Newbie please be gentle, I have a few questions

[Montana]

Father Christmas brought me a colour webcam yesterday, a PGR Blackfly colour cam so I can image the planets in colour.

I have never used a colour camera before and I have been watching lots of tutorials this afternoon and I have got very confused. I have a few questions

1. When imaging the planets I expected to image in colour but many videos say to switch debayer off? but I wanted to record in colour, I have a black & white webcam already so why should I switch the colour off?

2. In Firecapture there are lots of debayer settings not just one colour setting. Which do I use? there is a choice of 'Nearest Neighbour, linear,edge,smoothue,adaptive and VNG' also 'RG,GB,GR,BG' what do all these mean and what do you capture with?

3. Do you use avi or  ser?

4. Is there a step by step guide I could read showing exactly how to image a planet in colour and how to process? I have watched all the Planetary Imaging Youtube videos by wwgeb but he doesn't talk about colour cameras very much, it was just this passing comment on switching the colour off before recording but he didn't say why.

Kind regards

Alexandra

[Bizibilder]

Switching the debayer off simply means that the camera does not process (debayer) the image before downloading the data to your computer - thus allowing faster frame rates (everything else being equal).  You then run the debayer as the first part of image processing - most software has that function - you need to either find the cameras data to find which debayer to use or simply try them and you will soon see when you get it right! 

You can use avi or ser as preferred - ser is uncompressed as are many "versions" of avi (sorry don't know how to express that one any better!).

To start i would simply collect data in colour until you become familiar with your camera and software - then start to use the "bells and whistles" as you progress.

[JamesF]

A colour camera still images in mono, effectively.  It's just that the mono pixels have a colour mask in front of them to make them sensitive to only one of red, green or blue.  To get a full-colour image it's necessary to combine the readings of adjacent pixels to get the red, green and blue colours for each one.  This is the debayering (or demosaicking) process.  The reasoning for disabling the debayering on-camera is that it's often done using a fast algorithm that doesn't do the job as well as it can be done in post-processing.  You're not exactly "turning the colour off", just capturing the raw data from each pixel and delaying the debayering until you can do a better job later on.  AutoStakkert!2 can do the debayering for you when it stacks the image.

I wouldn't get Firecapture to debayer for you at all, except for perhaps when you're focusing which I find a little easier in "proper" colour.  "Nearest Neighbour" is probably adequate for that, but linear (or perhaps bilinear?) does a better job and isn't computationally too expensive.

The "RG", "GB" etc. refer to the pattern of the colour mask in front of the pixels.  If you take the first two pixels of the top line of the image, these letters refer to the colour mask they have.  The sensor will generally have every other pixel with a green colour mask in a chessboard pattern.  The remainder of the rows will then alternate between red and blue for the non-green pixels.  That is, the top row might be "red/green/red/green/red/green" etc. and the next row will be "green/blue/green/blue/green/blue", then back to the same pattern as for the first line and so on.

I think I would use SER for capture.  It uses more disk space, but AVI is a bit of a mess by comparison.  Lots of people do use AVI though, and if you are going to use it you need to make sure you have the UtVideo codec installed so you can use AVI files that don't do any lossy compression.

I did a walkthrough of a planetary capture at one point, I'm sure.  I'll post a link if I can find it again.

James

[JamesF]

Here's my post on processing: http://stargazerslounge.com/topic/184821-beginners-guide-to-stacking-planetary-images-with-autostakkert2/

Since I posted that I've gravitated more and more towards using SER for capture, but I think everything else is still the same.  I've not done much colour capture work recently though.

James

[JamesF]

Switching the debayer off simply means that the camera does not process (debayer) the image before downloading the data to your computer - thus allowing faster frame rates (everything else being equal).  You then run the debayer as the first part of image processing - most software has that function - you need to either find the cameras data to find which debayer to use or simply try them and you will soon see when you get it right! 

Good point, this. Trial and error does work fine for finding the right colour mask pattern.  If you have the wrong one you'll get weird colours and it's fairly obvious it's not right, especially if you try it during the day with the telescope pointed at some object you know the colour of.

James

[michael.h.f.wilkinson]

I always used the colour mode if the camera, rather than using software debayer, and that has always given me good results. Will try software debayer next time.

[Montana]

Thanks guys, that is a lot clearer now, I hate not understand the reason for things. I need to set my telescope up in the conservatory this afternoon and get the camera working on some trees as a guide. I don't want to get up at 5am on the only clear morning in the universe and find I have no idea what settings to use  

Alexandra

[Montana]

OK, so this afternoon I have had a practice on my local conifer tree and this is the result I get after stacking. Is it mean't to look like this? this is using nearest neighbour and GR??. I had to leave debayer ticked otherwise in ASK2 it still came up as black and white and the file was 250MB but if debayer was ticked in Firecapture then ASK2 saw it as colour and the file was 650MB size. So unticking debayer in FC seemed to loose data. Ticking ser was bad as ASK2 couldn't recognise the file. I can't imagine Jupiter would look very nice with all these squares???

