The Admiral

On Wednesday I took advantage of the very dry and clear conditions to set up for some imaging. But boy, was it cold 🥶. Given the time since I was last able to image it seemed like starting over again! Plus - This is only my third serious attempt at imaging with my new iOptron GEM45 acquired in April last year. This is only my second attempt at guiding, using my new MGEN-3 guider, and my first attempt at dithering. My first attempt at using Astro Pixel Processor (trial version) on new data. Anyhow, I thought I'd post the image with all its faults! On the whole, I'm pretty pleased with the way it's turned out, and as is my wont I've been a bit aggressive with the colour, partially to make up for the lack of red content as the Fuji camera is not modified (though does still possess a modicum of Ha response). Imaging details: 26 subs of 300s (total imaging time 2h 10m) 12 Darks, 50 each of flats, dark-flats and bias. Processed in APP, with adjustment of black point, addition of a little clarity and selective colour intensity, and noise reduction, in Lightroom. Equipment: Altair Wave 102mm Super ED Triplet APO, William Optics Flat 6A III 0.8x reducer/flattener, William Optics Uniguide 50mm guide scope, iOptron GEM45, Lacerta MGEN-3 autoguider, Fuji XT-1 mirrorless camera. The yellow-starred cluster bottom right is the Trumpler 5 cluster. I didn't realise that was there until I processed the image! Pity it's going off the frame. Ian

It bypassed us in the end so we didn't get any snow, just black clouds for a while. Imaging now, but my goodness it's cold out there. At least the air is a lot drier than it has been of late. Ian

GrrRR! This patch is approaching from the NorthEast, despite a clear afternoon!!!!!! Having spent a couple of hours setting up, not pleased to see that. We'll see what transpires. Ian

Goodness me, how does one cope with this uncertainty? Clear Outside has now reverted to tonight being good, tomorrow rubbish, as it was originally! I agree, "feels like -8" isn't encouraging is it, mainly wind chill. Ian

For me, Clear Outside is showing a complete switch from what it was saying yesterday. Now, Thursday looks to be better. However, MeteoBlue has tomorrow to be poor! I do wish the British weather would make up its mind Ian

Hmm, they look like Bahtinov mask spikes 😉. They couldn't be, could they? I'm sure you'd recognize them if they were. Ian

Out of interest, what do the darks look like? Depends on how you take them of course, but if you leave the camera on the 'scope and just cover the end of the 'scope, that might reveal a possible light leak. And just another thought, does the light streak stay the same for all the subs? If it was light leakage then I would have thought it would vary a bit as the 'scope tracks across the sky. Ian

Yes, that 3rd pic is incredible, never seen a picture of anything like that before! It's my go-to Aurora site. Ian

By chance a timely post has popped up which I think illustrates how much difference processing can make. Don't get hung up on the details, but I think the various attempts at processing illustrate the point. It is often said that the various processing applications have a steep learning curve, more so with some applications than others, but it is worth getting to grips with it as it stands you in good stead for the future. StarTools is easier in some sense because it does all the subtle processing behind the scenes which with some applications have to be manually done. It does require a number of somewhat opaque parameters to be set though, but using the default settings does get you a long way. Good luck, your journey starts here . Ian

I've not used SIRIL but DSS (free) is primarily used for calibration and stacking. It can process images, but I don't think many use it for that. StarTools just processes, it doesn't calibrate or stack. It is very reasonably priced, and all features can be trialed before purchase, except it doesn't save. Ian

Good work there. I can't help feeling that with about 1½ hours worth of data you ought to be able to get more out of your M31 image, even if taken at f/10, in particular, a bit of colour. What are you using to process your stack with? In my experience as much comes out of processing as it does with data gathering. True, if you don't get good enough data you can never get a good picture, but good processing can make or break a picture. I've had good success with StarTools. If you can accommodate its workflow, it does seem to get the most out of the data with not a lot of effort. Ian

