I voted yes, but so is artistic licence. If you want to show true colours, colour balance is critical. If you want to show detail, maybe enhanced colour or narrowband monochrome is the way to go - both are extreme examples of artistic licence. Monochrome has been around for so long, that I bet a lot of people don't think of it as "artistic licence" - the colours certainly aren't true!
In terms of the basics of photography though, colour balance is up there with focus, composition, exposure, etc. So I see it as important, and then if you want to exercise your artistic licence after you've got the basics - go right ahead.
Sometimes a technically true image just doesn't cut it. If what you are after are the true colours then it has to!... but if you are after an aesthetic image, and even to highlight some detail, sometimes artistic licence helps. Example - last year I posted some views in the Blue Mountains. Mike commented on how green the country looked, so I fessed up. I had used the selective colour tool to add more yellow to the greens to give it a bit of kick. It made a drab drought photo look lush and appealing. The effect was what I wanted, it was obviously interpreted as I wanted, but technically the colours were not true and criticism of that would have been valid. It depends on the intended purpose of the photo... obviously colour correctness is very important in forensics, but for some forensic work enhanced colour is used to bring out details.
I know I'm a little off topic, but I see colour balance as a photographic basic to get right before before applying artistic licence, but I also admit sometimes some great pieces of art are the result of a mistake that's best left uncorrected.
Tak FSQ106N, SBig STL11000 and Tak NJP mount at my dark site observatory.
About 4 hours worth.
Gear I use now is FSQ106N (a dream come true scope - too easy to use)
Tak FS152 (6 inch) with field flattener and RCOS 12.5 inch (when its not windy) all on a Tak NJP mount (very easy to use, very accurate tracking, not many bells and whistles but its extremely fast to setup and get running accurately). Camera is an Sbig STL11000 class 2 with Astrodon filters and Baader narrowband. I also have a Starfish camera to be used as a guide camera and also planetary imaging.
I also imaged a lot with a Canon 20D which I modified myself and initially used a Nikon D70 which I also modified myself.
This may be relevant to the thread as the colour in this one isn't accurate most likely but chosen for effect as someone mentioned in the thread. I mean I like it, but others may go -oohh arrrgh- too pink.
Its O111 LRGB and I think some Ha in there ( I say I think as I switched filter sets during the imaging and one set may have been mislabelled).
I could reprocess it to make it more "natural" and it might be a fun exercise.
Obviously this thread has gone on and off topic a few times I think it's something to do with the first comment about people being too nice and not being critical enough
I try to be constructive if I'm going to be critical about an image. Other times I don't have time to respond in depth, so if the image is good "for them", then a simple "well done" helps to give encouragement and keep them going.
Anyway, that's the off-topic part.
On-topic, I think you're absolutely right Peter. I think the problem is that most of the DSLR imagers are quite new in what they do and so probably don't realise that the red is missing for a start, and that there *should* be red given the type of object and the emission it's producing.
You're right - the fix is easy and i'm glad you brought it up - it will give people a lot to think about. For some people, they might start to think more about *what* they're imaging and what the colour should be. For others, improving on what they've done before (regardless of accurate colour balance) is enough for them.
Even though you bring some contraversy with you at times, Peter, I enjoy your posts and your images and I hope that some of your knowledge can be passed along the way.
While it was on special the ST4000 was a pretty good buy. I can mention all the reasons why I still think this is so, but this is *totally* going off my original post..... I'd be happy to discuss that elsewhere.
The Tarantula nebula is not inherently blue or cyan. Unless you failed the Ishihara test, it would look red if you retina had cones that worked in the dark.
The fix, and I'm not talking about photometrically/pantone accurate dead nuts on colour, just a "shade" or two fix, is to simply use, well Iris, like Scott pointed out, or PS and simply adjust the red curve.
There is no law that says this is necessary, and sorry to harp on, but I suspect Canon would have a problem pedaling happy snap cameras that made skin-tones look green (unless Marvin the Martian is your best buddy)
i like marvin
but you cant just group all dslr's in the one basket Peter, especially with colour balance
Marvin is great. Arguably the most dedicated amateur out there. Bugger chopping a tree or two...he said...to Buggs I believe...and this may be not quite verbatim..
"Oh Dear Earth is blocking my view of Venus...I'll just have to get rid of it..."
Quote:
Originally Posted by h0ughy
i like marvin
but you cant just group all dslr's in the one basket Peter, especially with colour balance
I've got 3 DSLR's. No they are not the same. But they all make NGC2070 blue/cyan and skin tones, well, not like Marvin's.
Well said, Mike. I had a couple of goes at responding but the words just wouldn't work for me. You captured some of what I wanted to say but couldn't wordsmith in my post (hence I left that bit out!).
