groberts

Thanks vlaiv, seemed obvious but just thought I'd check. Graham

I routinely image with a CMOS camera (ZWO ASI1600mm-Cool) and calibrate with darks, flats and bias - recently switching to Dark Flats instead following various online advice. I now have some CCD data to process - having never processed CCD data I presume it's essentially the same but should I use bias or dark flats, or even both (which would seem unlikely)? Graham

In consideration of purchasing the new ZWO ASO294mm Pro camera I've been reading posts on various sites and there's frequent emphasis on the importance of ensuring that the native driver is used. What exactly is a native driver + would also be interested in first-hand experience of those using this camera with APT? Graham

Thanks - I've used bias with my ZWO ASI1600MM-Cool for over 4-years with no apparent probelms but with new filters + weight of advice in favour or using dark flats I thought I'd give it a try. Just completed my fist image here and all looks good, though whether bias would also have been OK I'll never know. It's just that bias was easier and quicker, though with the APT Flats Aid function the extra effort required is limited. Graham

Thanks all much appreciated. My problem with much longer exposures is (a) light pollution (b) aeroplanes (when they're flying) and (c) polar alignment and its impact on set-up + guiding etc. as I cannot see Polaris - my house is in the way! Can't do anything about light pollution except move = watch this space, make the most of the current lack of flights (I live between Gatwick - Heathrow airports + Redhill aerodrome down the road - of course I didn't do astronomy when I moved here!) Using PHD2 polar align routine + with the new multi-star guiding choice my guiding error is at last now looking very good. The 10-minute exposures this time worked out well + it cuts down data use, though still unsure about how to use the LRGB filters i.e. exposure times . I think more experimenting will help but overall the new filters are good. Graham

You can blame me: I purchased a set of Chroma filters last October and have been unable to image ever since due to the weather! At last in late February / early March I managed a few hours albeit at full moon, so for my 'first light' experience of these filters went narrowband. Whilst I'm happy with the attached Rosette image - certainly the 3nm SHO filters have improved the stars when compared with my previous ZWO filters - there were a few things: For the first time I went to 10 minute exposures as, I presume, the 3nm filters seemed to 'need' more light? I also did a quicky and dirty LRGB of M42 (not yet processed) to try out the other filters and was surprised to find the Luminance very overexposed at 180 seconds compared with the ZWO luminance filter using the same exposure & Unity settings. I would be interested to hear from others who use Chroma filters and their experience and thoughts on how to get the best from them e.g. I've always used the ZWO ASI1600MM Cool camera + ZWO filters at unity with good results but maybe the Chroma would benefit from higher gain etc.? Graham

Great images @Cobberwebb well done. I'm interested in a lightweight set-up like this and wondered: What tripod are you using? I have a Manfrotto 190 and would like to know if this is good enough to take the Star Aventurer? How + why are you using the mobile phone in the picture with the set-up? Your not guiding but presumably stacking the said 31 frames - what software have you used? Graham

I've been imaging for some time with a CMOS ZWO ASI1600MM Cool camera and have been mostly happy with the results. For calibration I've been using Darks + Bias + Flats registered and stacked in DSS but a while ago saw on SGL and elsewhere comments that with a CMOS camera it's better to use Dark Flats - better than what and why? I've therefore for the first time taken some dark flats (using previously calculated flats @ speeds for each filter but with the telescope cover on i.e. dark - right?). The questions I now have are: Is it good to use dark flats with CMOS cameras? How do I use the dark flats in the registering and stacking process? Do I just add them in together with the darks + bias + flats or do they replace one of these, bias perhaps? Any other guidance? Graham

After months of cloud we have clear skies & a full Moon! Notwithstanding, I have at last started to try out my new Chroma filters which I bought last year. Because of the Moon I've concentrated on narrowband but focus manually using a bahtinov mask (as I've always done previously with ZWO filters) with the Luminance filter - frankly I can barely see anything with NB filters to focus; in an ideal world I'd refocus with each filter. Anyhow attached are 6 x 10 min Ha 3nm exposures from last night and I wondered if this looks OK, not entirely sure what to expect? I use a cooled ZWO1600MM + WO GT81 and this image is without any calibration + RMS guiding error of +/- 1.10 + quick stretch i.e. not finessed. Whilst I appreciate longer exposures are always better, I would usually image at max 5-minutes or less because of numerous planes and helicopters - I live by Gatwick airport (not a problem at the moment) and my guiding though OK is never great as I have no sight of Polaris - my house is in the way. I would apprecate any thoughts or advice using these filters + aforesaid comment on this trial image. Graham

