Colour or Monochrome for UK

[r3i]

cheap OSC to cut your teeth on (easier to sell on, and overall better than DSLR as you have to learn more "How to")

If you get it to all work then Mono when you have it all working with reliability night after night.

That sums up my situation nicely - I still need get my whole system working reliably before I can justify the investment in a mono + filter wheel + filters.

You want a mono camera for 1 huge reason : Narrowband imaging.

NB imaging is the great equalizer when it comes to elminate LP effect. Because you are shooting in a 3,5 or 7nm range, It doesn't matter whether you image in downtown london or in the country. I've done OSC imaging before and yes the rewards are faster but you have to deal with a lot more noise.

Yes - that is where I want to get to eventually.

[steppenwolf]

What happens when (as is reccomended ) when you bin the colour in a mono camera???? You loose the resolution, back to what a OSC does.

It doesn't matter that the colour resolution is reduced with binning as it is only overlaid on the fine detail of the luminance channel. Try this enlightening experiment:-

Take any colour image and copy and paste it into a new data file. Now convert the new image to greyscale. Copy and paste this greyscale image on top of the original colour image and set the blending mode to 'Luminance'. It looks like nothing has changed - prove this by selecting and then de-selecting the luminance layer so it is visible/invisible. Leaving the luminance layer invisible, select the colour layer and then seriously blur it using Gaussian blur - the image looks pretty dire now! BUT now make the luminance layer visible again and note what happens!

The resolution/fidelity of the colour image is not important, the detail is held in the luminance channel.

[PARTY MARTY]

I just can't believe that there is a war going between the debate of a OSC and Mono CCD'S still!

I did this boasting about my QHY8L on one last thread on SGL, And I was shot down in flames that I was talking complete nonsense!

Now I have more knowledge about CCD's now and stop being big headed about it!!, I have seen the results of a mono and I have to say that I'm really impressed by the sheer detail mono gives due to the Lumiance filter, I love my QHY8L is a really good OSC don't get me wrong, but the OSC will be my travel CCD which I would take with my Lunt 80mm ED Refractor with me on holiday to darker sites! Easy to set-up and you're away collecting data!

However the Mono offers more, OK not as straight forward as OSC but you can image in light polluted skies, even if the moon is up, using broadband filters will help, and the lumiance filter if you combine it with the RGB frames will reveal hidden finer detail , however Mono is more senstive than a OSC of the same chip size and I now know how the Bayer matrix works which I see why the OSC is less senstive!

However no matter what CCD you own, if you want stunning images, I'm afraid you still need collect data from night by night, and collect progressively, I realised that one I made 20 x 300 seconds of the Horse head and Flame nebula and stacked them in DSS and processed in Paintshop PRO X5, And believe me it was bearly visible with slight hint of red in the nebula , but the next night I collected more data, further more 20 x 300 seconds and 15 x 600 seconds, thrown in some darks, flats and bais, processed again and BOOOOMMMM!!! The image was much better, less grainy, more colour, much sharper than the last image I processed, Again my image still looked as it needed more work, So it's capturing more data! As you see I notice a lot the more stunning images done by experinced imagers, they are have done many nights to achieve exposures of 5, 6, 7, 8, and 24 hours of light frames gathered to produce fantastic images, so as you see it's all about collecting as much images as you can get and a heck of load of processing which is another black art in itself!!! The processing is a big learning curve yet again!!!

Regardless of which is better! Both are fantastic CCD's, Being a beginner myself I did start imaging with OSC to begin with, which I believe is not a mistake I made, in fact if I started at the deep end at mono ccd I probraly wouldn't have taken CCD imaging at all, But for me starting with a OSC at the begining and capturing fantastic images for the first time and getting to know how things work with auto guiding Etc etc and steadily work my head around the equipment, don't forget that imaging is huge astronomy topic as it is, It was quite a steep learning curve for me, And if I was to get furstrated with it and decided to get rid of my OSC, I would have not waste much money in the process.

However Mono CCD I would go for next challange, And I will be getting the QHY 9 mono with the filter set and 2" LRGB and maybe I'll throw in the Hydrogen alpha as well, as this is quite advanced imaging and a very expensive hobby indeed but going mono means you're not limited to what you can do in Astro-photography!!!

[Tim]

Not sure if it got answered, but somebody asked why mono is better for Moony nights. Just that you can still image to great effect with narrowband Ha or Sii filters even under (not right next to) a bright full moon and still get acceptable results. You can also extend a narrowband session into astro twilight with narrowband filters, and hence they are more useful in the summer months when the hours of true astro darkness are very limited.

Again it's not a question of which camera is best, more 'which one is best for you?' given the situations outlined above.