I'm a confessed "that's nice" feedbacker on a lot of astro images, too. If I feel I can add valid constructive criticism I will, but as a novice astro imager I don't feel confident to comment on colour balance of many astro images - because I just don't know. In the meantime, if I like an image I'll say so and offer encouragement. If I don't like an image, well I won't say so unless I can say why and do it in a constructive way.
I appreciate the constructive criticism of everyone's images, not just my own, because I can learn from that too...
How do you subtract the now strong IR componant in the image?
Do you use a IR filter as us CCDers do?
Howdy Jeff, with my camera I ordered the clear AR coated glass option rather then an IR cut filter that cuts in after the Ha line, as I want to dabble in IR photography. Ive also purchased an IR pass filter that blocks all visible light Here is an example of its use.
Its Planetary nebula MZ3, where the red has been assigned to the IR image, grenn to the red, and blue to the green. Its interesting how MZ3's central star appears yellow whereas no others do
Scott
Marvin is great. Arguably the most dedicated amateur out there. Bugger chopping a tree or two...he said...to Buggs I believe...and this may be not quite verbatim..
"Oh Dear Earth is blocking my view of Venus...I'll just have to get rid of it..."
I've got 3 DSLR's. No they are not the same. But they all make NGC2070 blue/cyan and skin tones, well, not like Marvin's.
ok well go back and have a good look at my initial post Peter. you will see the attached graph. You have avoided talking about modified DSLR's for some reason? if you are going to lump the colour balance discussion (and the reporting thereof on MelbMeadeScopes@yahoogroups.com by some members) then make it a balanced discussion.
I fully agree that most images are not right, so what? I admit that I frequently say "nice image" - just because that person or persons who posted the image need encouragement or maybe not to be discouraged from posting. They will find the day when they discover for themselves that their images are not good and have improved out of sight with subsequent attempts. Some just never get it right (i am in this group) and some just don't care. I would like to thank you for your posts, frank discussions and I do hope that you have recovered from that stray shot from Marvin- btw - one from a pentax from the lunar eclipse last year
I am happy to discuss the points you raise, but this is getting off the point of my original post quite a bit.
I had not idea my suggesting that NGC2070 is in fact , red, (and to argue just what shade, would be silly) would make it over to MMS, and have only responded there a few minutes ago.
It's late. How about a new thread specifically dealing with the points you raise is looked at later.
Quote:
Originally Posted by h0ughy
you will see the attached graph. You have avoided talking about modified DSLR's for some reason? if you are going to lump the colour balance discussion (and the reporting thereof on MelbMeadeScopes@yahoogroups.com by some members) then make it a balanced discussion....yada yada
if you are going to lump the colour balance discussion (and the reporting thereof on MelbMeadeScopes@yahoogroups.com by some members) then make it a balanced discussion.
I'm sorry this sentence makes no sense.
Is there an insinuation that by poking fun at you guys for getting your knickers in a twist that I did something wrong?
I was merely pointing out that the discussion may be of some interest to the many imagers in the MMS group, at all levels. I did it in the time honoured MMS way, by not taking it all that seriously. It states on the homepage of the MMS group "Warning: Aussie humour can lead to fedinkim drongo prangs "
So by saying that Peter had set the Cat amongst the Dobs, I thought most would get the humour. Just in case let me spell it out.
This is a play on words, parodying the saying "set the cat amongst the pigeons" meaning to cause a stir. Most of the Meade group have or have had in the past a Meade GOTO SCT (or catadiatropic scope, Cat). A lot of the IIS group have Dobsonian mounted Newtonian reflectors (Dobs). Peter Ward has a selection of scopes including an RC (a type of Cat), hence he had set the Cat amongst the Dobs.
I'm sorry but if you find that offensive in some way, don't read it, or contribute to the discussion in THAT forum, not this one.
I am happy to discuss the points you raise, but this is getting off the point of my original post quite a bit.
I had not idea my suggesting that NGC2070 is in fact , red, (and to argue just what shade, would be silly) would make it over to MMS, and have only responded there a few minutes ago.
It's late. How about a new thread specifically dealing with the points you raise is looked at later.
That would be great
Perhaps you might like to explain how one may "ramp up the red channel" for those in the novice class with Photoshop. Some may not fully understand the term?
