profoundly impressive. If you have an alternative, tell us about it. Give us some demos. I'm all ears, I promise. If there is something out there which is more sophisticated than DBE - great. Olly

Just think about what your imaging hardware costs. It's a lot. Now think abut how much of the final image quality comes from processing. It's also a lot! It's more than a lot, it's going to be something like 80%. You can't process rubbish so the hardware is very important, but a good capture is no more than the collection of good raw data. You still have to do something with it. My captures are no better now than they were ten years ago but my processing is a lot better. DBE in Pixinsight has no rival of which I'm aware. I still think the software giants are PI and Ps. Look at the images 'out there' which you like the most and see how they were processed. Olly

I don't think there is much doubt amongst historians that Hooke did have a role in giving Newton a cenceptual, though not a mathematical, leg up on his way to his theory of gravitation. Of course Newton would never admit this. When Newton said he had seen further because he stood upon the shoulders of giants he was, in fact, taking a swipe at Hooke who was deformed and dwarfish. There's a geat Hooke biography byu Stephen Inwood which I have read and another by Allan Chpman which I have yet to read. Olly

No point in my repeating my enthusiasm for this mount. Hope you're as happy, Harry (and Steve.) Olly

I have to say that it looks very like PA to me. On what basis do you say that PA seems good? The simplest test is to take a 'first' image and a 'last' and combine them, then look at the edges of the frames. Any disparity in the alignment of frames, assuming reasonably round stars, comes from PA. Olly

An unusual look and feel to this one. Sh2 126, 2 panel HaLRGB, twin Takashashi FSQ106/fill frame CCD, Mesu 200. The 'Breaking Wave' extension around Gamma Cass, down to the Pacman. 3 panel, twin Taks. NGC 2170 using twin Tak and TEC 140 data. 35 hours. Beverly Hills here we come. A joint effort with Mr and Mrs Gnomus. HaOIIILRGB, 35 hours. And finally IC447, LRGB TEC 140. An eleven hour quickie! As ever, the kit is co-owned by myself, Tom O'Donoghue and Yves Van den Broek. Thanks guys and guests, a good year. Olly

The speed of the system is not linked absolutely to the F ratio rule in AP when using reducers. If you are interested in everything that fills the frame then the rule applies in useful way. If your real target is a small discrete object framed by dark sky which doesn't interest you, then the F ratio rule does not apply. (It becomes the F ratio myth.) The photographic F ratio rule is predicated upon varying the aperture. A focal reducer leaves the aperture where it was and alters the focal length, so it brings in no new light from the discrete object. The two situations are entirely different. I wonder what the effect of binning really is on this CMOS camera. From what I've read it may bring no increase in signal to noise, in which case why bin at all? More homework needed! I like many aspects of the camera so I'd better get studying. Olly

Sorry, I hadn't noticed the dates - but I've had worse!! lly

Imagine what would happen if they put Robert Hooke on the pound coin while they were about it... Oo-er missus. Olly

Firstly you need to be slightly misaligned. I've never actually set out to misalign, I've just exploited the misalignment that was there already! (By not endlessly refining the PA but settling for a 'close enough' alignment.) You then disable the guiding in Dec on one axis and see if that's the axis you do or don't need to guide on. If the mount guides in Dec that's fine. If it drifts off target you need to re-activate the direction you disabled and disable the other one. Write down the result of this test (if you're anything like me...) and reverse the disabling after the meridian flip. Olly

It's good to see Takahashi doing something about the issue. Hope you get sorted. Olly

It's very well known and certainly not my idea. I find it works, though. In saying that if some subs are good and some not it cannot be PA, I should have added 'while imaging the same target.' Olly

Has to be the winner! lly

Not a bit of it, Ron! I had my first mobile only about a year ago and it's a flip phone designed for grandmas, according to the sales person who dealt with me. I can never find it, hate being cluttered up with it and can never remember the number when people ask. I dont 'txt' under any circumstances. I consider the thing to be one step up the food chain from rap music... lly

Smartphone? What's that? Olly

Mine too, though I don't get much rotation so far as I'm aware. Olly

Given that it took over 200 years of telescopic astronomy to find the stellar parallax on a baseline of two astronomical units or nearly 200 million miles I think we can safely dispense with the idea that it arises from the distance between one side of Rob's pier and the other. We all know that he's a stickler for fine resolution but... If there were neither cone error nor non-orthogonality then surely the images would have to align perfectly. So what can it be? Non orthogonality of the camera? When the mount flips, any difference between camera angle and lines of RA and Dec will turn into twice that angle of difference between the image before and the image after. Also, when we align our cameras along RA and Dec, by slewing them while exposing, we are doing so with any cone error already in place, so that cone error is factored into our alignment. Now surely this error we have factored in is 'sided.' That is, it matters which side of the mount we are on when we carry out the procedure. Again, any error will be doubled when measured as a comparison between 'before' and 'after' images. And to take this a step further, won't the cone error we have factored into our camera angle be local to the area of the sky in which we carried it out? In a nutshell there is a complex and interactive relationship between cone error and camera angle. Olly

Yes I know, I'm a dinosaur - but all this 'stuff' can (and often does) eat up a perfectly good night's imaging. Software automation can be like kids and homework. They will spend more time and effort on finding ways not to do it theselves than it would have taken just to do it. Now Springbank never did anybody any harm.* Olly *This is not a quotation from the BMA.

Humph, robotic focus. Any of you guys host five robotic scopes? I do, and I also host five fingers on each hand and they are not connected by USB.... lly