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Astrophotography and Sketching >> Beginning and Intermediate Imaging

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JMac85X
super member


Reged: 09/13/12

Loc: California
DBK 21 Imaging new
      #5589182 - 12/26/12 02:39 AM

I just got a DBK 21AU Imaging Source camera for Christmas. I'm having issues with focus. I can focus the moon and it's craters pretty well, good definition. Jupiter on the other hand is my issue, I can't get it to focus right. It's just a white shiny ball at best. I don't know if it's because it's so close to the moon or what but it's frustrating. I use a televue 2x powermate and an 11 inch SCT.

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GreatGigInTheSky
sage


Reged: 02/06/11

Loc: Santa Clara, California
Re: DBK 21 Imaging new [Re: JMac85X]
      #5589201 - 12/26/12 03:55 AM

Hi. My first guess would be that you may have the gain too high, or the frame rate too low. I'm also using a C11 with a DBK, and find that with the frame rate at 60fps, the gain can be quite high (even max in ICC), but with lower frame rates, you may need a much lower setting. I would suggest that with this aperture and the DBK, good settings for Jupiter are 60fps and around 800 - 850 gain.

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JMac85X
super member


Reged: 09/13/12

Loc: California
Re: DBK 21 Imaging new [Re: GreatGigInTheSky]
      #5589205 - 12/26/12 04:11 AM

I'm very new at imaging, as in today. Mine won't let me go any higher than 30 fps and I don't know what you mean by gain.

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GreatGigInTheSky
sage


Reged: 02/06/11

Loc: Santa Clara, California
Re: DBK 21 Imaging new [Re: JMac85X]
      #5589209 - 12/26/12 04:19 AM

What software are you using for capture, the ICC software that comes with the camera, or something else? Whatever software you're using (and in ICC, it's labelled "gain") there will be a way to set the brightness of the captured image. If it's set for something too bright, then you'll get the effect you have described -- no matter how you try to focus, you'll only see a bright ball.

The hardware you have is certainly capable of 60fps. Again, curious about the software.

It occurs to me that the settings I gave you are for a 3x barlow, not a 2x. I expect the gain value should be substantially lower than 800.


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JMac85X
super member


Reged: 09/13/12

Loc: California
Re: DBK 21 Imaging new [Re: GreatGigInTheSky]
      #5589355 - 12/26/12 09:24 AM

.Okay, I found Gain under view - toolbars - exposure bar and from there it sets up on the top and the gain was marked auto which was at 1023. Hopefully I can try it out tomorrow night, it's been cloudy and raining off and on.

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darbyvet
scholastic sledgehammer


Reged: 10/19/10

Loc: Seneca Falls, New York
Re: DBK 21 Imaging new [Re: JMac85X]
      #5589366 - 12/26/12 09:39 AM

Jupiter can be very hard to focus if your seeing is poor. You should turn on the histogram setting on your toolbar.This will show you the histogram and you can use this to set your gain.you want to lower the gain until the histogram goes about 2/3 of the way across the x-axis.Focus also requires very small adjustments of your focuser.If you move too much you will move through focus.
You probably should be able to set the gain between 700-900 and you will start to see a sharper edge to the planet.Then move your focuser a VERY small amount and recheck the image and repeat until you have decent focus.


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jgraham
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Reged: 12/02/04

Loc: Miami Valley Astronomical Soci...
Re: DBK 21 Imaging new [Re: darbyvet]
      #5589575 - 12/26/12 11:49 AM

Yep, with the DBK21 set the frame rate to 30 fps, then adjust the gain so that the bright edge of the histogram is about 80% of full scale. To set the focus use a Bahtinov mask (or other focusing mask) on a bright star and then slew to Jupiter.

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JMac85X
super member


Reged: 09/13/12

Loc: California
Re: DBK 21 Imaging new [Re: jgraham]
      #5589817 - 12/26/12 02:10 PM

I was messing around with it last night around 5 in the morning. The histogram shows RGB, all seperated in there own graph right? Just staying on the planet without an autoguider is hard because it's moving, I would adjust the motor speed to one of the lowest settings and hold it down to stay with the planet and record. 30 seconds is all you really need right?

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RedLionNJ
scholastic sledgehammer


Reged: 12/29/09

Loc: Red Lion, NJ, USA
Re: DBK 21 Imaging new [Re: JMac85X]
      #5589829 - 12/26/12 02:19 PM

In order to maximize the S/N ratio (via stacking), you need the histogram to be as high as possible without clipping (the 80% John recommends is the lowest I would go) and the longer the total integration time (number of frames), the better. With OSC like the DBK you should be able to go for a couple minutes of data-collection before rotation becomes a major hurdle.

