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Old 13-01-2013, 02:14 PM
LAW (Murphy)
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Quote:
Originally Posted by RickS View Post
The colour filters are built into the sensor in a DSLR or OSC camera so there's no way to avoid their use. When you produce a black and white image from a DSLR it is, as you suggested, just mapping the colours to grayscale values.
Thanks Rick, I thought that must be the case.
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  #22  
Old 13-01-2013, 09:52 PM
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Quote:
Originally Posted by BlackWidow View Post
I work for myself so find it difficult to do all nighties to get Lrgb images, so a color CCD was the best option for me.



Mardy
This is a misconception that many people can't seem to get their heads around. If you take a OSC picture, then you can get an equivalent (same SNR) LRGB pic in a shorter time. If you are time pushed for taking exposures, then you need a mono rather than a OSC. As I said in my earlier post, just do the maths on numbers of photons gathered.
Geoff
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Old 14-01-2013, 05:51 PM
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Quote:
Originally Posted by ghsmith45 View Post
This is a misconception that many people can't seem to get their heads around. If you take a OSC picture, then you can get an equivalent (same SNR) LRGB pic in a shorter time. If you are time pushed for taking exposures, then you need a mono rather than a OSC. As I said in my earlier post, just do the maths on numbers of photons gathered.
Geoff
That's true. At the end of the day its the sensitivity of the sensor to light that matters (QE - what percentage of light hitting the sensor is converted to a signal?).

Early model DSLRs QE is on the low side of around 25-35%. Some later models have quite high QE. The Sony Exmor sensors are currently the highest
ie. in Sony cameras like Sony A99, RX1, Nikon D800, Nikon D600.

Greg.
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Old 14-01-2013, 06:08 PM
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BlackWidow (Mardy)
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True but

Quote:
Originally Posted by ghsmith45 View Post
This is a misconception that many people can't seem to get their heads around. If you take a OSC picture, then you can get an equivalent (same SNR) LRGB pic in a shorter time. If you are time pushed for taking exposures, then you need a mono rather than a OSC. As I said in my earlier post, just do the maths on numbers of photons gathered.
Geoff
Yes this I understand. However unless you pay larger amounts of money on filter wheels etc it does not shorten the workload required. I have a port setup so it all adds up to workload not exposure times. That said more money makes for better equipment that makes the job easy and faster. This is not always the case for all people like me ( sadly). My choice is still as it was.. OSCAR for low cost performance. I still see your point of view and thanks for the information as some of it I was not aware of.


Mardy
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