The Admiral

When you say made the biggesr difference, can I ask, in what way? Given the other limitations of short subs and alt-az mounts, do you think it would be worth the effort? Ian

Thank you for your comments happy-kat. Well as I've just started imaging I haven't really got a library! I do take darks each session, as long as I remember, because as I understand it they are temperature dependent, so they need to reflect actual conditions. I don't know how critical it is. Bit of a pain when at midnight and you are wanting to pack it in, you remember that there are another 50 x 30s darks to do! I'm now starting to re-use the bias frames from other imaging sessions though. I've not embarked on doing flats yet. Ian

I've not had a go at imaging a globular cluster before, and Steve's M3 was to be a likely contender, but M53 put in an appearance somewhat earlier so I had a go at that. I stacked 47 x 30sec subs, 54 darks, and 41 bias in DSS and processed in Star Tools. I did a bit of tweaking in Picture Window Pro. Equipment: Fuji X-T1 at 1600ASA, through an Altair 102mm f/7 Super ED, all mounted on a Nexstar 6/8SE mount, 7th March 2016. Ian

You can always tell when we've had a rare clear night, there's a burst of activity (and hopefully the atmospheric disturbances aren't doing the same as to this little chap!) Prompted by the rather splendid image of the Leo Triplet (M65, M66, and NGC3628), posted by Barry-Wilson very recently, I wondered what would be achievable using the short subs approach. Here's what I managed to get last night, stacking 95 x 30sec subs, 54 darks, and 41 bias in DSS and processing in Star Tools. Equipment: Fuji X-T1 at 1600ASA, through an Altair 102mm f/7 Super ED, all mounted on a humble Nexstar 6/8SE mount, 7th March 2016. Personally, I'm rather pleased with the way it's turned out, and I hope that you like it too. Ian

Some nice images there Steve. I particularly like the M51; that's one I'll target whenever it's position becomes favourable. I think that there is a hint of colour coming through there too. Ian

Nice results there Steve, and plenty of detail in the nebulae. It'd be worth a try on the Filters tool. Ian

I've had a number of digital SLR/mirrorless cameras over the years, and the noise reduction could be switched off on all of them if I remember correctly. It seems extremely limiting of Sony to prevent that, particularly as it's a simple software switch. Ian

I don't think it is just cost, but also convenience. As one who has to drag all the gear down from upstairs and set up each time I do astronomy, particularly as I can't see the Pole Star from where I observe, an Alt-Az mount suits me just fine. Furthermore, I'm happy to take images which I know aren't top notch, but which at least allow me to visualize objects I'd have trouble seeing visually. That's not to say I'd be happy with any old result, it's still a question of getting the best from the equipment I've got. That's the challenge. One could do live stacking, but then that means even more paraphernalia that needs to be set up, a laptop, something to put it on, cables, a separate camera, whereas an imager in a box (i.e. a DSLR) is pretty minimalist. That's my take on it anyway. Ian

Hear, hear! Ian

Thanks Stuart, I'll need to look at this, re. structure detection and masking. Not at all familiar with those. I've already used the S tab to increase saturation, but found it just coloured the whole image a single colour, following use of the Colour Calibration tool. Early days! Ian

It would be nice to know what you have already done to process it. You probably need more total exposure time, that always helps. Even so, I've taken the liberty of just treating your image to a bit of contrast enhancement and sharpening in my photo processor and you may be surprised at what is already contained in the image. It's a question of teasing it out with the appropriate tools. With an ALT-AZ mount, field rotation is something you need to minimize, but even so, exposures of 30s should be do-able as long as you don't get star streaking with your mount's movement. Ian

I'm not sure whether your comment is a bit tongue in cheek Olly, but I can't let it pass without response . One type of mount might be better than the other for astrophotography (though that would depend on what you want from it), but you can hardly say that one is wrong and the other right. That's like saying for example that a reflecting telescope with an aperture of less than 8" is wrong, and greater is right, or that the f-ratio below f/7 is right, and above is wrong. And as you know, some of the largest professional telescopes use alt-az mounts (not simple ones, admittedly!). Or indeed, into a thread saying that an EQ mount is the 'right' mount. Ian

I don't think that there is a right or wrong, it's equipment that allows one to achieve what one wants to achieve. If this thread achieves anything it is that it dispels the myth that to do any astrophotography one has to have expensive mounts accurately aligned, with guiding to boot (the so called right equipment). Ian

Thanks very much happy-kat. Yes, it is bit gross really; I think in future 30s subs would be more reasonable! They don't half fill up the hard drive! In fact the M106 image has a longer integration time than the Horsehead, using 30s subs. Ian

I am so at sea with PixInsight at the moment. But I managed to squeeze this one out of the pot! After using Advanced Background Extraction to remove a strong green cast, I find that the targets are also left a bit green. Previously I tried Colour Calibration to remove the tint, but this time I used the Curves Transformation to lower the green channel before upping the saturation. I wonder if Colour Calibration removes the colour information too much. Not saying it is anything like it should be, but if anything, it shows I've a lot more to learn Ian

Here is my attempt at M106 and friends. I used ~100 x 30s subs together with 50 flats and bias frames. Other details: Fuji X-T1 through an Altair 102mm f/7 Super ED, all mounted on a Nexstar 6/8SE mount, 10th February 2016. 1600ASA. The original images are quite feint. This first image is stacked in DSS and processed in Star Tools. I'm also trying to get to grips with a trial of PixInsight, and this is what I achieved today after many sweated hours! It needed a lot of stretching; in fact I did it in two stages. The fainter details are more obvious, but there is no way that I could get any colour into the galaxy, like the Star Tools processed one. It is still quite noisy. Any ideas from you experts? Ian