If you're only going to stack the best frames of a 30-second series at 30fps, you're likely to have a very noisy image.

Grant


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GreatGigInTheSky
sage


Reged: 02/06/11

Loc: Santa Clara, California
Re: DBK 21 Imaging new [Re: RedLionNJ]
      #5590151 - 12/26/12 07:12 PM

If you're somewhat polar aligned, then all that should be necessary is a little bump, say once a minute or so, to keep the planet in the field of view. I almost never do a thorough job of polar aligning when imaging planets, even at f/30, but at least a rough polar alignment is required. I've found 2 to 3 minutes to be a good recording time for Jupiter, maximizing the number of frames captured within the limit imposed by planetary rotation. As for histogram, I'm typically around 60%. Whether this leads to images that are too noisy, I would suggest you experiment and see for yourself. You might also take a look at my most recent Jupiter images, all recorded at about 60% histogram fill, and use your own judgement. There are a number of trade-offs here, with frame rate, gain, histogram fill, image scale, etc. and I think the only way to figure it out is to try things and see what works. Spend some time to learn what your setup will do at different settings -- try a range of values -- and take notes as you do it -- that will be your best guide.

As for Bahtinov masks, sure, if you have one, I'd encourage you to try it, but if you don't, you shouldn't feel that you have to get one to obtain good focus. I've never used one, nor felt the need. Focusing does take a bit of practice, but it's not that difficult -- just try it and get some experience.


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JMac85X
super member


Reged: 09/13/12

Loc: California
Re: DBK 21 Imaging new [Re: GreatGigInTheSky]
      #5590694 - 12/27/12 02:50 AM

I'm making progress, slowly. Tonight I was able to focus in enough to see the bands of Jupiter but no color. I set the gain all the way down to 250 and adjusted something else. It's so frustrating though. I'm not able to use the powermate because I can't keep it centered for more than a second, literally. Do you guys use autoguiders? It doesn't seem practical without one, it's really hard to tweak the image in the IC software that comes with the DBK camera.

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Adam E
Pooh-Bah
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Reged: 06/29/09

Loc: Edgewood, NM
Re: DBK 21 Imaging new [Re: JMac85X]
      #5590856 - 12/27/12 09:02 AM

You don't need an autoguider. You need to be polar aligned accurately. I find my Atlas' polar scope to be sufficient for 3 minute runs on Jupiter, but with my other mount that doesn't have a polar scope, I perform a quick and dirty drift alignment.

Learning how to polar align a mount with good accuracy, and getting enough experience to perform the alignment in a reasonable amount of time is pretty much a top fundamental skill needed for any AP, either DSO or planetary.

As far as IC Capture, here are my settings from a run on Jupiter the other night using my DBK21 and Meade 12 SCT on an Atlas.



Larger Link

...and the goods...



Larger Link

Note, that I do not debayer the data during capture, and I use the Y800 codec for the .avi capture.

This means I capture raw, B&W, data, and I send smaller data up the USB cable to my PC. I use a standard HP laptop, with USB 2.0, and I capture just fine at 60 fps.

After capture, I use AutoStakkert! 2 for debayering, quality assessment, alignment, and stacking. There's a ton of info on AS!2 over in the solar system imaging forum. Just do some surfing over there, or perform a search.


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GreatGigInTheSky
sage


Reged: 02/06/11

Loc: Santa Clara, California
Re: DBK 21 Imaging new [Re: Adam E]
      #5591265 - 12/27/12 02:18 PM

This is a hobby that rewards patience. Slow progress is normal. Adam's advice is all excellent. I would have shown you some screenshots myself if I were not away from home and my imaging PC this week. You might use his settings as a model to start with. One caution: Make sure debayering is off. It's the button right below the "W" in Window in Adam's screenshot, above. You won't see any color in the live feed this way. If you do see color, then debayering is on, and you'll get avis that are unusable. I've been bitten by this more than once. If you use AS!2 for stacking as Adam suggests (and I would suggest also) then the debayering happens there.

There is a piece of software that will do some limited guiding while capturing -- it's called FireCapture, but you'll need to be reasonably well polar aligned for this to work anyway. I would encourage you to work out the basics before trying FireCapture (if you are so inclined) in any case, as that's a whole different set of problems to work out before that's going to work well for you.


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JMac85X
super member


Reged: 09/13/12

Loc: California
Re: DBK 21 Imaging new [Re: GreatGigInTheSky]
      #5591297 - 12/27/12 02:53 PM

To be honest with the moon being full and clouds coming and going the only thing in the sky is Jupiter and the moon and maybe a handful of stars so I've been sloppy with the polar aligning. That's a different issue with me, polar aligning is kind of tricky for me. When I'm patient I get accurate but I need more practice. I've just been so excited to get a camera for my setup for so long now, once I saw it I couldn't stop thinking about using it and of course no stars, big bright moon. So I've been trying to wing it and got caught up in frustration. I've now have a handful of issues now that I have the camera. My computer runs at 95% when using the IC software when I click align or whenever it goes through all the images, the more the better chance it has to freeze the program, but don't worry my Jedi hero's, I'll get there.

