Demonperformer

Some nice images starting to come out of this setup now. Are you using the camera lens at its full f/2.5 to get that much data, or have you stopped it down at all? Thanks.

That sounds like an interesting idea. I, too, run everything off a win7 machine (laptop), but have been considering getting another 'dedicated' machine for running everything at the scope, but the cost of (even 2nd hand) laptops would be a bit of an extravagence for me. However, a quick look on google, reveals some pi3's for sale in the £30/35 region. And not having to run windows would be an added bonus! Do let us know how you get on, if you do decide to go down this route. Thanks.

Gina, I am no expert, but a quick google suggests that depending on the speed of the device, 3 or 5m is the maximum. I gather you can get some sort of 'booster' to push the length further. You will know your own system best, but it might be worth considering if this would solve the problem better, as new cables of the same length might not help if you are pushing your devices to the limit of length. But, as I say, I'm no expert.

That's good, Gina. Hope the view at 1500 light years is better than 5 miles .

Looking at the weather forecast, I suspect (imaging-wise) the moon might be the least of your problems tonight ....

Gina, Not sure if you have this link, but it is great for setting up AT - which (contrary to my views on its PA-ability) works wonderfully at plate-solving. http://www.lightvortexastronomy.com/tutorial-setting-up-and-using-astrotortilla-for-plate-solving.html

My 2p (and it's probably worth a lot less than that) ... I would think that something that would pay real dividends when set up would be your triple 400mm NB rig. I'm sure the EQ8 would handle that with ease and considering the amount of time needed in each bandwidth, being able to take all three at once would seem to have major potential. I'm presuming that you would only need to guide on one scope and success would be dependant upon how solidly the scopes were held together. Thanks. And you are going to love the polemaster ... so simple even I can do it!

From my (extremely) limited use of flats, I seem to remember that it helped if I took half of them, then rotated whatever I was using to diffuse the light (be it tea-towel or anything else) through 90o and then take the other half. That way, any irregularities in the "diffuser" get cancelled out.

Nige I believe that is what is knwon as snatching victory from the jaws of defeat

Yes, it certainly can be done. There was a thread on here years ago with an image of the horsehead nebula taken with a massive number of 2-second subs.

Most of my imaging has been done using an altaz mount. My passion has always been open clusters and one of my most satisfying was getting this image of M7 (4.5 degrees above the horizon here) through the gaps between the blocks of flats, trees and streetlights, using a C102 on the mount that comes with it (not the most stable) and modded canon 1000D, ISO1600, 20 sec subs (the max that setup would tolerate). I had about 20 mins between obstructions, and think it was about 30 subs that were stacked from those I took (quite a few got streaked stars at 20s), with darks and bias, but no flats. [Not quite within the rules, but I think worth mentioning, is I have also captured Pluto, Triton and 4 of the Uranian moons with my 8SE on the altaz mount under the same LP conditions. Also extremely satisfying.]

I've got a wall-chart dating from (I think) the mid-70s, that was given away with the Daily Telegraph. When I got my 'new' edition of Norton, I gave away my old one to the daughter of the family who were then living next door, as she was very interested in astro.

Got one of these babies at the beginning of the year. Really jealous of your readings. I usually get down to about 18.5 - although, if I go inside and close the curtains I can get down to 22.1. So all I need to do is to work out how to get the sky into my lounge ... (probably easier than getting the streetlights switched off)

Another evening with the 6SE. One of the difficulties I have had is in getting objects anywhere near focus - there are fewer stars in the field and when they are out of focus they seem to be WAY out of focus, so decided to have some fun with Vega, which is bright enough to appear on the screen anyway. Discovered that I need to give the focus knob three 'rotates' to the left (from my 32mm e/p) when it is just the CCD. Maybe I should explain that a 'rotate' is, I would guess, about 60 degrees. It involves grabbing the focus knob with index finger and thumb, with the thumb in the (sort of) 10 o'clock position and rotating it a 'comfortable distance'. In some respects this is a very arbitrary amount, but experience has taught me that these turns tend to be about the same each time, so that is what I use. Anyway, having got the camera focussed on Vega I GOTO'd M57, and fine-focussed on one of the fainter stars there. I then proceeded to get about 45 min data (15 second subs). The resulting image is attached, and I am reasonably happy with it. When I get another clear night I intend to try and get some colour to add to it. Might do this using the bin2x2 function, as I have read elsewhere in the forum that that is ok for adding colour. Will have to do a bit of research before making that decision. Will also be interesting to see if I can get everything lined up using data from a second night.