That looks really good on the wall Brendan, would be interesting to know the imaging details

I can see some of you are sucessfully using this lens with the Star Adventurer mount: How do you find this combination - with a DSLR, OSC or Mono camera? Would like to see pictures of the set-up if possible please? How does the mount handle the weight? I see the mount can go with a decent photography mount, I have manfrotto 190 - would this be up to the job? Where I'm going with this this to try and establish light weight set-up with the Samyang. I've been using mine with the AZ-EQ GT which is great but something more portable appeals. Graham

Been wanting to get this for some time, so rigged up my modded Canon 550D with the Nifty Fifty Canon lens and in between breaks in the cloud I was pleased to get this exciting image of Orion and all it's bits. I'd have liked some more integration but in the current weather condtions this was something of a gift as it started snowing towards the end! Graham Canon 550D modded Canon 50mm f1.8 lens AZ-EQ6GT mount - no guiding 42 x 120secs @ ISO 800 + full calibration

Sorry about above tripple post (senior moment!) - how can I delete the unwanted ones or please can the mods delete x2 for me? 😳

Thanks or this, I need to check but I think that is how I purchased it, so will certainly give it a try. Graham

Thanks or this, I need to check but I think that is how I purchased it, so will certainly give it a try. Graham

Thanks or this, I need to check but I think that is how I purchased it, so will certainly give it a try. Graham

Thanks all, much appreciated. Yes, such is the FOV of this lens that M78 & Barnard's Loop also crept in + it also deals so well with bright stars like Orion's belt. Graham

After literally months the clouds briefly relented this week over Surrey and I was able to get a couple of hours of Orion. Mindful of such imaging limitations in the UK and in the absence of a permanent observatory + inspired by others here on SGL, I purchased a Samyang 135 f2 last year but because of the said conditions it's use has been very limited so far. For the moment I'm using it with a modded Canon 550D, manual focus and no guiding - I was impressed with a few initial Cygnus images last year but this week put it to work on Orion and am blown away by it's capabalities. First, I really enjoy the widefield approach without resorting to mosaics - which would usually be impractical with imaging condtions here - thus producing interesting context of otherwise favourite targets imaged with a telescope. However, the quality this lens produces is quite extraordinary. Even though this was something of a 'quick & dirty' session + processing, looking closer at M42 (see cropped version) the detail and colour achieved by this lens far exceeds my expectations. I hope to match this with my mono CMOS camera & add guiding later this year but for now this little beauty is definately one of my star astronomy purchases. Graham Modded Canon 550D 56 x 120 sec = 1hr 52min No guiding Processed - PixInsight + Photoshop + Topaz Deniose AI

Thanks ngwillym , I was really hoping for something you could move around in real time by clicking on and moving but this is useful and for now has done the trick. 👍 Graham

I have the CCD Finder Rectangle function set-up for my equipment in CdC to provide an idea the the FOV/ framing for imaging. How can I rotate the said FOV or underlying sky view in order to match with the desired framing of the target with the FOV? Graham

No that's not happening - mine is v 1.8.5.703 bought a couple of years ago - is there a manual route to acces the update?

Already have AP v1.8 but can't find how to update - please direct?

Thanks Vlaiv, as I thought but just checking. Graham

In the absence of clear skies for some months, I have obtained subs and calibration frames from another party for processing but wanted to check a couple of points: There a darks at 25C and 15C - can these be processed together to produce a dark master or should the temperatures be processed separately? There are Flat_Darks, are these the same as Dark_Flats? I understand dark flats and have taken them myself at the corresponding time for the respective filter flats, but these are a all at 5sec, much longer exposures than I'd expect. The camera is a QSI683-WSG8. Graham

I was actually thinking of the data plans. Though not ideal, due to almost constant cloud cover now for months my astronomy hobby has ground to a halt and figured I could at least keep my interest going with such a plan + would provide good quality data of objects I can't see from home using better equipment. Thanks.