DMK21AF04 arrived!

[asimov (John)]

Some valid points Dave But then we have the other side of the coin: To DO get the DMK for its potential to capture at 60 FPS uncompressed precisely because one does live in an area where good seeing is few & far between!

To my way of looking at that, you get to stack more crap 3/10 frames, big deal! I can't see any advantage it that really.

[iceman (Mike)]

I think Dave's points were more about mono vs colour..

The uncompressed high frame rates are still a reason why the colour DMK would be better than the colour ToUcam. If the seeing is only 3/10, with uncompressed high frame rates, you've got a much better chance of capturing frames in moments of good seeing - even if the air is generally unsteady that night.

If you're capturing 3 times more frames in the same period of time, chances are you'll get more chance of capturnig enough sharp frames to stack.

The other advantage is noise - from Chris Go's reports, the DMK's have far less noise than the ToUcam, and he regularly captures at 80% gain and ABOVE. Try doing that with the ToUcam and see how grainy it turns out.

[davidpretorius]

Originally Posted by gbeal

Arggghhhhh Davo,
how am I going to sell this now???.

Not to worry, I will be needing one in the next 6 months ie mono and then work on a motorized filter wheel!

[Robert_T]

Originally Posted by davidpretorius

my impression re colour vs mono cameras:

If I lived in canberra, SA, melbourne, hobart and wanted to image, then i honestly believe that the mono camera would not be used to it full capacity due to conditions outside your control.

don't forget Brisbane in Winter You're making sense DP, but it's expensive sense that might lead me to investing in a Meade 14in rather than a Lumenera....

[asimov (John)]

Originally Posted by iceman

The uncompressed high frame rates are still a reason why the colour DMK would be better than the colour ToUcam

I'm in total agreement there, plus within range budget-wise for someone like me...the only problem being....the laptop. If I had to get a bigger/better/faster laptop than the one I just bought I'm out of the race again.

Can't wait to see what you get with your mono DMK & looking forward to Lester getting his colour version up & running before this apparition of Jupiter is over.

[iceman (Mike)]

In other news, Chris Go and Oldfield (on CN) both said that they had problems capturing at 30fps as well, and they got a new version of the software (drivers + IC Capture) sent to them which fixed the problem for them.

I've sent TIS an email and hopefully that will fix it for me too.

[Robert_T]

Originally Posted by iceman

The other advantage is noise - from Chris Go's reports, the DMK's have far less noise than the ToUcam, and he regularly captures at 80% gain and ABOVE. Try doing that with the ToUcam and see how grainy it turns out.

Mike - The Phillips 900nc might have a similar advantage, I routinely capture at 80% gain with it (necessary is you're going 1/33rd sec) and occasionally higher to 90-100% (for 1/33rd sec with 4x powermate) without too much grain

[asimov (John)]

Originally Posted by Robert_T

Mike - The Phillips 900nc might have a similar advantage, I routinely capture at 80% gain with it (necessary is you're going 1/33rd sec) and occasionally higher to 90-100% (for 1/33rd sec with 4x powermate) without too much grain

Yep. 85% is about right in some cases for me.

[iceman (Mike)]

Well the DMK has had first light! I used an 1.25" adapter to screw into the DMK, which slotted into the 5x powermate.

Still only using 15fps at this stage - new version of IC Capture helped a bit, but I need some more experimenting cause i'm still locking up occassionally at 30fps.

Captured about 6 or so avi's. The fast frame rate makes every wobble more noticeable. Even just bumping the DMK cable makes the image wobble. Although my scope and platform is quite unsteady at the moment and needs more dampening time than i'd like.

Tried hooking up the ATik manual filter wheel, but I think i'm missing an adapter or two that I need. So that extra weight and wobble will have to wait for another time. Need to speak to Steven Mogg and find out what I need.

Anyway, will process the avi's overnight and tomorrow morning and post the results. I took some ToUcam images at the same time, so some comparison will be able to be done. Should be interesting!

[iceman (Mike)]

Oh one thing I noticed is the smaller image scale of the DMK, when compared to the ToUcam. Due to it's larger chip or larger pixel size or something I guess.

By the time the filter wheel is added on, it will add some extra focal length so it will probably come out about the same.

[davidpretorius]

this is very exciting ice, can't wait.

I noticed Birds are also smaller than a normal toucam. Techically I spose you can image bigger with more focal length for the same pixel size.

Steve made me up some t-thread to 1.25" and t-thread to 2" adapters, give me a hoy if you need to look to see if they fit and i can airbag to you

[Dennis]

Originally Posted by iceman

Oh one thing I noticed is the smaller image scale of the DMK, when compared to the ToUcam. Due to it's larger chip or larger pixel size or something I guess.

By the time the filter wheel is added on, it will add some extra focal length so it will probably come out about the same.

Hi Mike

I just checked the DMK specs at http://www.1394imaging.com/en/produc...specification/ and the pixel size is H: 5.6 µm, V: 5.6 µm and the resolution H: 640, V: 480 making it the same as the ToUcam? Weird? Must be some other factor at play here?

Cheers

Dennis

[asimov (John)]

Originally Posted by iceman

The fast frame rate makes every wobble more noticeable. Even just bumping the DMK cable makes the image wobble. Although my scope and platform is quite unsteady at the moment and needs more dampening time than i'd like.

Interesting. I used to get my jollies by previewing jupiter in extremely bad seeing (the big undulations) @ 25 FPS. Boy, talk about high speed oscilations! Funny to watch.. I'll shut up now

Looking forward to seeing what you got!!

[iceman (Mike)]

Oh one other thing, my DMK already has dust donuts Need to clean them tonight before another imaging session.

Will post first light sometime this morning, chugging through registax now. I've passed the ToUcam versions through a quick registax run and the seeing looked ok, maybe 5.5/10.

[Robert_T]

On the image scale thing, as Dennis notes the pixel size is the same (in fact it should be the same chip as used in Toucam's and mono versions of this like the ATIK etc. Only thing I can think off is differences in the camera body and adapator that end up placing the chip of the Toucam further away than in the DMK?

The Lumenera I'm considering has 7.4 micron pixels which will make image scale 30% smaller. I wonder does this mean that to get the same image scale the seeing will be even more critical?

[Lester]

Hi Robert,

If the chip was further away the focus would have to be altered accordingly, (I would think).

[davidpretorius]

where is bird when we need him?

i am sure he said it is smaller with his dragonfly.

Also what makes the toucam act as a 6mm eyepiece??? distance to chip??? the size of the opening???? i have never found out!

[Robert_T]

Originally Posted by Lester

Hi Robert,

If the chip was further away the focus would have to be altered accordingly, (I would think).

Lester - yes it would I expect. What I'm getting at is that the distance of the chip from the powermate will determine the amplification of the powermate. It acts as a pseudo extension.

cheers,

[Lester]

The chip must always be at focus point. Cannot move it further away to make larger image if not at that point.

[Lester]

Okay! With ya now.