Well it has been a while. Partly this is due to other new equipment that I have been 'getting to grips with'. Partly it is due to the frustration I was beginning to feel with the ccd and the seeming impossibility of me ever getting anything half-way decent. Anyway, I decided that last night would be an opportunity to have another go. Used the 6SE, as I wanted to image NGC 3242 (the ghost of Jupiter) before it completely disappears into the twilight for another year. Nice and bright, so thought it would not be a problem. First problem was the tracking. Because of the smaller fov, I found that, despite it being a better alt-az mount than the slt, fewer of the frames I took (which were only 15-second subs) were useable [due to trailing]; only 56/144. Well, 56 is better than none. However, when I put them in DSS, it told me that there were not enough stars to align and only one sub would be stacked. This is spite of the presence of at least a dozen quite bright stars. I tried numerous combinations, but could not get DSS to stack any more than one sub. Anyway, the result is attached. Horribly noisy, but this is hardly surpising in the circumstances. And even though it is only 15s data, the outer shell, inner structure and central star are all visible. So I suppose it could have been worse. And, in fairness, the problems I have had with it are due to the mount and DSS rather than getting to grips with the camera. So not too despondent.

Got out again on Sunday evening. Having read the manual, I discovered a setting in the software that automatically applies a stretch to the image you see (without affecting the original data). That made quite a difference!! Focussing was a beast. The camera takes continuous images and there is a counter that goes up as you get more in focus. I was using Sirius (nice and bright). However, the counter kept changing (sometimes quite dramatically) every time it took a new shot. Well, I did the best I could. Advice received on the forum (http://stargazerslounge.com/imaging-tips-tricks-techniques/134451-star-halos.html) was that I would be better off using a fainter star, higher up, with a longer exposure, so as not to be 'chasing the seeing'. That's one for next time. As a first object to image, I selected M50; reasonable size and fairly close by. The various shooting modes on the software are not necessarily that intuitive. For example, if I select 'continuous shooting', the number of frames I select is irrelevant, because it just keeps on going until I tell it to stop. If I select 'multiple exposures', it will take the number I have requested, but then add them all together (horribly noisy!). Or I can select the 'average multiple exposures' setting which still produces only one image from the number taken, but this time it is more like normal. But why would I do that?? Anyway, ended up with stars with halos; the suggestion being that it was probably a result of my focussing issue, so hopefully that will be put to bed with the new improved(!) procedure. However, as it is 'first light' for the camera, here (for what it is worth) is the result of combining 26 subs of 15, 20 and 30 second durations, totalling 9m 20s. UPDATE: Latest advice on forum seems to be that star halos are a result of unfocussed IR light, so I need to get a IR-cut filter. Ordered one from FLO, so will try again with that when it arrives.

Well, I put further testing on hold for a few days as I was involved in another project. However, got out on Friday (04/03/11) with the 102. Even with the focus tube fully extended, Sirius would not come to focus. Solution: a T2 extension ring from FLO fitted between the scope and the camera. Going to go for the biggest (40mm). Even with the filter wheel fitted (when I get round to that bit) the total increased distance will be less than the range of the focusser, so I should get maximum flexibility without running into difficulties of not having enough 'in-travel'. At least, that is the plan ...

Well, I've never done one of these before, so could be a disaster ... not that that has ever stopped me trying anything before:). Just starting with my first 'proper' ccd camera, so thought keeping a record of my experiences might be interesting, maybe even helpful to someone else embarking on the same journey. So, after the appalling conditions we have had for most of this month, I finally got out to give it an initial test run last night (24/02/11). Started off having problems getting my 102slt to work, so swapped to the 6se. As most of my imaging has been done with the 102 any comparisons are a bit academic, but I just wanted to 'have a go'. My thoughts before trying it were that the focus would be roughly the same as my canon, so plugged that in and centred Sirius. Then swapped cameras, and Sirius formed a donut roughly the size of the screen! What's that all about? Anyway, used the 'continuous shooting' mode to get the focus right. Then headed off to M41. Now I was aware that I would not get the entire cluster on the chip, but I have to say I was somewhat disappointed with the result. Even at 30 seconds, all I was getting was 3 faint stars. Even if I did not have the cluster totally centred (always a possibility) I was expecting more than that. Have not been able to find anything corresponding to an ISO setting yet, so maybe that was the problem. SO MUCH TO LEARN. I then decided to have a go at seeing 'the Pup', using an X-mask to produce some nice diffraction spikes. Well, I got the diffraction spikes, but no sign of the pup. All in all, a somewhat inauspicious start. But then, it is easy to forget how long it took to start getting reasonable results with any new piece of kit. You get used to it, and you begin to think that the next piece of kit will now be easy. Terrible forecast for tonight, but looks as if it might be clear again tomorrow night, so the plan will be to give it a go with the 102 and see if that produces better results.