I'm hoping that one day I will be in a position to take say 10 hours of Luminance data on a target, then swap to a matching chip size OSC and take a few hours of colour data and then merge the two together. It has worked quite well with images of a different scale, so I am hopeful that the matched chips would yield a better result again. Somebody please tell me if I am misguided here

[lensman57]

It doesn't matter that the colour resolution is reduced with binning as it is only overlaid on the fine detail of the luminance channel. Try this enlightening experiment:-

Take any colour image and copy and paste it into a new data file. Now convert the new image to greyscale. Copy and paste this greyscale image on top of the original colour image and set the blending mode to 'Luminance'. It looks like nothing has changed - prove this by selecting and then de-selecting the luminance layer so it is visible/invisible. Leaving the luminance layer invisible, select the colour layer and then seriously blur it using Gaussian blur - the image looks pretty dire now! BUT now make the luminance layer visible again and note what happens!

The resolution/fidelity of the colour image is not important, the detail is held in the luminance channel.

Hi,

If funds were no object, I would buy two cameras with the "same" chip, one in mono and the other OSC, I would mount them side by side on two identical scopes and align them. I would then image in RGB and Luminance simultaneously and then combine them post capture. When is the lottery draw please?

[laser_jock99]

I love my ATIK 460 colour because it makes imaging enjoyable. My husband loves my ATIK 460c because it makes my imaging enjoyable!!!

I live in wet Wales and I have quite a few trees around so I don't often have the luxury of taking long image runs over a night or many nights. I tried mono for colour and it frustrated me as I rarely managed to get enough subs of each colour to get the noise levels low enough for a good result. Now I can get a nice colour result in a night that will not win any prizes but gives me satisfaction and allows me to show friends and relatives some wonders of the night sky (most haven't seen Olly's or Tim's images so don't know know how much smoother/sharper a result it is possible to get!!).

I know that when I can get more data I can improve iteratively the quality of the shot, but at least I've got something to build on :-)

Moonlight is an issue though, and some targets need the extra definition that Ha can provide.... so I must admit I've bought a mono version too. But ask me just to keep one and it would be a complete no-brainer for me - OSC just for the fun of it

Helen

Good points - if you can get results YOU are happy with and you can see that YOUR work is improving- then maybe sticking with the OSC is better for your sanity? None of us want our imaging to became a tedious 'chore' that we don't look forward to. Presently I find working with DSLR's a challenge enough in my limited imaging time. One day I guess I'll 'upgrade' to CCD but I have enough to keep me busy for the moment!

[steppenwolf]

If funds were no object, I would buy two cameras with the "same" chip, one in mono and the other OSC, I would mount them side by side on two identical scopes and align them. I would then image in RGB and Luminance simultaneously and then combine them post capture.

I do this currently but with non-matching CCDs and telescopes and it works just fine.

[Sp@ce_d]

I was wondering how long it would take for the dual shooters option to rear it's head. Works quite well for me using the 1000D & 314 & has meant being able to get enough data for at least some presentable images that I probably wouldn't have achieved otherwise, given the atrocious lack of clear skies this last winter. I do love the quietness of the Sony chipped 314 though & if i had to choose only one it would still be the mono with filters. I will probably replace the DSLR and try a OSC CCD when funds allow though as I find there's a lot of chrominance noise to process out.

[lensman57]

I was wondering how long it would take for the dual shooters option to rear it's head. Works quite well for me using the 1000D & 314 & has meant being able to get enough data for at least some presentable images that I probably wouldn't have achieved otherwise, given the atrocious lack of clear skies this last winter. I do love the quietness of the Sony chipped 314 though & if i had to choose only one it would still be the mono with filters. I will probably replace the DSLR and try a OSC CCD when funds allow though as I find there's a lot of chrominance noise to process out.

Hi,

I think a shoot out is in order now. If someone does have both a mono and OSC and would like to take this task up then the results would probably speak more than a thousand posts.

Regards,

A.G

[reddoss]

I know that one argument for mono LRGB over OSC is that you can get a lot of data to boost an image in a fairly short time with the L channel. However, with my OSC images I use the false L channel method (i.e. a mono chrome image of the nearly completely processed image) in PS processing and then just blend the two together using the luminosity mode.

Also I think that the mono LRGB v OSC argument is rather like those of PC v apple Mac, or BMW v Merc, Ford v Vaxhall etc etc. In truth each system has its pros and cons and in the end it's down to one's own personal preference and circumstances.

Last year I made the transition from moded DSLR to OSC and really appreciate the difference. I am going to stick with it as A) I have no observatory and the LP is very bad where I live, so I have to set up in the field in a dark(ish) sky site. I live below the jet stream C) I do not have the patience wait for months to collect all the LRGB channels if you can not get all four in one session. D) Also I think I would find having to re-focus for each filter rather tedious.

