Test with Steppenwolfs one shot colour ccd pacman neb

[CELESCOPE]

Having a word with Steve last night ,asked him how the one shot ccd SXVF H9C would perform over 20 min Subs, he said he had,nt pushed it that far before , being as i,m interested in maybe getting a one shot , he ran a 20 min sub for me ,and then sent the fits file to me , so i could do my own process.

I must admit i,m pretty impressed by just one sub of 20 mins , a few of these stacked would give a fine example i think , but even so this is a very good image for the time given,

So here it is

Thanks Steve for the loan of the sub

Rog

(click to enlarge)

[steppenwolf]

For a single sub, it came out pretty well didn't it! Now have we done enough to convince you that a one shot camera is no 'poor relation'

[CELESCOPE]

:lol,i,m certainly leaning towards one Steve for sure , just wait to see what comes out in the new year ,

[SteveL]

Go Roger! Join the happy band of us OSC imagers

[SteveL]

If you want an of my raws, just shout

[CELESCOPE]

thanks steve

[GazOC]

So much for colour cameras being inferior!!!

[MartinB]

Thought you weren't bothered about colour Rog

[CELESCOPE]

Now looky here Martin its not the top of my list for sure , but lets get serious now , 75% of mags , comps all like colour , so u have to go with the flow i guess, i would mainly use colour for the pretty ones anyway, and anyway , its my progress , ehehhehehehehe .

Still reckon a good B/W is better though,

Thats cus i,m old

Rog

:sunny: 8)

PS

HAVE YOU CHOPPED THAT DARN TREE DOWN YET HEHEHEHEH

[GazOC]

Are you saying theres not much (enough?) difference between one shot and LRGB to make it worth the trouble Rog?

[centroid]

Now have we done enough to convince you that a one shot camera is no 'poor relation'

I've never thought them to be so.

Having tried both LRGB and OSC, I am aware of the advantages and disadvantages of both, and at the 'end of the day' it comes down to personal choice.

Mono cameras are significantly more sensitive than OSC, and lend themselves much better to advanced filtering techniques, such a Ha. Also, LRGB is a much more scientific and skill demanding techique. On the negative side, it can be time consuming, which given the amount of clear sky opportunities we get in the UK, can be a problem. The results, however, as LRGB imagers have demonstrated, speak for themselves.

The biggest adavantage of the OSC camere, is it's ability to capture a full colour image in 'one go'. The disadvantage is the fact that it is significantly less sensitive than it's mono cousin. This means that to achieve the same SNR in the 'subs', the OSC requires significantly longer exposure times. Overall, however, the total time taken to obtain a full colour image, is significantly less than with LRGB. Although some imagers have used an Ha filter with an OSC camera, I think its fair to say, that the result is not as good as that achieved with a mono camera.

In my case, I went from OSC (MX7C) to LRGB (MX7 mono), and back to OSC (SXVF-H9C), so have experienced the merits and disadvantages of both sytems. For me, OSC is preferred option, based on the desire to image in full colour, within the restrictions imposed by the UK's weather conditions.

If I lived where I am at the moment, in Western Australia, where the number of clear nights would make us UK astronomers weep, I would probably opt for a mono camera and LRGB.

The 'bottom line', is the final colour image produced by OSC or LRGB, can be equally as good, except perhaps for the Ha content, where LRGB has the 'edge'.

So, as I said, its all down to personal choice, and I don't subscribe to the 'two camp' (LRGB v OSC) culture. We are all amateur astro imagers, with a common interest in trying to achieve the best we can.

Keep 'posting' those images, no matter how they were captured, whether you are an accomplished image, or complete novice.

Dave

[MartinB]

Guess it's a bit like anything else Dave, learning about the kit you have and playing to it's strengths.

