Difference between DMK21 and DMK41?

[BigDunc78]

What is the difference between the two cameras?

[Psychobilly]

Amongst other things...

Sensor Size, Sensor resolution Max Frame rate... oh and last but not least .... Price...

Here's a link to the Manufacturers website with the comparison spec table...

The Imaging Source USB Astronomy Cameras

Peter...

[ollypenrice]

For a quick rule of thumb, 21 for the planets and 41 for the big stuff - sun and moon. If you can't decide, isn't there a 31 as well - the Tony Blair of DMKs!!

Olly

[Merlin66]

Good one Olly!

[riklaunim]

Well, DMK21AU618 would be better than DMK31 even for the Moon. Less pixels but more sensitive and fast with no artifacts. The big problem of DMK31 and 41 is no ROI with faster framerate.

[PeterW]

So DMK41 for the diehard Solar/Lunies and the DMK21 618 for everything else... unless you love stitching frames together. The 618 is more sensitive so shorter exposures... hopefully more crisp frames.... darn I need to save up again!

PEterW

[riklaunim]

Point Grey Chameleon or other ICX445 camera - for the lunar/solar too. AFAIK it can be cheaper than DMK41. And they usually have ROI with framerate option.

[Flyingpig]

Can someone explain - whats ROI stand for?

I bought one of these about three years ago when I was fairly new to astronomy and when advice on them was very thin on the ground. Unfortunately I bought the DBK41 which is the colour version since I wanted colour images - not knowing about the mono LRGB method.

I have only used it a couple of times in bad seeing and on targets like the moon and the Pleiades.

[Macavity]

Does anyone have any idea of the "lux" sensitivity of these cameras? I reviewed them as an option, before becoming cheerfully embroiled in this (Watec) Video Imaging malarky...

[Merlin66]

ROI > "Region of Interest" Generally the ability to select a sub-frame to speed up image aquisition.

[Flyingpig]

ROI > "Region of Interest" Generally the ability to select a sub-frame to speed up image aquisition.

Thanks Merlin. (sorry dont know your real name)

Phil

[riklaunim]

Does anyone have any idea of the "lux" sensitivity of these cameras? I reviewed them as an option, before becoming cheerfully embroiled in this (Watec) Video Imaging malarky...

Lux values are hardly comparable as they are measured with some lens in some way. Absolute quantum effieciency is the key factor marking sensitivity, for example on this chart:

http://airylab.net/Images-site/Basler/QE.png

DMK21 - ICX098

DMK31 - ICX204

DMK41 - ICX205

DMK21AU618 - ICX618

[Macavity]

Lux values are hardly comparable as they are measured with some lens in some way. Absolute quantum effieciency is the key factor marking sensitivity...

Thanks indeed. Sorry to drift slightly off-topic, but I really wanted to understand (get some pointers to) that.