Beginners, monochrome is fastest and easiest!

[ollypenrice]

5 minutes ago, Macavity said:

Of importance (imo) is number of binary BITS used to represent the image.
What is the inherent "resolution" of the chip? How do the ADCs convert it into 
digital format? How is the information packed into "standard" data format etc.

If you are using colour (to some approximation) the available intensity levels
are divided by THREE. On the other hand, MONO data may only mean 12/14
bits (e.g. not 24!) Be aware of difference between "RAW" format and others?
How does YOUR software process the abvailable data e.g. 16 or 8-bit etc. 

 

Mono captures are 'purer' because every pixel value in every filter is measured. When OSC cameras are debayered the final pixel values are interpolated (a cycnic might say 'guessed'). If we imagine a continuous curve in an ionized hydrogen cloud, that curve will only be measured by the red pixels. There will be no continuity in that curve as it lands on the blue and the green pixels. There will be gaps in the measurement which must be filled in by educated guesswork on the part of the debayering software. As Craig Stark has explained, not all such software is equally good and there are different ways of carrying out the interpolation.

However, I haven't made this part of my pro-mono argument because I don't believe that, in practice, the consequences of interpolation versus true measurement really amount to much. I can't be sure that this doesn't lie behind my finding that OSC is sluggish to process but I don't think it does. I just think that luminance and Ha are very responsive to process.

Olly

[ollypenrice]

19 minutes ago, RayD said:

??

Ok maybe "OSC" was not a good example, but certainly I can take a JPEG image straight from my DSLR and open it in all it's colourful glory so how can mono therefore be easier?

Ah, I see what you mean.  If you shoot in JPEG your camera pops out a pre-stretched image? I don't know because, a) you shouldn't shoot in JPEG and b ) my own stacking programme, AstroArt, will give me an autostretch for saving any file format as a JPEG if I want it to. I do my two clicks to align and colour combine my RGB and there on the screen is an autostretch which I can adjust if I wish and save 'as is' as a JPEG. I can't see any difference between the systems other than that in my method I have, at least, captured, stacked and calibrated correctly in FITS format.

On a wider point, I think it would be crazy to base kit choices on what will be easiest for the first night of imaging without any regard to the fact that one will learn new skills quickly. It is easier to ride a tricycle than a bicycle for the first hour, maybe, but it soon becomes easier to ride a bicycle than a tricycle once you become more ambitious. (I would not want to ride a tricycle down Slack Hill in Derbyshire at 60 mph. It isn't too bad on a bicycle though. Just a bit bad!!)

Olly

[RayD]

5 minutes ago, Gina said:

I guess if you're prepared to put up with a thoroughly rotten image you could get away without processing by using JPG capture (sorry for swearing!!!) but I'm sure nobody would leave an astro photo unprocessed - the result would be so disappointing that it would put the majority of people off bothering to go any further.  Maybe it's a case of "beginners" or "absolute beginners" but absolute beginners would be better off forgetting about a telescope and just using the camera lens for widefield shots.

Agreed, but Mr Penrice specifically asked why no-one challenged his statement that mono is "easier", and now that I have I am presented with arguments about processing for better images, which I have already agreed are better with mono, which is why I shoot mono.

As I said, I can look at a colour image from my DSLR (in whatever format you want) with no processing at all, which I can't do with mono, so I fail to see how a "beginner" can possibly not find this easier? 

If the argument is that for a given quality of final image mono is easier, then no doubt it is, but there is then no comparison as the data collected from each is very different, so the result would never be the same in any case surely, but maybe i'm missing a point here?

[RayD]

26 minutes ago, ollypenrice said:

It is easier to ride a tricycle than a bicycle for the first hour, maybe, but it soon becomes easier to ride a bicycle than a tricycle once you become more ambitious.

Agreed, but I forget learning to ride a bicycle and think now that doing so is second nature, but now watching my Granddaughter learning tells me a different story.

It's very easy to use a DSLR for imaging but I'm sure those that do so and enjoy the results will obviously want better as we all do, will have to go to mono as it is undoubtedly the best, albeit to get images of the best quality raises the bar to another level of processing excellence which only experience can provide.