I personally struggle with the IR component having a modded DSLR, take M45 for example, I have seen and indeed butchered the colour balance of that object. I am happy to send the fits/tiff/jpeg file to you to see how you balance that
Rat156 I hope your NB images go well as for the postings - where ever you feel most welcome Peter's comments have been educational and yet at the same time interpreted in a terse manner. Peter seems to have that abrasive touch , yet somehow conveys a message. It’s the abrasive touch that rubs up some people. We are a diverse mob, but sometimes the gene pool does narrow, no matter what the band
I don't see excessive red there at all, as there is a bit of background red in the nebula of M45.
The usual heavy red from a modded camera requires the custom white balance I mentioned in the earlier email or using colour processing and pulling back the red a lot.
In your M45 image the black though is a bit too black - so some data has been "clipped" and this also includes some of the fainter nebula. I used to do this all the time.
A good read on Photoshop is Wodaski's Zone System. Goes over everything.
Howdy Greg, my actual 350D was bought new and modded from Hutech with the clear AR coated glass option, my IR pass filter I got off Ebay, some links here http://search.ebay.com/search/search...ter&category0=
Mines a 58mm which suites my Canon kit lens, I bought separately a stepdown ring from a local photo store so I can fit it to my 50mm f1.8 lens. Yes I can shoot IR hand held in daylight with fast enough shutter speeds. Mind you a 40D would be better with its live view. With my 350D I have to take pics then check focus by trial and error.
Normally a 58mm filter is too big for a 2 inch focuser but it will fit in behind mine so I can use it in my telescope.
My filter is 850 nm cutoff
First shots here http://www.iceinspace.com.au/forum/s...ight=infra+red
Scott
The new Canon 40D seems to be a lot more sensitive to the red than any other camera I have seen used and also has a 14 bit converter
I have been thinking about getting a Canon 40D recently as it is such a leap forward for DSLRs. Probably the first major improvement over the venerable 350D.
Greg.
Curious as to whether this camera gives much more of the reds rather than the cyan colours previously discussed.
The real problem here folks is that a DSLR is designed to give an image that closely represents the 'average' human eye's spectral sensitivity to any object illuminated by daylight. There is an adjustment for artificial light by allowing for colour balance or by auto white balance and other more complicated methods. But this is marginal compared to astro images.
We barely perceive H Alpha and so a unmodded DSLR does not either. I think that is what Peter was trying to point out. Hands up those who did not know that? Ok.
David Malin pioneered careful use of RGB filters with black and white film and then by a colour process which was the opposite of colour separation as in movie film as in the earliest colour movies. He used to put together 'colour' images of many nebs etc.
The problem has always been H Alpha, what colour is it? As only our scotopic (night) vision barely has a chance to perceive it and even then it is in black and white or grey tones!
The argument is basically about assigning what colour that the parts of the EM spectrum we can't perceive.
I personally like a 'normal' colour assignment to various spectral emission lines as in O3, Hb, SiII, and Ha.
Where the problem really is that modern CCD's with no filtration are really good at a far wider spectral sensitivity than the human eye. If you could buy a DSLR without a Bayer Matrix Filter and the filter in front of the sensor end of argument. Then just treat like the DSLR as an astro CCD. Unfortunately this is not the case. So we make do with the so called shortcomings because of the cost factor. One good thing is that the Bayer Matrix filters are essentially transparent to HA and IR, this is more correct for the 'red' Bayer filters.
Colour balance has no relevance in astro imaging as the spectral width of the incoming light from stellar nebs etc is far greater even accounting for atmospheric absorption and scattering than our spectral perception.
To me it is a non issue. For one simple reason. We can record a signal and then produce an image from it. Do we throw away any signal that we cannot normally see? No just incorporate it into the final image. I do not care if it looks too red!
As a person who took their first shot of the Moon just two nights ago I don't have any technical background concerning how the colour balance is altered or how it differs with different equipment, but I think there are some points that are probably quite basic if you are talking about images as percieved by the human eye.
If you were to take an infrared image of an object, how do you get the colour balance correct? The only "reasonable" answer would be totally black as this would be the perception seen by the eye.
If you take an image in the visible band with an imager that is lacking in sensitivity in one area, say red, should you push the red to the point that it makes up for the imbalance? The image, after all, is a "true representation" of what the imaging equipment saw (more or less).
Because we don't really perceive colour in most objects, it is difficult to really decide what is correct. I guess we go by what we see in books and therefore what we expect to see.
I think that unless you are performing some observation for scientific analysis, the correct colour balance is the one that creates a pleasing result. Unfortunately, it is all very subjective. Of course if you took a shot of M42 and "deleted" the red channel, you would get a result that most people would say was "wrong" (including me). If it looks "natural" then you can't be too far wrong. If it looks like you have been tripping out on LSD, you probably have it wrong!
...but did we get away with it?
I think it's something to do with the first comment about people being too nice and not being critical enough 
.
