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My first Saturn... with a DBK camera


Jupiterholic
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Finally got my new DBK working last night and got my first shot with it through my new 3x Televue Barlow. The SPC900 has now gone to webcam heaven as it was frustrating the hell out of me. Seeing was pretty ordinary so its a little bit softer than I'd like but the use of an IR block filter brought out some storm detail.

Still got a lot to learn about this camera, mainly cause it doesn't come with instructions :D so I'm pretty sure I can get better shots than this.

Never ceases to amaze me when I look up at it in the sky and think how we can turn that tiny yellow dot into this.

post-22195-133877608805_thumb.jpg

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imho a DBK cam is capable of fine imaging when the seeing is good through reasonable apertures.....I have very fond memories and high regards for my former planetary imaging camera..!;)

A very promising image for your first take with it..!:D:p

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Thanks all,

Yeah once I actually learn how to use it I'm hopeful of getting some good results from it. Bit annoying that they don't issue manuals with these things and just assume you wouldn't buy it unless you're an 'expert' which I'm most definitely nowhere near being.

Don't think I have enough aperture to really push its framerate and use it to its fullest on dim Saturn though, Jupiter and the moon however....

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Yep good start with the DBK, only 8" here too. impressive given saturns current situation. looks like your using the colour histogram. if your not. you got lucky. the rings look pretty neutral. You wait till jupiter is back your DBK is going to amaze. its better on jupiter trust me

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Yep good start with the DBK, only 8" here too. impressive given saturns current situation. looks like your using the colour histogram. if your not. you got lucky. the rings look pretty neutral. You wait till jupiter is back your DBK is going to amaze. its better on jupiter trust me

I am proper looking forward to tackling Jupiter. I've got countless SPC900 shots of it from last year so it'll be really interesting to compare the two cameras.

I think I must have gotten lucky with this one as it was a really muddy brown when I put debayering on in registax, but photoshop sorted most of that out so the colour shades must have all been in there somewhere. I haven't experimented with the colour histogram yet so I'll put that on the long list of things to learn how to do with this camera!

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Good pic Jupiterholic. I hope you enjoy the camera. Roll on Jupiter!

I also just bought a DBK to replace my NexImage. I'll post my pics later in the week when I have some time. But, I wanted to ask you which colour space you set on the DBK. I ask, because my first images had a sort of ghost on the east side. At first, I thought it a ringing effect from going too heavy on the wavelets. But, over several nights, it was always there and always on the same side.

On the last two nights, it disappeared. I think it was because I changed the colour space from YUY2 to Y800, which is lossless. Perhaps the compression was causing Registax difficulty during the alignment process. But, I changed a few other things, so I'm not certain. With such little imaging time now, it's difficult to take a scientific approach :)

I can see a similar effect on your picture on the left side, which I suppose is becoming the darker side of Saturn as we move away from it. Are you using Y800 or YUY2?

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Yeah you're right, there's a little bit of that ghosting going on in the shadow area isn't there.

I used Y800 for this. I'm sure you know all this but as I'm still way green when it comes to these cameras, I read somewhere that you have to use that if you want to push the framerate past 30fps and do the colour in registax afterwards with debayering. Hence the onscreen image was grey.

In hindsight, it doesn't seem to matter with Saturn as with my 8 inch SCT I can't go anywhere near 30fps anyway, which according to this source I found is the limit if you want to display colour live on screen. Might try the other colour spaces if I get any more Saturn opportunities. Its still about a month away from going behind my house and still quite high so we'll see. Seems to just be rubbish seeing everytime I try though. Stupid english weather.

Not sure what to suggest for the ghosting problem, but if you achieve any significant results let me know.

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Nice pic. But I am a little surprised you could get a better result out of the DBK than the SPC900. I would have thought that Saturn was too dim to crank up the frame rate past what the SPC900 can achieve and therefore the DBK would give no advantage.

Now when Jupiter rolls around, that will be a different story!

Cheers,

Chris

Edited by cgarry
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Jupiterholic: Don't get me wrong. It's a fine picture. You picked up the storm and the Cassini Division nicely and the colours are particularly good. I am on the same learning curve as you and it's a steep one. The DBK takes some getting used to after my NexImage.

I'm also using a TV x3 Barlow, but my scope is F/7.5. I guess yours is f/10, so you're pushing things a little harder than me.

I agree with Chris that one cannot expect more from the DBK than the SPC/Neximage family; at least, not on Saturn. After all, they use the same sensor. I set the exposure between 1/8s and 1/11s. If I try and push it to 1/15s, things go wrong. As you say, things will be different with Jupiter, and this is just a practice run for Jupiter.

Not wishing to hijack your thread with my own woes, I'll start a new thread later this week with my experiences. Looks like we're learning together :)

Cheers,

Tom.

Edited by 26Left
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hijack away if you like, or I'll join your new one to compare notes!

