OSC camera vs DSLR modified.

[Marvaz]

Hello.

I've live in light polluted area ( Watford Hertfordshire). I'm using modified Canon 1000d. Just wondering to move for Osc camera ( Qhy8l with Idas filter. I know that the best solution will be mono and narrowband imaging but it's not really for me. Not now. Do you think these move is reasonable or is totally pointless?

Willbe grateful for yyour opinions.

Marek.

[RikM]

The increase is sensitivity and reduction in noise with a CCD camera compared to a DSLR is considerable. Personally I prefer Mono and filters because it is faster but a OSC CCD should still be a meaning full step up if you don't want to go all the way.

[jambouk]

When i refer to ccd i mean OSC camera; dslr = dslr....

Ccd will likely have greater quantum efficiency than the dslr.

Ccd needs a laptop, dslr doesn't.

Ccd if cooled will likely have less noise than dslr.

Dslr will likely have a much larger chip than ccd.

Dslr will run out of power before ccd probably, unless external power supply.

Ccd may allow you to do planetary avi too, probably better than dslr.

You could use the dslr to do wide field images without a scope, which would be unlikely with the ccd.

Just some arguments for an against.

James

[ollypenrice]

I think it would be worth it but I wonder why you're dead set against mono for now. I help lots of beginners to get started and many of them feel, wrongly in my view, that OSC must be easier. It ain't necessarily so. They all get along fine with our mono setups in no time.

Olly

[jambouk]

It's probably a mental barrier olly. Like not wanting to go from an alt-az mount to an equatorial one.

For me, i can't face the thought of needing a filter wheel, filters, changing focus, relying on a laptop, having to process four sets of the same data and then overlay them all.... The appeal of one image which is less detailed but less hassle appeals to me

James

[davew]

Hello.

I've live in light polluted area ( Watford Hertfordshire). I'm using modified Canon 1000d. Just wondering to move for Osc camera ( Qhy8l with Idas filter. I know that the best solution will be mono and narrowband imaging but it's not really for me. Not now. Do you think these move is reasonable or is totally pointless?

Willbe grateful for yyour opinions.

Marek.

If it's just a mental thing ( Like Jambouk ) then can I suggest this strategy, unless you are insistent on colour.

Get a mono CCD and filter wheel. Buy just one filter, an Ha, and do some mono images. Even faster than OSC and much less hassle to learn to process. Once that's sorted then get an OIII. You'll have learned all about Mono processing so OIII is the same but normally fainter. Now step three is to combine then. Eventually get LRGB filters. A fairly painless route that spends money over a long period.

Running parallel with that is still getting colour with the DSLR and combining the narrow band wavelengths.

If you do fancy the OSC route and don't want to be swayed then ignore all pressure to change your mind  Many do. Some live to regret it and some don't ( Ignore that bit )

Dave.

[Gina]

I like mono cameras so much that I spent a lot of time (and money caused by failures) on removing the colour filter array (AKA Bayer matrix) from DSLRs to convert them from colour to mono and at the same time increasing sensitivity.  I then go on to set-point cool my cameras to at least -10C and often -15C.  The mono one (a 450D) will also have a built-in filter wheel within its outer casing.  Have to say I love extreme modding

[russellhq]

I made the move from DSLR to OSC, specifically an 1100D to QHY8L. I didn't really notice a great change in image quality or sensor sensitivity, but what I did like was the set point cooling the QHY8L was able to offer over the DSLR. This, for me, was the biggest advantage of the OSC over the DSLR.

I would love to give imaging with a mono sensor a go, but it is a lot more expensive. For example, I could get a QHY8L plus 2" Hutech filter for less than half the cost of an Atik 383L Plus, filter wheel and LRGB filters.

[redfox1971]

I'm makeing plans on updating my equipment,the only thing that puts me off mono over color is the lack of clear nights in the uk,I been looking at the qhy8l and the pro version,can the 8l be used with APT liveview for focusing or is that we're the pro version with progressive scan would only work with liveview?

[russellhq]

Yes, APT can be used to focus, I've used it. But I now use the supplied software and a Bahtinov mask to focus. I find this the simplest/quickest way to focus with my set-up.

[Gina]

Because mono lets you capture images in less time, mono is the best choice when time is limited.  Also, you can process mono images better as you have much more control.  OSC seems easier but until you've tried mono you won't know.

[sloz1664]

I have both a mono & an OSC ccd cameras. They both have their merits. Agreed the mono  

once set up is better as you gather more data per session and is less painful to post process

once you get your colours set correctly. downside is the time to take flats for your different filters.

I know you can use a common flat but that does not take out dust motes on the individual filters. 

The OSC is easier to set up, one set of flats and you're done. But, post processing like the dslr is harder to master.

Would I sell my OSC, no way.

As Olly pointed out in a previous thread:

1st Mono

2nd OSC

and a distant 3rd DSLR.

cheers

Steve

[ollypenrice]

Here's the speed equation, mono versus OSC. We assume a 4 hour shoot and we give a score of 1 unit of captured light (UCL ) per colour per hour.