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GreatGigInTheSky
sage


Reged: 02/06/11

Loc: Santa Clara, California
Re: DBK 21 Imaging new [Re: JMac85X]
      #5591435 - 12/27/12 04:25 PM

I definitely understand the excitement -- it's great being able to image this stuff, isn't it? To aid polar alignment, I always set up in the same place -- the tripod legs always go on the same 3 bricks, then I know the polar scope is pointed very close to Polaris, and all I need to do is adjust a small amount to get it aligned well enough for imaging.

You definitely need a PC with some processing power -- I've got an older Intel Core 2 Duo laptop, which I find is just adequate to keep up when capturing. My processing happens on a quad core. While not required, it makes things a bit more reasonable.

Jupiter is really well placed for northern hemisphere observers right now. It won't always be this good. We'll be spoiled for the next few oppositions, but then it will be poorly placed for us on the other side of its 12 year orbit, like Saturn is for us now. Enjoy it while you can!


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JMac85X
super member


Reged: 09/13/12

Loc: California
Re: DBK 21 Imaging new [Re: GreatGigInTheSky]
      #5591471 - 12/27/12 05:01 PM

That's a good idea, I'm going to throw some bricks down and level them out in the back yard. I have the DX Mount which is pretty heavy. I thought of building a board with wheels on it and have it sit on that so I can just wheel it around instead of picking it up. I usually keep the mount connected to the tripod and lift it up. I'm still pretty young so it doesn't hurt my back or anything. I'll just wait for a good night with a good amount of stars and go from there.

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RedLionNJ
scholastic sledgehammer


Reged: 12/29/09

Loc: Red Lion, NJ, USA
Re: DBK 21 Imaging new [Re: JMac85X]
      #5591500 - 12/27/12 05:22 PM

Someone mentioned FireCapture as an alternative capture tool - I found that seems to suck up less CPU on an underpowered (read: WinXP on a P4) system and generally lets me capture at 60fps and autoguide at the same time. Jupiter will stay centered all night at a ten-meter focal length this way...

Experiment, experiment, experiment. That's the only way to get to where you want to be. Some nights will be much better than others, mainly due to seeing and transparency. You may only get a couple really good nights a year. You're trying to pull out details under a quarter second of arc across - this isn't going to happen every single night you set up, but by making note of what seems to give better results, you'll get there in the end.

Grant


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JoseBorrero
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Reged: 09/04/09

Loc: Puerto Rico Island
Re: DBK 21 Imaging [Re: RedLionNJ]
      #5593220 - 12/28/12 07:44 PM

if you google the imaging source forum you can find that the DMK need an processor updater software in order to improve the fps. http://www.imagingcontrol.com/en_US/downloads/tools/

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JMac85X
super member


Reged: 09/13/12

Loc: California
Re: DBK 21 Imaging new [Re: JoseBorrero]
      #5598989 - 01/01/13 12:50 AM

Somewhat of an exciting night for me, I spent about 45 minutes polar aligning, star aligning and calibrating, bought a bahitov mask for focusing and a recticle eyepiece to help aligning and wow is it easy to just sit in a chair and have the controller in one hand to adjust every minute or two to stay on Jupiter and tweek the settings. I recorded just over a 1000 frames of in my opinion great coloring, but when I go to registax it says the image was shot in black and white. I hit the debraying and the image would go in and out of color so I'm pretty sure I did that part right. What am I doing wrong?

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GreatGigInTheSky
sage


Reged: 02/06/11

Loc: Santa Clara, California
Re: DBK 21 Imaging new [Re: JMac85X]
      #5599060 - 01/01/13 02:16 AM

Assuming you were using IC Capture, what codec were you using when recording? If you look at Adam's screenshot, both the codec and the field above that also has a codec in it, should be set as he's shown it, as Y800. If you have that set, and you're not debayering while recording (you shouldn't see color when recording) then I'm not sure what's going on. I have found in the past that IC Capture was set to a different codec than I thought was set, and it ruined the avi. It's been a while since I've used Registax for stacking and debayering. I only use it for wavelet sharpening and denoising. If you're doing all of the above in IC Capture as described, you might try installing AutoStakkert!2 and seeing if that will work for you.

On the plus side, it sounds like you've got the polar alignment part of this down now, so that's good progress.


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