I'm not sure whether I have missed something.  This is hard 

Alexandra

[Bizibilder]

Looks as if you are imaging through frosted glass!!    If you left debayer ticked then have you not debayered an already debayered image?

[JamesF]

That's genuinely weird.  I've never seen a result like that before.

I think I'd start with just FireCapture and forget the processing side for now.  Enable debayering in FC and see if you can get an image that looks correct in the preview.  Once you get that right, then disable the debayering.

James

[Montana]

What do you mean by debayering a debayered image? 

In the image window of Firecapture the image looks fine although the green tree seems to have a magenta edge to it. I leave debayer ticked in FC and recorded 100 frames of avi. I then took it into ASK2 and stacked the image (the window again shows colour) and the processed image comes out in these squares exactly where each alignment point box is?

Alexandra

[JamesF]

Ah, this could get confusing...

Some cameras can provide the raw image data or debayer the image themselves.  Others purely provide the raw data.  I don't know, but I suspect yours is probably the latter.  In that case I'm not sure Roger's question would apply as FireCapture would be doing the debayering.  Obviously if you have a camera providing a debayered RGB image and FireCapture thinks it's actually a raw image and debayering in software then something is going to get messy.

I wouldn't expect to see a magenta edge to the image, but that may just be an artefact of the debayering algorithm you're using.  "Nearest neighbour" is fast but not very good at handling edges and can make a bit of a mess of them.  You might find that the problem is reduced or even goes away if you choose one of the other algorithms, though you need a very fast computer to do stuff like VNG without losing frames.

If you're using AVI files, do you have the UtVideo codec installed?

James

[Montana]

Things get more weird, I have just tried using Flycapture software (PGRs own and very Rubbish).

Wow, the colour is perfect! it seems to record an avi using Nearest neighbour (I used all the default settings). I then process in ASK2 in exactly the same way as before, same alignment points and stack best 5% of 100. Then wavelet sharpened in Registax 6 as before and voila

So what is Firecapture doing?

Boy am I glad I am practising this now and not at 5am on Jupiter, I'd be hopping mad

Alexandra

[Space Cowboy]

Good to see you are venturing into the weird world of planetary imaging Alexandra!

I suspect your strange coloured image is a result of using the wrong bayer colour pattern in firecapture. If you click on the debayer tool icon and reveal the dropdown list there will be a selection of colour combinations i.e RG, GB etc. Try each one until the live view looks correct.

[Kokatha man]

...follow Stuart's advice in the post above to work out the RGGB or whatever...under "Debayer Options" in FireCapture check the first 2 boxes & this will give you a colour image preview - until you hit the capture button whereby the image turns mono. (RAW but with all the colour information encoded)

Do not use FireCapture to debayer...meaning you capture & record an avi in RAW which means the file-size will be much smaller as you found out...this is advantageous!

Record/capture as an avi - there is no advantage whatsoever recording planetary images in .ser! If you want any further proof it is because the amount of data, specifically dynamic range is still very limited even with the most colourful of planets in the Solar System  & you just don't need that many "bits" of information (.ser being 16 bit)  Feel free to check out our website & tell me where any of our images are "bit-poor" if you wish..! 16 bit .ser is just a waste of everything.

When you have your RAW avi after capturing - which you can play using Windows Media Player (but it will appear as a mono video) - you load it into AS!2 (AutoStakkert) & under "Color" at the top select "Auto Detect" & your frames will magically appear as the colour you first saw them as before hitting capture in FireCapture...

[michael.h.f.wilkinson]

SER can also be 8 bits, I have found in solar work. If 8 bit recording is ticked in FireCapture, SER or AVI doesn't make much difference, except that Windows knows how to do previews in AVI, but not in SER.

[Montana]

Thanks guys, I need another practice session i think

Kokatha man, do you have a link to your website?

Alexandra

[Kokatha man]

Thanks guys, I need another practice session i think

Kokatha man, do you have a link to your website?

Alexandra

Hi again Alexandra - I didn't mean to sound quite so strident but for me it's like "screen focus Vs Bahtinov masks" & "laser collimation Vs star-test collimation" etc & other hoary old questions that should've been put to rest years ago...