No Rog, the tree is still there so no obsy for me

[CELESCOPE]

i think its down to personal choice , all i,m saying is , i was surprised at the out come of this image ,i would go for having two ccd camera,s one mono and one colour ccd , so i would have a choice , as i was saying i would use the colour one for the more colourful objects, i do go along with what Dave says though, just look at the weather here for the past 3 years anyway where its got worse and worse, , i cant stay up long imaging, having to be up before the birds start singing, so it only gives me a few hours ,so a good mono is the answer for really deep imaging , whilst a one shot colour gives me easier target satisfaction,

Its a fact i like two of everything , heheh , now wheres my other wife gone

Rog :rolleyes:

[steppenwolf]

Tricky one this - I gave very long and careful consideration to whether to buy a one-shot or a mono and filters but came to the same conclusion each time and this was down to a good friend of mine, Greg Parker. Greg has only ever used a one-shot CCD from his observatory in the new Forest and he (with help from Noel Carboni!) produces some of the best astro images around and these are all from the UK!! I decided that if a one-shot was good enough for him, it was good enough for me and although I am only at the start of the imaging learning curve, I hope to achieve images as good as his in the future.

With all the other problems we have to contend with whilst imaging - moisture, seeing, clouds, guiding, focus etc. - the additional complexity of taking different colour images seems to me to be a step too far in the UK. Even Ha is definitely within the grasp of the one-shot camera and I believe that the extra complication and time required to produce normal colour images using a mono camera does not yield a significant improvement in image quality over a one-shot camera. However, for false colour images using Ha, OII and SII I think that a mono CCD is king.If lived under un-polluted clear skies where I could be certain of an uninterrupted imaging session, I'd certainly give mono and filters a try but sadly, I am in the UK!

[centroid]

Guess it's a bit like anything else Dave, learning about the kit you have and playing to it's strengths.

I wouldn't argue with that one Martin , and you certainly demonstrate how you have 'played' to those strengths, in the quality of your images.

Just 'keep em' coming, as they are always a pleasure to look at.

Dave

[MartinB]

With all the other problems we have to contend with whilst imaging - moisture, seeing, clouds, guiding, focus etc. - the additional complexity of taking different colour images seems to me to be a step too far in the UK. Even Ha is definitely within the grasp of the one-shot camera and I believe that the extra complication and time required to produce normal colour images using a mono camera does not yield a significant improvement in image quality over a one-shot camera. However, for false colour images using Ha, OII and SII I think that a mono CCD is king.If lived under un-polluted clear skies where I could be certain of an uninterrupted imaging session, I'd certainly give mono and filters a try but sadly, I am in the UK!

Couldn't agree more - get a set up that best suits your location and situation. For me it's all about fast set up (sadly a non permanent one), fast scopes and sensitive cameras.

It would be interesting to do a comaprison of colour and mono H9 at a star party - same venue, same night. I now have a motorised filter wheel which has transformed my LRGB capturing. Typically I might go for 4 min lum unbinned and 1min RGB binned 2x2 - so a 7 min cycle which just runs automatically in maxim. So the comparison would be with a 7 min capture with OSC or a series of similar taken over a couple of hours. Of course, for anyone choosing a camera there is the small matter of a motorised filter wheel!! I have got into more scrapes with a manual filter wheel than I care to think about

What do you colourized folk do with the procssing? do you split into luminence and RGB or process all together?

[steppenwolf]

It would be interesting to do a comaprison of colour and mono H9 at a star party - same venue, same night.

That would be a fascinating comparison to make as although I am boldly shouting th case for OSC, I haven't tried LRGB to compare.

What do you colourized folk do with the procssing? do you split into luminence and RGB or process all together?

I take my raw FITS file, de-Bayer it at the highest quality with the RGB colour percentages set to what gave me a good daytime picture of my garden with an IR filter in line when I first got the CCD. I then stack the RGB images using either SUM or SD Mask. I then stretch the resulting RGB stacked image until I have a good 'start point' (sometimes using DDP), save it once as a FITS file (for security) and then (shame of all shame) save it as a .BMP file for final processing in PhotoShop. I have also added a luminance channel on the rare occasions that I have taken an Ha image but this is very rare indeed.

[centroid]

For me, its subtract a 'dark frame' (to remove any hot pixels), de-bayer, align and stack (add or average), de-convolve if required, DDP filter if required, and then over to P/shop for everything else.

When I had the MX7C, which uses CMY filters, I would split the subs into LRGB, and process the LRGB's separately, before re-combining them.

With the RGB filter used in the SXVF-H9C, I find that there's no benefit from doing this, so don't bother.

I always use an IR blocking filter, and all images are captured and processed in AA4.

Dave

[MartinB]

Thanks for the info Dave and Steve