I have nothing against mono LRGB. I just think it is a system that was probably developed in countries with large stable air masses, unlike the UK.

[Fogboundturtle]

I know that one argument for mono LRGB over OSC is that you can get a lot of data to boost an image in a fairly short time with the L channel. However, with my OSC images I use the false L channel method (i.e. a mono chrome image of the nearly completely processed image) in PS processing and then just blend the two together using the luminosity mode.

Also I think that the mono LRGB v OSC argument is rather like those of PC v apple Mac, or BMW v Merc, Ford v Vaxhall etc etc. In truth each system has its pros and cons and in the end it's down to one's own personal preference and circumstances.

Last year I made the transition from moded DSLR to OSC and really appreciate the difference. I am going to stick with it as A) I have no observatory and the LP is very bad where I live, so I have to set up in the field in a dark(ish) sky site. I live below the jet stream C) I do not have the patience wait for months to collect all the LRGB channels if you can not get all four in one session. D) Also I think I would find having to re-focus for each filter rather tedious.

I have nothing against mono LRGB. I just think it is a system that was probably developed in countries with large stable air masses, unlike the UK.

first of all, You don't have to re-focus for each filter because you can buy them parfocal ! 2nd, you can automate with an Electronic FW your whole session.. the sensitivy of the mono compare to OSC will allow you to gather more data in the same amount of exposure with less noise.

I live in BC, Canada. We have about 15 clear night a year and I live in an orange zone. Mono camera allows me to do NB imaging. that means I am not bother by light polution one bit

[x6gas]

Bit harsh to characterize this discussion as a war ... I think it's been very insightful.

I still remain to be convinced that you can capture more photons with a mono camera + filters than a OSC in any given time, but there are clearly pros and cons to both.

I find that - for the reasons mentioned elsewhere regarding LP and the ability to shoot narrowband on nights with a relatively full moon - a mono camera is the only way for me. I'm a narrowband junkie now, anyway...

I have a side-by-side rig now (not that it has been used in anger) but I will be using that to shoot luminance with one camera and RGB on the other or two narrowband filters at the same time. Wouldn't rule out a OSC instead though...

[Zakalwe]

OK, take an hour in an OSC and an hour in mono using RGB filters.

OSC; for an hour a quarter of the pixels collect blue, a quarter collect red and half collect green.

RGB; for 20 minutes all the pixels collect red, for a second 20 minutes they all collect green and for a third 20 minutes they all collect blue.

It would be easier to make the point if OSC Bayer Matrices were a third red a third green and a third bue, so pretend for a sec that they are! If you do this you can see that the same number of red photons will have been captured by both cameras. Ditto the two other colours. So far as I can see there is no difference between collecting the colour filtered photons continously using a third of the pixels for all of the time or all of the pixels a third of the time in turn.

Its such an interesting debate, for sure!

I assume that you are comparing a mono version of the same chip with a OSC version in the above, Olly?

Another way of looking at it would be to compare what you can get for the same budget. I recently bought a 428, filterwheel and LRGB filters. They cost just under £2k. For that I get a 1932x1453 pixel chip. For an extra £60 I could have opted for a OSC 460Ex with a 2750x2200 pixel chip (thats twice the size). or for an extra £200 I could have gotten an OSC 490 with 3380x2704 pixel sensor.

I could still do narrowband with the OSC. Yes, only one in 4 pixels would collect data and yes the resolution would have been less than the same sensor in mono. The question is would NB with a 490 be any difference than NB with a 428?

confused.com :huh:

[lensman57]

Its such an interesting debate, for sure!

I assume that you are comparing a mono version of the same chip with a OSC version in the above, Olly?

Another way of looking at it would be to compare what you can get for the same budget. I recently bought a 428, filterwheel and LRGB filters. They cost just under £2k. For that I get a 1932x1453 pixel chip. For an extra £60 I could have opted for a OSC 460Ex with a 2750x2200 pixel chip (thats twice the size). or for an extra £200 I could have gotten an OSC 490 with 3380x2704 pixel sensor.

I could still do narrowband with the OSC. Yes, only one in 4 pixels would collect data and yes the resolution would have been less than the same sensor in mono. The question is would NB with a 490 be any difference than NB with a 428?

confused.com :huh:

Hi,

Just imagine for a moment if Canon or Nikon decided to relase a small batch of their 36 Mega pixel DSLRs without the UV/ IR and anti aliasing filter for Astro imagers. WE would end up paying about £2500.00 for a state of the art low noise, high sensitivity full frame chip with over 9 Mega pixel of each R,G and B and the Lum could be extracted from the mono . Now that would be interesting I think.

