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Sharpcap Lunar Primer

PostPosted: Sat Jan 22, 2011 2:29 am
by Dion
This one is intended for the total beginner, to introduce sharpcap and to get you on the way to your first image. In the video, I state there is a way to tell if your switch is not in the 'non lx' position in sharpcap. If your 'exposure' slider doesn't work in sharpcap, chances are you have the switch in LX mode as exposure is the same as shutter speed, therefore the camera is looking for shutter speed control from your serial cable.


Re: Sharpcap Lunar Primer

PostPosted: Wed Jan 26, 2011 7:41 pm
by Dion
it was pointed out to me that people who are hard of hearing may have trouble with videos that describe settings, hopefully i've fixed that in the new LX tutorial. However for this one, a huge massive humongous thanks goes to Jim who has typed up a transcript of this tutorial along with a pilot style checklist that can be copy/pasted and printed out and laminated, the pilot list was Jims idea and a brilliant one it was too! :ymapplause:


FULL TRANSCRIPT

“Hello again, in this tutorial we are going to go right back to basics in that we are going to take an image of the moon, using a webcam and the Sharpcap software. Now obviously I’m going to have to do it virtually because I haven’t got a telescope in here and I haven’t got the moon. So there will be a couple of props involved but everything will still follow, and you will understand exactly what’s going on.

The first thing we are going to need is the webcam, this is one of my long exposure modified webcams, the main difference is, because I am doing this virtually, I have the normal lens screwed into it, where you would have your adaptor screwed in and the camera connected up to a telescope. Now bear in mind for this tutorial that you need to have your switch on the bottom in “non LX” mode, that’s important because a few people have made exactly that mistake, they have got the switch in the wrong position, so you need to be in “non LX” mode. Now, in Sharpcap there is a way to check you are in “non LX” mode which we will cover shortly.

1. Another prop that I’m going to be using is an image of the moon, because we don’t actually have the moon here, and that’s about it for this part, so you will be wanting to have your camera plugged into your USB port. You don’t need your serial port plugged in because we are not doing long exposure, we are just doing normal webcam moon captures using Sharpcap. - And so lets go on to the next bit

OK we’ve now got our Sharpcap programme launched and we are going to go through, methodically, each setting. Ignore for the moment what it shows in your preview screen, we will work through that as we go along.

The first thing you want to be doing is to go upto and click FILE, and set your capture folder, now this is the folder that its going to save your AVI’s to. I just prefer to make a folder on my desktop and call it say “Moon”, or just give it the date so I can keep track of exactly where I am. So that’s the first thing make sure you set up your capture folder.

The next thing is Cameras, and here I’m going to select Phillps SPC900NC because that’s obviously the camera that I am using. If you are using a different sort of camera then just choose your camera from the cameras list.

Next we are going to go to options, now on options you want to be looking at video capture filter. What that is, is your driver settings for your camera, and there are a couple of things that you want to make sure are set in this. Now for me its Flicker less image is OFF, Face Tracking is OFF, digital zoom is OFF, picture enhancer is OFF. Now depending on what driver you have installed you will have different settings, but these, if you like are just cosmetic settings that you don’t want and they will interfere with your image so all of them should be off or disabled.

In your picture settings your frame rate should be looking at 10 Frames per second. That’s the normal capture rate for doing astro imaging.

This is very important, Auto exposure should be OFF, the reason being if you have auto exposure turned on, every time you try to do some settings in Sharpcap, the camera will try to compensate and mess your settings up. So Auto exposure always should be off.

Shutter speed you can ignore as you wont be able to set it in Sharpcap.

Auto wide balance, this wants to be on really, it just helps things along so don’t disable that, it’s the only one that should be on really.

Brightness, contrast and saturation settings, again just ignore them really. Black and white you want off because you are not taking mono images. Backlight compensation again turn that off, mirror you don’t want that again turn that off.

Then there is an audio tab, which again you don’t need because we are not really interested in audio at this point.

So that’s our camera now basically set up. Ignore completely what it shows in the preview screen for the moment because we still have not finished putting in the proper settings in and how we want everything.

So next we are going to move over to this section which is the Sharpcap settings, now the first thing to be doing is looking at colour space compression now for this you want it YUY2. Frame rate here its saying 30 frames, we don’t want that we actually want 10 frames per second, and stick with 10 frames per second for the time being. When conditions are absolutely perfect you can go to five frames per second, but as a default, keep at 10 frames per second.

Now your resolution, for this you want the maximum for this camera, which for this one is 640 x 480 so we are set for 640 x 480 and you will now see that the preview screen has grown.

Now we are going to ignore the top couple of settings for the moment which are Exposure and Gain, but I want you have a look at these ones below.
Now the backlight compensation should be all the way to the left, because we don’t want it
Colour enable, that should be all the way to the right, that is basically an on and off switch more than anything else, its either in colour or its not, so that again is all the way to the right.
Your Gamma, I always prefer to leave this right in the middle, so keep that right in the middle, later on you can try messing about and trying different settings, but for the time being leave your gamma right in the middle.

Now Saturation, I actually prefer to have that very, very slightly over to the right, it just adds a little bit more colour to your images, and helps a bit when you get to the processing stage. You know it just gives me a little bit more to work with, I’m just happier with the saturation over that little bit.

