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mick pinner
19-08-2008, 10:44 PM
what are the basic differences between the DMK21 and 31 colour cameras?
l am aware that combined filtered images with a mono camera are better than the straight colour camera but percentage wise just how much better. thanks.

iceman
20-08-2008, 05:23 AM
Hi Mick

The advantages of the mono can be broken down into:

1. Greater resolution (60% better). The mono allows the full 640x480 resolution in each colour channel. The colour bayer matrix only captures 33% resolution in each channel.
2. Ability to change settings each colour channel: Ensures proper weighting of the histogram in each channel
3. Ability to refocus each colour channel: Ensures a sharper image in each channel.

Is your question comparing the DMK21 to the DBK31, or in general, the DMK (mono) to the DBK/DFK (colour) versions?

What's your intention with the camera? Lunar or planetary imaging?

RB
20-08-2008, 08:59 AM
One basic difference is that the DMK21 is 640x480 pixels and the 31 is 1024 x 768 pixels. :D

mick pinner
20-08-2008, 12:52 PM
thanks Mike and Andrew, colour to colour and mono to mono Mike.
planetary work mainly, because l won't be doing a great deal of imaging l was wondering if it was necessay to get heavily into the filtered mono images or if the colour version will give reasonable results.

Dennis
20-08-2008, 01:10 PM
Hi Mick

I find that there is a noticeable difference in “image brightness” on the screen between my DMK21 mono and DBK21 colour.

I like to use the DBK21 colour for colourful double stars, but some of the doubles and their components are so dim that I often have to change the DBK for the DMK just to get an image on screen.

Also, I have noticed a marked difference in “image quality” between the DMK21 and DBK 21 when viewing Jupiter in mono and colour respectively. The DBK colour image looks very grainy due to the high gain required to set an exposure of say, 1/15 to 1/20 sec at 30fps whereas the DMK21 mono looks much smoother as the Gain need not be as high to achieve the optimum shutter speed and frame rate.

If I wanted to specialise in high resolution planetary imaging, I would go DMK plus colour filter wheel and colour filters. However, as more of a space tourist, I am happy to accept the limitations of the DBK to produce images that meet my requirements and satisfy my personal goals and standards which attract me to this wonderful hobby of ours.

Cheers

Dennis

mick pinner
20-08-2008, 01:38 PM
thank you Dennis, l really want to do some planetary imaging as a side line only, but l'm not sure l have the time to devote to the processing required with mono/filtered images. maybe l should.