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Old 02-10-2009, 01:14 PM
Joel Warren
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Location: Amarillo, TX USA
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DBKAU21.AF first night out

Hi everyone,
Cloudy nights has been down awhile, so I thought I would post this here. As some know, I've had issues with Firewire and frame dropping/freeze ups. TIS sent me a USB version for evauation. I'll copy and paste and e-mail I sent to John at TIS. I have a few questions, like about the gamma you will see in the e-mail, and if anyone can answer that for me or give me any other input, I would appreicate it.

Hi John,
I took the DBK AU out tonight even though seeing was awful. I'm happy to report for now, no dropped frames at all, ran smooth. The codec we discussed seemed to be the one I was looking for. One thing I don't understand is that with the DBK AF, planetary imagers like myself always kept the gamma at 10, or zero, the lowest setting. This is impossible with the DBK AU. You will have a black screen if you you keep the gamma at zero. So, now I'm trying to find out what the optimum setting for the gamma is with the USB version. Also, there is one thing I was very disappointed with. I don't know if you sent me a used camera or what, but the CCD chip was filthy. It was as if someone dumped a load of dirt on it. It was totally and completely unusable due to the amount of debris on the chip. If this was a new camera, you guys have a quality control issue over in Germany. I have a feeling this camera must have been used by others for evaulation, because I have no idea how it could have gotten so dirty. In all my years of imaging, I've never seen a chip or filter that bad before and I had to spend a good hour cleaning it. If I do end up buying this camera, we will have to discuss that, because either like I said, this is a used camera, or there is a real quality control problem during manufacturing. I have a good relationship with you guys and your cameras have given me hundreds of great images and I always promote your product, so I want you to realize I'm telling you the truth in regards to the condition of the ccd chip. Someone really dropped the ball on that. Hopefully in a few weeks I'll have enough nights to decide if USB will be the way to go for me, but someone needs to look into how that could happen to the ccd chip.

Best wishes,
Joel

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  #2  
Old 02-10-2009, 01:22 PM
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citivolus (Ric)
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I'd guess that the one you got has been used for prior evals. I've owned three of their cameras and all of them arrived with spotless sensors.

All of mine have been DMK (mono) though, so I can't answer your gamma question, other than to say that you want to maximise your data by having the brightest regions closer to saturation to minimise quantisation error. If gamma is set very low and the image is dark, you are really limiting the useful dynamic range, given the 8 bit ADC in these cameras.

Regards,
Eric
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Old 02-10-2009, 04:49 PM
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matt
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My DMK (mono) arrived with a fair amount of debris on the chip too. It seemed to come from the surrounding packaging.

As for your gamma question? Sorry, I've only ever used the DMK model.
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Old 02-10-2009, 09:15 PM
Joel Warren
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Location: Amarillo, TX USA
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I do believe the DBK AU will be going back. Just tried it out on Mars, and the color of Mars on that camera was a blood red/maroon/purple, where as it should be a pale yellow with a white NPH. My DBK AF camera captured some very find Mars data this morning, but no matter what I tried, and I tried everything, there was no getting rid of that screwed up red color of Mars on the USB camera. I tried it all, white balance auto/off, saturation, hue, everything, but something is really a miss. Any ideas appreciated. I am glad to say the DBK AF performed flawlessly this morning, and I got some great data.
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Old 03-10-2009, 01:18 AM
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Merlin66 (Ken)
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Did you get a reply from TIS??
I have a DMK21 AF as do many of the other forum members in the UK.
I've never heard of anyone experiencing any dirty CCD chips from TIS.
They have always given fantastic service and support.
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Old 03-10-2009, 06:05 AM
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troypiggo (Troy)
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My DBK arrived spotless, but the only time I have used it for imaging I got a purple Jupiter. See here for a 10s clip. I would like to get to the bottom of this also. I figured it must be a codec or setting or something.
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