[ollypenrice]

2 minutes ago, RayD said:

Agreed, but Mr Penrice specifically asked why no-one challenged his statement that mono is "easier", and now that I have I am presented with arguments about processing for better images, which I have already agreed are better with mono, which is why I shoot mono.

As I said, I can look at a colour image from my DSLR (in whatever format you want) with no processing at all, which I can't do with mono, so I fail to see how a "beginner" can possibly not find this easier? 

If the argument is that for a given quality of final image mono is easier, then no doubt it is, but there is then no comparison as the data collected from each is very different, so the result would never be the same in any case surely, but maybe i'm missing a point here?

Well put and, yes, we have to put some kind of image standard on the table and say, 'This level of image: easier in mono or in OSC?' I think that the kind of image a beginner might want to be making within the first five nights would, counter intuitively, be easier to make from a mono camera. In expressing this opinion I'm not just giving my own point of view but incorporating into it what beginners have told me either about their own early experiences or about what they've discovered by getting started here with me.

Olly

[AKB]

37 minutes ago, ollypenrice said:

How about post-processing though? I always found OSC quite hard to process. It was OK on bright objects but was somehow sluggish to respond to post processing input. It just didn't seem to give much back. When I had both versions of the Atik 4000 I tended to use the OSC in conjunction with Ha captured in the mono. If I factor in this experience I still conclude that for a given result mono is easier.

Ah!  I always thought that was because I was rubbish at processing.  I have both mono and colour versions of SXL and ZWO cameras.  I think I'll set the OSCs to one side for this year and spend a while really practising my processing skills with a single channel (perhaps Ha?)  I must admit, that  when I first read this thread's title, I thought it would be about mono final images.  Any room for an AP version of Ansel Adams?  That's got to be easier than all this colour palaver.

 

[Knight of Clear Skies]

14 minutes ago, RayD said:

??

Ok maybe "OSC" was not a good example, but certainly I can take a JPEG image straight from my DSLR and open it in all it's colourful glory so how can mono therefore be easier?

This is true, but nearly all astrophotographers using a tracking mount are going to want to stack. I often find getting a reasonable initial colour balance very tricky, stacking modded DSLR data in DSS is a bit of a lottery. Sometimes I get something easy to work with, other times it's presented a thin vertical bar near the top of the histogram.

That said, I am thinking single subs are the way to go for some constellation shots. Here's a single 3 minute sub of the head of Draco with a 50mm lens:

This was very easy to process, just a quick colour balance (would have been even easier if I'd used an unmodded DSLR) and slight noise reduction - but I'm not trying to go deep here. A mosaic of a few shots like this would be a nice way to show some of the larger constellations.

I really must try a 1 minute blitz on various targets with my 135mm lens sometime.

[RayD]

I don't want anyone to get me wrong, I'm not challenging mono or saying imagining in mono is hard.  Having done it for a while now I find it very intuitive, and with an electric filter wheel etc. actually quite easy (it was no harder with the manual wheel, just a pain).  However, for a total beginner it is very easy for them to use their existing DSLR in the end of their OTA to just see if they like the concept of imaging, as it isn't everyone's cup of tea.

I actually champion mono 100%, and think the results "emerging" during processing is part of the attraction.

[ollypenrice]

2 minutes ago, AKB said:

Ah!  I always thought that was because I was rubbish at processing.  I have both mono and colour versions of SXL and ZWO cameras.  I think I'll set the OSCs to one side for this year and spend a while really practising my processing skills with a single channel (perhaps Ha?)  I must admit, that  when I first read this thread's title, I thought it would be about mono final images.  Any room for an AP version of Ansel Adams?  That's got to be easier than all this colour palaver.

 

If you want to get really great monochrome images with more than a touch of the Ansel Adams about them then you can do so and it will be considerably easier than any other kind of imaging bar none.  All you do is shoot 3nm Ha through an Astrodon filter onto a monochrome chip. You can do that in LP, you can do it significant moonlight (but not too close to full moon). The processing is child's play. All the difficult stuff - keeping the stars down, boosting the local contrasts, sharpening the details - comes ready made out of the filter.

Even after a couple of years with this filter I'll stretch an image, set the black point, look at it and think - is that it?  And you know what, it darned nearly is! It comes as close to the ready made high grade image as you will ever find in AP. You want evidence? Of course you do and here it is. This stacked and calibrated image was given two iterations of curves and then the black point was brought in to meet the start of the data line. Three operations and that is literally that.