Regards,

A.G

[Fogboundturtle]

Hi,

Just imagine for a moment if Canon or Nikon decided to relase a small batch of their 36 Mega pixel DSLRs without the UV/ IR and anti aliasing filter for Astro imagers. WE would end up paying about £2500.00 for a state of the art low noise, high sensitivity full frame chip with over 9 Mega pixel of each R,G and B and the Lum could be extracted from the mono . Now that would be interesting I think.

Regards,

A.G

That wouldn't remove noise generated by the bayer matrix and the lack of cooling. CMOS are still not close to the QE of CCD chips on the market.

[ollypenrice]

Hi,

I think a shoot out is in order now. If someone does have both a mono and OSC and would like to take this task up then the results would probably speak more than a thousand posts.

Regards,

A.G

I've done this for Astronomy Now. I did 5.5 hours in the same scope using Atik 4000 mono and then OSC on M42. I concluded that there wasn't much difference and published both images side by side. There isn't much difference. I can't publish them here because they were for the magazine but do trust me. On the back of this I bought the OSC that I had on test.

More experience over the next three years refined my view. The OSC is sometiles as good as the mono, sometimes not as good and it is never better. It really does depend on the target. The ability to add Ha from a mono is sometimes a game changer, too. For all this, I stress that I loved the OSC.

As for binning colour, I don't recommend it. I recommend the opposite for various reasons but it remains an option if time is short.

As you can see from the above, I was comparing chip with chip. I don't think all chips respond equivalently to the Bayer Matrix, either. One to avoid, based on what I've seen here and the comments of its experienced owner, is the OSC 8300. His view was 'sluggish' and no better than his DSLR. Maybe at very fast F ratios, OK.

I dithered over our latest camera. We will probably have a loaned FSQ106/Atik 11000 tandemed with our own FSQ106/11000 quite soon. I could have gone for an OSC but I thought, no, even with a tandem I want the flexibility of mono. A bit of moonlight, two FSQ's pulling in Ha. Gimme gimme...

Olly

[Zakalwe]

two FSQ's pulling in Ha. Gimme gimme...

[ollypenrice]

He can afford a dozen!

Olly

[Zakalwe]

He can afford a dozen!

Olly

Takahashi WASP?

(feeling weak at the knees)

[turbolord]

I don't debate that Mono camera have better spacial resolution but from a signal to noise point of view the answer is more complex. If you had a white light source illuminating the camera then the light reaching the mono pixels is set by the bandwidth of the filter that is used. The Colour camera pixels receive the same number of photons as the mono pixels (assuming the bayer filter transmission is similar to the filter on the mono camera) Since the camera is the same, the pixel S/N is the same. What really makes the difference is the Luminance channel gets up to 3 times as many photons giving you up to 4.7dB advantage on the L channel (Only for a white light source).

For Narrowband imaging then again the signal to noise in the red pixels is slightly reduced (due to the loss of the bayer red filter and the H-alpha filter) but I expect this to be no more than 5-10%. The big addition of noise is that the green and clue channels now only have noise so the interpolation algorithms will I think merge the dark noise from the other channels into the red. Though haw much this occurs is dependant on the algorithm. Craig Stark did a great paper on Debayering techniques (http://www.stark-labs.com/craig/resources/Articles-&-Reviews/Debayering_API.pdf )

On multi-line nebulas the noise will be reduced on the colour camera as the green and blue channels will have information within them.

[lensman57]

Hi,

Well, I bought a very well used Atik 16LC for the price of a middle of the road planetary colour camera. Why a mono? In the last few weeks all my attempts at DSO imaging have turned out not to show much colour even using a modded 1000d. So Monochrome it is. Now just have to hope that it runs on my Win 7 64 laptop and get used to the tiny sensor.

Regards,

A.G

[Gonzo]

I don't think it matters much mono or OSC, have you seen the weather???

[lensman57]

I don't think it matters much mono or OSC, have you seen the weather???

Agreed, 100%.

A.G

[sloz1664]

Hi,

Well, I bought a very well used Atik 16LC for the price of a middle of the road planetary colour camera. Why a mono? In the last few weeks all my attempts at DSO imaging have turned out not to show much colour even using a modded 1000d. So Monochrome it is. Now just have to hope that it runs on my Win 7 64 laptop and get used to the tiny sensor.

Regards,

A.G

I hope that's the one I pointed out to you :rolleyes:

cheers

steve

[lensman57]

I hope that's the one I pointed out to you :rolleyes:

cheers

steve

Hi Steve,

With regret not. The chap had sold it and not taken it off the list. I got one with the smaller chip, 424 I think, at less than 1/2 price he was asking for. Many thanks again for pointing it out. Now I have to try and use the filter wheel that I bought a while back.

Regards,

A.G