@cgarry. Yes I completely agree re: spc vs DBK on Saturn. The main reason I bought it was for Jupiter and the Moon, but I was also finding on Saturn using my 3x barlow with the SPC that I needed to push to at least 15-20fps to be able to get enough frames at that mag before it drifted off the screen. This was leading to some pretty horrendous compression (I've attached my best 3x barlow effort with the SPC here)

The advantage of the DBK has been that I can get all those frames without the compression. So really its opened up my 3x barlow for use.

post-22195-133877611102_thumb.jpg

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Okay, now I understand why you were struggling with the SPC. Your signal levels must have been very low at F/30 with frame rates that high, I am impressed with the results.

I actually have a DBK 21AF04.AS myself, that is the FireWire version of your cam. I found that I could not get a better image of Saturn with the DBK than the SPC so I put the DBK away in its box to wait for Jupiter to arrive. I really enjoyed getting all that I could out of the SPC, especially as it gave me a chance to compare my efforts with the many other SPC imagers on the forum.

However, when Jupiter is suitably placed I shall break out the DBK and join you guys on the DBK learning curve.

Cheers,

Chris

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Well, here my most recent effort with my DBK. I've taken better, but I'm quite pleased with this, and I think I'm beginning to understand the camera.

I was a six minute run, taken with my Meade 127 refractor and a x3 TV barlow and tubes, giving me F/30. Stacked with R6 (kept about 70% of frames) and a little work in PS.

What I've discovered is that the gain can be set to full (1023) and the avi will still stack well. That surprised me, because I always tended to keep gain low on my NexImage. Far more critical is the gamma control. Between 60 and 80 works best for me. Any higher, and I end up with little dynamic range and an run that does not stack well.

So, for Saturn, I set the gain to full and gamma to about 70. Then, I alter the exposure to aim for a histrogram peaking at 80% or so. With this image, my exposure time was 1/9s. My strategy will probably be completely different for other targets.

Can anyone else with a DBK confirm that this is a reasonable strategy? It's completely different to what I was used to with my NexImage, where I never moved gamma off zero.

I use the Y800 colour space and press the debayer button, which I think debayers the video either in the camera itself or the IS Capture software - not sure which. I'm also experimenting with lossless codecs like HuffYuv to try and keep the file sizes down without compressing video. I'm not sure whether I should debayer while capturing or use other software like VirtualDub to debayer later. I assume that the IS debayer algorithms are reasonable, but perhaps I should experiment.

I think the surface brightness of Jupiter is two or three times that of Saturn, so, when the time comes, I'm hoping to be able to capture at 30FPS with Jupiter.

I still have lots to learn!

post-26426-133877611306_thumb.jpg

Edited by 26Left
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Well, here my most recent effort with my DBK. I've taken better, but I'm quite pleased with this, and I think I'm beginning to understand the camera.

I was a six minute run, taken with my Meade 127 refractor and a x3 TV barlow and tubes, giving me F/30. Stacked with R6 (kept about 70% of frames) and a little work in PS.

What I've discovered is that the gain can be set to full (1023) and the avi will still stack well. That surprised me, because I always tended to keep gain low on my NexImage. Far more critical is the gamma control. Between 60 and 80 works best for me. Any higher, and I end up with little dynamic range and an run that does not stack well.

So, for Saturn, I set the gain to full and gamma to about 70. Then, I alter the exposure to aim for a histrogram peaking at 80% or so. With this image, my exposure time was 1/9s. My strategy will probably be completely different for other targets.

Can anyone else with a DBK confirm that this is a reasonable strategy? It's completely different to what I was used to with my NexImage, where I never moved gamma off zero.

I use the Y800 colour space and press the debayer button, which I think debayers the video either in the camera itself or the IS Capture software - not sure which. I'm also experimenting with lossless codecs like HuffYuv to try and keep the file sizes down without compressing video. I'm not sure whether I should debayer while capturing or use other software like VirtualDub to debayer later. I assume that the IS debayer algorithms are reasonable, but perhaps I should experiment.

I think the surface brightness of Jupiter is two or three times that of Saturn, so, when the time comes, I'm hoping to be able to capture at 30FPS with Jupiter.

I still have lots to learn!

Thats a nice shot. The seeing is rubbish at the moment aswell, you did a hell of a lot better than my recent attempts.

I found 108 was my gamma sweet spot for Saturn and 1/15s at 15fps. Though god knows if thats the best combination. As it happens I seem to have miscalculated my remaining Saturn opportunities and tried last night and noticed it was about to go behind my chimney. So I have the heat haze from the house to contend with aswell now. Consequently I'm giving up on Saturn. I'm pretty pleased with the 9 images I got of it this year and I think cgarry had some valid points about the SPC. I may keep my SPC900 exclusively for use with Saturn as it did seem to produce some really good results with my 2x barlow.

Edited by Jupiterholic
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Actually, our images aren't that different. Your is exactly half the image scale of mine. I only have a 5" scope, so I can't push things that hard, and, as you say, seeing is rubbish at the moment anyway.

I just downloaded your picture into Photoshop and made the same adjustments as I did to my own, which is to adjust the curves a little. Then I scaled your down 50% to match mine. They are almost identical, except that your colours are more natural and the Cassini Div on yours curves round a little, whereas mine is more like a couple of black dots.

Not that surprising I suppose. Same planet; same camera; same conditions. Well, just a bit of fun :) I'll try and send you the image in a PM.

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