There's a process in astronomy called dithering and there's an expression that goes dither or die. What it means is that when we're guiding and tracking on a star and we're taking these long exposures of space, even when you stack the image afterwards, you can still get lines and glow and bias noise in your images and that non-random noise proliferates through your image unless you now what dithering is is when you have the telescope lined up at a star and it's tracking that star and moving across the sky. In between each exposure it will move the telescope just slightly up, down, left, right in any random direction so that the noise that you have in your sensor is sort of smudged around. So instead of that hot pixel being there every single time on every frame, that hot pixel moves around slightly. The effect of that is that when you go to average and stack your images, it averages those hot pixels away and in fact you can actually do away with ducks altogether by using dithering and some people do this. However, I would suggest that it's good to do dithering and guiding and frame calibration because that gives you the best result. So stick around, I'll show you a little bit more about dithering. My name is Dylan O'Donnell and you're watching Star Stuff. Now it's the serenity. So there's my guide camera there and let's connect it directly to the USB hub which is then connected to the computer and my hand controller is connected via USB to the same USB hub which is then connected to the computer. A lot of people were really confused about that setup and how I was guiding without the ST4 port which you should view in my PhD to guiding video. Don't use the ST4 port. Dithering will still work with it but I'm just giving you that reminder that you should be connecting your mount directly to your computer. Then using the guide camera's output to control the movement of the mount movement of the scope by ASCOM. That's all with the best option. Now on the PhD to side of things all you need to do is go into the tools menu and click that enable server. That creates a little local server on the computer that you then connect your acquisition software to to do the dithering. So it can send those dithering commands to PhD to. So for example if I was using Nebulosity here is the PhD link window down here and we just hit connect and then you want to set the dither. I usually go about a medium dither and settle at one and that will move the telescope around a little bit and then settle down the guiding again and then it will start taking the next exposure. So it creates a little pause in between each image. It doesn't take too long though and then it just keeps capturing. How's the serenity? Now here's the same thing in sequence generator pro in the control panel under the guiding settings. You can see that I've got dither tipped, medium dither, every frame, settle at about that one mark. It connects through to PhD to and handles everything in the background. That's all you need to do. So PhD to actually has a log viewer that you can download for Windows or Mac which I highly recommend. So if it's from an unidentified developer which is crazy, it's by Andy. Andy Galasso, I know him, he's identified. It's a program that's you open up your PhD guide logs. If you've got any line around you can take a look at. I'll just select one at random here. Okay so this gives you a lot of detailed information about your guide settings. The total error wasn't so good that night, one hour second. Anyway this illustrates what I wanted to show you that while it's taking the exposure and this space here then it has a dither. So it shows you how much it did this by each time. Oh my god it's so noisy out there. Anyway it's a full moon at the moment. So the moon is not visible during the day but it is big and bright during the night and it's the biggest super moon of the year and you know what that means. Absolutely nothing. It actually means I'm not going to be imaging tonight. So here's an example of an image that hasn't had dithering and you can see that even though I've calibrated this image with a bad pixel map the readout noise and the line noise from the sensor readout is really visible and here is the same target with the same telescope, same camera but with dithering. So you can see that the difference is significant. To illustrate this effect what I've done is I've created a secret message in this image and then I've used the ad noise to add some just to just add some noise to it but what I'm going to do is shift the noise up down left and right and save off 10 versions of this with the noise scattered around and then we'll stack it and see if we can read the message. So now I'll just stack these images and because I've simulated a dither it reveals so you can see how it's dealt with that noise and we can see the message loud and clear. Dithering is super easy. Once it's set up and once you click those buttons pretty much don't have to worry about it again. In the velocity always had to go and hit that connect button but in sequence generator pro it just works every time you open the program. So once it's set up it's set up. I do have a little bit of quicker strut in me news. The NEED conference is coming up so if you're in America you should get down to that because it looks like an amazing conference especially if you're into gear and new stuff and who isn't. If you're in Australia, Bintel is running its Karina challenge until May 1st. This is the first time we've done this but if you submit your images of the Karina Nebula which is over us in the skies in the southern hemisphere you can win some store credit and get yourself some new stuff and if you're like me you love Karina. Karina is the biggest Nebula in the southern hemisphere it's much bigger than Orion and it really is the jewel of our southern skies so get a chance. Do point your telescope in that direction. I do intend to do the Brasa 8 review. I just have to get some adapters to make it work with the Hyperdrawer filter system. This is sort of non-standard and it's not meant to work that way but if it does work this way the Brasa 8 is a really cheap Narrowband tool especially with the ZWO 1600 mm camera that I've been testing as well so I'll let you know how that goes. And one final little tidbit was that there was a comment left on my Ascom video saying that Ascom looks like it's being ported to other platforms which may mean that Ascom gets ported to Mac and Linux. Now if this happens this is huge this makes everything easier for hardware vendors and everything will be cross platform compatible. I really hope that the Ascom guys work this one out because that's huge but that's it so remember everything is meaningless and we're all going to die.