Easy - but expensive.

 

Olly

[RayD]

2 minutes ago, ollypenrice said:

but expensive.

Wish I had £1 for every time I've seen or heard that since starting out in AP!!

[Astrith]

1 minute ago, ollypenrice said:

If you want to get really great monochrome images with more than a touch of the Ansel Adams about them then you can do so and it will be considerably easier than any other kind of imaging bar none.  All you do is shoot 3nm Ha through an Astrodon filter onto a monochrome chip. You can do that in LP, you can do it significant moonlight (but not too close to full moon). The processing is child's play. All the difficult stuff - keeping the stars down, boosting the local contrasts, sharpening the details - comes ready made out of the filter.

Even after a couple of years with this filter I'll stretch an image, set the black point, look at it and think - is that it?  And you know what, it darned nearly is! It comes as close to the ready made high grade image as you will ever find in AP. You want evidence? Of course you do and here it is. This stacked and calibrated image was given two iterations of curves and then the black point was brought in to meet the start of the data line. Three operations and that is literally that.

Easy - but expensive.

 

Olly

Its refreshing to hear its as easy as this......one step closer to buying a ZWO ASI 1600 mono ! A great image . Regards    Alan .

[Gina]

The ASI1600MM-Cool plus 3nm Ha filter really does make it easy.  30s subs (or maybe 60s for fainter DSOs) captured with APT and a camera lens with nice wide aperture (I'm using a 135mm f2.5 ex-SLR film camera lens - very cheap on fleabay) without guiding.  Calibrated with bias, dark and flat frames to clean up the image and a stack of a hundred or so light frames and you have a very presentable image   Even an uncalibrated single frame looks reasonable.

[ChrisLX200]

Do we ever get into any hobby just because it's 'easy'?  Dammit, if it gets any easier I'm going to have to look for another interest 

ChrisH

[Gina]

Maybe I should have said easier  

[Knight of Clear Skies]

I'm seeing little actual disagreement in this thread, it's mostly people providing complimentary views. This is constructive.  I ribbed Olly a little over the way he phrased his 'challenge' as it was like asking a dachshund to race a greyhound. In a straight race between OSC and mono, mono will win. Whereas 'how could a beginner most productively spend 2 hours imaging' is a different question with a host of factors to consider.

[CSM]

All very good but surely this is all way beyond beginners!  Equipment, expense, experience, clear skies, time - all needed in abundance. 

[AKB]

2 hours ago, ollypenrice said:

If you want to get really great monochrome images with more than a touch of the Ansel Adams about them then you can do so and it will be considerably easier than any other kind of imaging bar none.

Well this piqued my interest, and then I thought: "surely this very narrow-band stuff will mean much longer exposures?" which would bring all sorts of woes like tracking, guiding, meridian flip, ...

...is that true?  Asked in the spirit of:

24 minutes ago, CSM said:

All very good but surely this is all way beyond beginners! 

and

1 hour ago, Knight of Clear Skies said:

'how could a beginner most productively spend 2 hours imaging'

 

[alexbb]

7 minutes ago, AKB said:

Well this piqued my interest, and then I thought: "surely this very narrow-band stuff will mean much longer exposures?" which would bring all sorts of woes like tracking, guiding, meridian flip, ...

...is that true?  Asked in the spirit of:

and

 

Well, I agree that 30 minutes won't be too easy, but shorter and more exposures would work if they're not much shorter. On the other hand, the new CMOS mono cameras have a configurable gain and, above the unity gain, the idea (explained shortly) is that a photon should be recorded (wrt quantum efficiency). And because of the low read noise helped by cooling, you should be able to get to about the same result with more, but shorter exposures. Still mono sensor.

And there are piers (not tripods) on top of which the mount can be mounted and you could avoid maybe a little more the meridian flip, especially at higher latitudes.

[ollypenrice]

8 minutes ago, AKB said:

Well this piqued my interest, and then I thought: "surely this very narrow-band stuff will mean much longer exposures?" which would bring all sorts of woes like tracking, guiding, meridian flip, ...

...is that true?  Asked in the spirit of:

and

 

Curiously and, again counter intuitively, I find the 3nm Ha filter produces a better S/N ratio than the 7nm, if anything. It is blocking more of what you don't want, I suppose. NB does need long subs, optimally, but the tight filter is faster than the broad so far as I can tell.