Here's the link http://momilika.net/  but my question was really rhetorical...you won't find any "bit-poor' images of our's (my wife & mine) because 8bits is more than enough...I haven't the very latest FireCapture version loaded but if I select 8bit I cannot create .ser files...& besides, as someone has said it's much easier for Windows to play avi's to check your capture recordings.

[Tyson M]

Great thread, I am taking notes as I will be the same boat as you Alexandra lol.  Got my alt/az EQ6 and ASI224MC ordered and coming in the next couple weeks. 

I have nothing to chime in, so Ill throw it something I came across in my search for planetary webcam imaging which I am not even sure is relevant. 

I've read that "nearest neighbor" is the algorithm that Registax 6 uses also, and is the reason why people prefer using Autostakker's algorithm . Registax only for wavelets. Not sure if that matters with image capturing between PGR's flycapture and Fire capture, if someone can expand on that, that would be great.

 Source: http://www.skyandtelescope.com/astronomy-resources/astrophotography-tips/redeeming-color-planetary-cameras/

Kokatha man, your work is stunning. I have seen in around in several places on the web .      An inspiration, indeed. Especially Uranus and Neptune. Best I've ever seen. Jaw-dropping. 

[Kokatha man]

...thanks Tyson - Uranus & Neptune are undoubtedly the greatest challenges in planetary imaging but I like to think our real forte is in imaging Saturn - as per images like this! http://momilika.net/WebPages/LatestSaturnPics_files/s2015-04-28_16-04_rrgb_dpmASI174MM.png - click on the image again for the full scale job.

It is true that the debayering in AS!2 is considered superior but that is only a small part of the story...personally I think the alignment capabilities of AS!2 are clearly superior & far less likely to have hiccups...but as you said Registax6 is still needed for wavelets applications!

Not really much to compare between Flycapture & FireCapture...FireCapture is a dedicated planetary image-capturing program & as such is a much-preferred software program for said applications than Flycap imho..!

[Montana]

I have finally done some more testing with the camera today.

This is with Flycapture - nearest neighbour and ticking debayer. The file is 650mb in size and Autostakkert2 recognises the colour in 'auto'

If I uncheck debayer, ASK2 doesn't recognise it in auto and I have to manually select RGGB and I get this result, otherwise 'auto' just processes a B&W version.

I then tried Firecapture again and I did manage to find the right setting, it needs to be 'Nearest Neigghbour and RG' and I get this result with debayer checked when recording (again 650mb file)

If however I uncheck debayer, the file is only 200mb in size, ASK2 does not recognise the colour, if you leave it in auto it is a B&W file, if you force debayer at RGGB then the result is this

So my conclusions are, for a PGR colour Blackfly do not follow the general advice by turning debayer off before capture, capture with debayer on otherwise 400mb of information is lost from the file and nothing will process properly.

At least I have learn't a very important lesson and not on Jupiter. I also know that my chip is RG (RGGB).

Thank you for the very useful tip on trying this out in daylight and not on Jupiter. 

Kind regards

Alexandra

[Kokatha man]

...apologies Alexandra - I didn't appreciate the full extent of your initial questions & only concentrated on the .avi Vs .ser question: you really should be checking/ticking both of the boxes at the top under Debayer in FireCapture for your recordings!

By doing this you will see your preview (ie, onscreen image before hitting the capture button) in full colour...but as soon as you hit the capture/record button the image will turn mono (b&w) for the duration of the capture - upon stopping the capture the image will return to the preview/full colour mode.

You do it this way to record in uncompressed RAW mode which is the best way to capture, also being smaller in size than capturing in colour modes...AS!2 will then correctly interpret the video which you have correctly identified as "RGGB" otherwise known as "RG" - AS!2 will do this if under "Color" in AS!2 you have selected "Auto Detect" of "Force RGGB"...

[Montana]

Thanks Kokatha man, unfortunately that is exactly what I did in FC and force RGGB ASK2 and the result was picture 4

Alexandra

[Kokatha man]

Thanks Kokatha man, unfortunately that is exactly what I did in FC and force RGGB ASK2 and the result was picture 4

Alexandra

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I don't understand your comments here Alex - this is what you said in your previous post in the text above "picture 4" - Quote: <"If however I uncheck debayer, the file is only 200mb in size, ASK2 does not recognise the colour, if you leave it in auto it is a B&W file, if you force debayer at RGGB then the result is this"> These comments state that you had these boxes I refer to UNchecked..?!?

I repeat again - you must CHECK (THAT MEANS TICKED! ) both boxes at the top in Debayer Options...only if the PGR Blackfy colour camera does NOT support Y800 would there be a problem although I would think that it does...but I could be wrong on that score.

[Montana]

I am confused now, I had this ticked. It was colour on screen but recorded a mono file. Is this what you call debayer off? The result was picture 4

Alexandra