Contrast and brightness, again I leave at 50% I don’t bother touching those at all.

Now the next thing we are going to want to do is point our telescope at our image, which in this case is going to be the Moon. As you can see we have a very blurred image of the moon there, also its dark.

Firstly, What I do, is I put the gain up to the middle, so 50% like so, and next I use my exposure control, and its almost like a course adjustment on your exposure, now don’t try and copy these settings on your own image, find your own settings, because obviously, with different light levels, I’m actually doing this in my office, so my light levels are completely different than they will be in your case. But when I adjust this what I like to do is to get it just under the level of brightness than I would like to see on my screen, which in this case with it all the way up is it, its just under.

Next is the gain control, and we are using this as a fine control more than any thing else, just take it up until you have got a modicum of brightness there. Now we are going to come back to these in a moment, because as you can see we are out of focus.

Now with all your imaging focus this the single most important thing to get right. Spend 5 minutes on it, spend 10 minutes on it, spend half an hour on it even, but your focus is very, very important. Bad focus you just cant fix later, your screwed basically so take your time with your focusing just to get it right. So that’s what we are going to do next, we are just going to focus up on the moon. And there we are, we are nicely focused up on our moon.

The next stage we come back now to our gain, and we just tweak it, that little bit, just to get something that we are happy with, we are way too bright, but tweak it to something that you are happy with. We want to be looking at these white areas, if I just tweak the gain up a little bit, these white areas are washed down, you have too much gain their, so if I just back that gain off a little bit, like so, until those white areas are just nice, you can nicely see them, don’t start thinking that the dark areas will be too dark in your image. It’s a lot easier to improve a dark a image than it is to improve a washed out image. Because basically when its washed out you have lost that detail, its just burnt out, but if you are under gain a little bit, that detail is still there it just needs bringing up, its not been burnt out. So that I would say is about right at that point.

Now what we can do is, we can actually start taking a capture. So what we would do at this point is move to start capture and just click on there. It will ask you to set a capture limit, this is actually a really good feature of Sharpcap. I prefer to use number of frames for my captures. You will alter your number of frames for different subjects and I will give a brief explanation as for why. for the moon I use about 2000 frames, that is just a good number of frames to use for the moon.

Now if your imaging something like Jupiter, it spins at quite a fast rate and if you take too many frames or you take too long you are going to get what is called rotation errors, which means because that planet is actually rotating fairly fast in the case of Jupiter, its going to have rotated a little bit between your first one and your second one. So if you are imaging Jupiter in that case I would use about 1300 frames. Any way as we said we are on the moon with this one, so as we said 2000 frames.

Once we have selected 2000 just click ok, that’s it Sharpcap will now start taking our frames. As you can see on the bottom right it says frames left, and it’s counting down at this point if you are confident enough to leave your scope tracking you can go inside and put the kettle on or do anything you want to really. You don’t have to sit there freezing cold watching this count down. That’s basically it, once it’s done its 2000 it will tell you how its done, just click ok and you will have your AVI there. Next I’m going to show you a typical AVI take up from Sharpcap, just to show you what you should be looking for on your screen and how you should be looking.

Right this is a live capture using Sharpcap with the webcam connected to the telescope and every thing. It just gives you an overall idea of the sort of image you should be seeing and the lighting settings and everything and the level of contrast. That is taken on a particularly good night so the quality is rather good, but there is no reason why you shouldn’t be expecting to get that sort of image quality on your captures. That’s about it really, once again, thanks for watching.

Re: Sharpcap Lunar Primer

PostPosted: Wed Jan 26, 2011 7:44 pm
by Dion
Pilot Checklist – Webcam Moon Imaging



HARDWARE

1. Webcam Switch to Non LX Mode [ ]
2. Camera Plugged into USB port [ ]
3. Camera Serial port unplugged [ ]

CAMERA

4. Sharpcap Running [ ]
5. File > set capture folder [ ]
6. Cameras > SPC900NC [ ]

7. Options >Video capture filter
Flickerless image > OFF [ ]
Face Tracking > OFF [ ]
Digital Zoom > OFF [ ]
Picture Enhancer > OFF [ ]

8. Picture Settings
Frame Rate 10FPS [ ]
Auto Exposure OFF [ ]
Auto White Balance ON [ ]
Black & White OFF [ ]
Back light compensation OFF [ ]
Mirror OFF [ ]

SHARPCAP SETTINGS

9. Colour space compression YUY2 [ ]
10. Frame Rate 10FPS [ ]
11. Resolution 640 x 480 [ ]
12. Back Light compensation FULL LEFT [ ]
13. Colour Enable FULL RIGHT [ ]
14. Gamma CENTRE [ ]
15. Saturation JUST RIGHT OF CENTRE [ ]
16. Contrast CENTRE [ ]
17. Brightness CENTRE [ ]

IMAGE SETTINGS

18. Scope pointing at moon [ ]
19. Gain CENTRE [ ]
20. Exposure SLIGHTLY DARK IMAGE [ ]
21. Gain BRIGHTNESS ABOUT RIGHT [ ]
22. Focus IN FOCUS [ ]
23. Gain (use light parts of moon NICE IMAGE [ ]
24. Start Capture [ ]
25. Number of frames 2000 [ ]
26. Click OK [ ]
27. Kettle ON [ ]