Olly

[DaveS]

According to their figures a 3nm HII Astrodon filter will pass 95%+ of the wanted wavelength, so very little, if any, increase in exposure for the wanted wavelength, all the rest being suppressed.

For those of us in light polluted areas, NB allows us to capture longer subs if we wish, without LP washing everything out.

 

Edit: FWIW here is the relevant page from the Astrodon site. Make of it what you will

http://www.astrodon.com/store/p8/Astrodon_Narrowband_Filters.html

[Helen]

I love OSC!  There I said it!!    I started with a mono camera and just a Ha filter and learnt the basics of processing that way, and enjoyed it, but I wanted colour.  I tried colour filters and got frustrated - too many nights where I ended up with an incomplete set, or where one channel had a problem, focus differences meant an inability to run RBG sequences, or I had insufficient subs of each colour to get the noise levels down.   So I bought a OSC and a nice triplet and started enjoying imaging again.  A light pollution filter keeps background under control and colour balance is Ok - I run subs of 10 minutes.  I can get a usable image in a night, with the quality increasing with the amount of clear sky I get.  It works for me at the moment.  I get to post reasonable images on Facebook with explanations of the object, and I know that a lot of my friends and family enjoy this.  They are not mega-deep, and won't take enlargement and pixel-peeping, but I enjoy it.   I don't find processing a problem, but even it took longer then indoor time is a far less rare commodity than clear sky here! 

Helen

[Martin Meredith]

As an additional data point to show how easy mono is, live multispectral combination is now integrated into one of the packages some of us 'near-live' electronically-assisted observers use (StarlightLive, from fellow forum member Paul81), and an increasing number of us are opting for mono + filters, all controlled (filterwheel/aligned/combined) at the scope during the observing session.

For me this is the best of all worlds as in the same session I can choose to look at very faint galaxies/quasars in highly-sensitive mono, or apply RGB for clusters/planetaries/planets, or use narrowband for nebulae, or indeed take a spectrum. Colour balance is much better too in my experience. I've found that having a filter wheel has a bunch of other uses too (keeps dust off the camera, allows taking of darks without capping the camera/scope, stores the filters). The only downside is the expense, but with luck a filter wheel and filters are a one-off purchase.

Here's a few very brief captures from the same shortish session (clockwise from top left: NGC 6712, M11, NGC 410 group, M27 in O-III, M27 in H-alpha, M27 RGB; total exposure 14 mins for the lot). 8" f/4 Quattro + Lodestar X2 mono on AzEQ6 in alt-az mode.

Long live mono!

Martin 

[souls33k3r]

Why is OSC easier than Mono? Answer couldn't be any simpler

OSC = 3 alphabets

Mono = 4 alphabets

I rest my case your honour 

[ollypenrice]

47 minutes ago, Helen said:

I love OSC!  There I said it!!    I started with a mono camera and just a Ha filter and learnt the basics of processing that way, and enjoyed it, but I wanted colour.  I tried colour filters and got frustrated - too many nights where I ended up with an incomplete set, or where one channel had a problem, focus differences meant an inability to run RBG sequences, or I had insufficient subs of each colour to get the noise levels down.   So I bought a OSC and a nice triplet and started enjoying imaging again.  A light pollution filter keeps background under control and colour balance is Ok - I run subs of 10 minutes.  I can get a usable image in a night, with the quality increasing with the amount of clear sky I get.  It works for me at the moment.  I get to post reasonable images on Facebook with explanations of the object, and I know that a lot of my friends and family enjoy this.  They are not mega-deep, and won't take enlargement and pixel-peeping, but I enjoy it.   I don't find processing a problem, but even it took longer then indoor time is a far less rare commodity than clear sky here! 

Helen

I ain't saying you're not allowed to love it, Helen!

1 hour ago, souls33k3r said:

Why is OSC easier than Mono? Answer couldn't be any simpler

OSC = 3 alphabets

Mono = 4 alphabets

I rest my case your honour 

 

 If you want to write the golden word best you need four letters. It isn't easier to write it if you only have three!!!!

All good fun,

Olly

[souls33k3r]

lol, thought i should lighten up the mood in the room