We note that a colour filter blocks 2/3 of the light and that a luminance filter passes all of it.

First hour.        OSC 1UCL. Mono red filter 1UCL.

Secnod hour    OSC 1UCL. Mono and green filter 1UCL.

Third hour        OSC 1UCL. Mono and blue filter 1UCL.

Fourth hour      OSC 1UCL. Mono and L filter 3UCL.

OSC total, 4UCL. Mono 6UCL.

There's more; the mono can bin the colour, multiplying sensitivy by around 1.5 to 2x. Call it 1.5. This lifts the mono's score to 7.5 UCL.

So the mono wins by either 6 to 4 or 7.5 to 4 with a small loss in final quality when binning colour.  I can see no flaw in this logic but am open to the ideas of those who can.

The OSC advantage is the psychological frustration factor but shooting LRGB,LRGB reduces this drawback in mono shoots.

LRGB imaging was invented as a time saver.

Olly

[SnakeyJ]

The long running debate for mono vs OSC have been well made in numerous threads and, for me, mono certainly seems to have won the upper hand.    But I have no doubt the debate will continue.    The biggest drawback from my perspective is purely the cost of big mono CCDs + the FW and filters.    The KAF8300M based cameras have produced excellent results and DSLR like FoV, but these are now quite old sensors with relatively low QE compared to the newer chips, yet the cost of jumping up to 694/814 chips looks expensive considering the reduced FoV.     It would be nice to see a similarly sized more modern replacement for the KAF8300M, before parting with £ 2K for camera and FW.          

£ 2k for Mono/FW or £ 900 for OSC as a step up from DSLR?

[todd8137]

When i refer to ccd i mean OSC camera; dslr = dslr....

Ccd will likely have greater quantum efficiency than the dslr.

Ccd needs a laptop, dslr doesn't.

Ccd if cooled will likely have less noise than dslr.

Dslr will likely have a much larger chip than ccd.

Dslr will run out of power before ccd probably, unless external power supply.

Ccd may allow you to do planetary avi too, probably better than dslr.

You could use the dslr to do wide field images without a scope, which would be unlikely with the ccd.

Just some arguments for an against.

James

t my

Dslr's can run of laptops I prefer back yard eos to get my images,both cameras are good a osc would be better as the noise would be reduced converters can be used to run both cameras in the field

Pat

[russellhq]

Here's the speed equation, mono versus OSC. We assume a 4 hour shoot and we give a score of 1 unit of captured light (UCL ) per colour per hour.

We note that a colour filter blocks 2/3 of the light and that a luminance filter passes all of it.

First hour.        OSC 1UCL. Mono red filter 1UCL.

Secnod hour    OSC 1UCL. Mono and green filter 1UCL.

Third hour        OSC 1UCL. Mono and blue filter 1UCL.

Fourth hour      OSC 1UCL. Mono and L filter 3UCL.

OSC total, 4UCL. Mono 6UCL.

There's more; the mono can bin the colour, multiplying sensitivy by around 1.5 to 2x. Call it 1.5. This lifts the mono's score to 7.5 UCL.

So the mono wins by either 6 to 4 or 7.5 to 4 with a small loss in final quality when binning colour.  I can see no flaw in this logic but am open to the ideas of those who can.

The OSC advantage is the psychological frustration factor but shooting LRGB,LRGB reduces this drawback in mono shoots.

LRGB imaging was invented as a time saver.

Olly

I think we sohuld all agree Mono is quicker than OSC, but what I can't quite get my head around is that in that first hour, the OSC is capturing R, G & B. So does that mean you have an hour for each channel? So 3 in total...

[ollypenrice]

I think we sohuld all agree Mono is quicker than OSC, but what I can't quite get my head around is that in that first hour, the OSC is capturing R, G & B. So does that mean you have an hour for each channel? So 3 in total...

It isn't really catching R,G and B at the same time. It is catching R,G or B on a pixel by pixel basis. A quarter of its pixels are catching R, half are on G and a quarter are on B. The key point is that the colour filters are in place all the time. This is the equivalent of imaging in RGB only with a mono camera. If a mono imager only uses RGB (and not luminance) then he or she images at OSC speed.

We can also talk about Ha (and other NB filters for mono.) While we think of Ha as enhancing detail it is also a time saver on emission nebulae. In order to approach an HaRGB image of an emission nebula an OSC would need an utterly staggering amount of data. Even then, I don't know for sure that it would ever get there on the fainter targets.

Point taken about the cost of the QHY OSC camera. I haven't used one so I can't comment. I wouldn't write off the 8300 chip though. I wouldn't recommend it in OSC. The SBIG I've seen was really sluggish. However, the mono versions give a good result despite the unfavourable numbers. The numbers for my 11000 are also unfavourable but I just ignore them and get on with it. This Veil nebula had only 8 hours (HaOIIIRGB) per panel but I think it's gone fairly deep. QE of 50% sounds bad, though.

http://ollypenrice.smugmug.com/Other/Best-of-Les-Granges/i-tP4vF2J/0/X3/VEIL%20COMPLEX%20HaO111RGBWEB-X3.jpg

Olly