I'm intrigued. This filter has two narrow passbands (though it's called a tri-band ), but this image looks like a normal RGB image rather than NB. Is this a mix of the two, or is this just what you get with 3 hours using this filter? What am I missing here? Ian

+1 to that! Ian

I am one of a small number of people on the Lounge who use a Fuji camera for astro photography. I didn't buy it specifically for that use, but for conventional photography. I continue to use the earlier 16MP X-T1, so I can't vouch for the performance of other models in this role. The Fuji uses sensors with both a standard Bayer array, and their X-Trans array. The X-T1 is of the latter type. This model also doesn't use a low-pass filter, or antialiasing filter, in front of the sensor (principally because the colour filter array is meant to reduce the effects of moire). As reported, I have found that the the red response of this particular sensor is pretty good, though I haven't found any response curves for it. As examples, here are a couple of images I got which hopefully show the extent of its red response. I am not putting these forward as exemplary images, just to give you some idea. I haven't used an astro camera or modified DSLR to compare it with. I wouldn't want to guarantee that other models are similarly responsive. Another thing that has impressed me is the detail I can get out of the camera, which I put down to a lack of AA filter. Again, no direct comparison with other cameras. Here is an image I took last April. All these images were taken with a 102mm APO with reducer/flattener, effective FL ~ 560mm, ~ f/5.5 , the first two using an AZ mount, the last one an EQ mount. Generally, the sensor is quite low noise, though the above pictures might make you think that's not the case. The total exposures were typically 1 -1½ hours so not that long. In all, the X-T1 is a bit of a curate's egg. The good bits I've mentioned. The not-so-good bits are Fuji RAFs are, I believe, not processable in DSS without first converting them to DNG files using the free Adobe DNG converter. AstrArt does process the RAFs but I'm not convinced that the calibration and stacking is 'by the book' on account of the non-Bayer array. However, AstroPixel Processor has just released a version which has been tested using Fuji RAF files (mine included ). Canons and Nikons are ubiquitous in the astro imaging field and as such there is software available (such as BYEOS) which can interface directly with camera, and fittings are much easier to find. In summary, would I buy one just for astro photography? Probably not. If you've already got one, worth a go. Don't assume that all sensors will behave the same, or else be prepared to invest to find out. Hope that helps, Ian

They are magical displays aren't they. Love to see something like that in person. Ian

It is mind-blowing, isn't it? That's from last night, and there are quite a few similarly amazing displays last night. I would just love to see them in person, but like getting a clear sky in the UK is subject to chance, so is seeing a decent display. An expensive holiday could be quite uneventful . Mind you, whenever I've looked at this site more often than not displays of some sort have been in evidence. They do holidays, naturally........ Ian

For example:

I found the webcam on the "Lights Over Lapland" website shows some incredible displays. Scroll through time and see what you can see. OK, I know it's not the aurora from the UK, but beautiful none-the-less! Ian

Murder weapon in the Hertfordshire Murders 😉. Fully tooled up by the look of it! Ian

I don't know, I think perhaps hi-fi has as many cables as it did, unless you're prepared to use bluetooth links. Not sure I could live with this setup, personally. It needs to be an exhibit in its own room really. Ian

You're right there, even I wouldn't want to sit and look at it😀. Ian

I don't think my wife would appreciate its beauty if my kit was permanently in the lounge ! Ian

Well, if it's a south facing window, wouldn't it be sensible to point the scope down to avoid it catching sunlight? I'd complain if it was being used by looking through the wrong end . We'd booked a caravan holiday in Broad Haven with the kids and this happened very shortly before we went! I asked a petrol pump attendant where we'd stopped for petrol if it had affected visits to the area, and he said that it had. Ian

Lovely image. I prefer the one with stars, they add context for me. What scopes are you using here please? Ian

Thanks Dave, but what I meant is that the mount is now advertised as having "Latest Version with Improved Polar Alignment Adjustment" which I took to be an improved mechanical adjustment, as I know this is an area that was criticised in reviews. Is this not the case as far as you know? Ian