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About cjdawson

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  1. Easiest Widefield shot at dusk that includes the moon. Any camera will do. Auto settings, nothing special needed. hardest High detailed mosaic of a large deep sky object. For example Andromeda Galaxy taken through a 2000mm focal length scope. The detail could be spectacular, however the number of shots, exposure time needed, processing required will make this a challange. cheapest Any photo taken using someone else's gear. you don't pay a thing, can get tuition on how to take the photo and will come away with something reasonable. most expensive High detail imaging of the sun. Solar scopes can get very expensive very quickly. Then you'd need a good camera to go with it as well as the tracking problems etc.
  2. Thanks guys. That makes alot of sense now. I'm going to do some experiments with my camera to see if I can figure out what the offset value should be. So glad that I took the time to find out what this value actually means rather than ending up with clipped images and not knowing it.
  3. Hi all. I've got a question about the settings that are available in the ZWO camera drivers. There's two settings, the gain and the offset. I get that the gain is e-/ADU, or to make it simple with a ZWO 1600-MM-Pro set this value to 139 and it's at unity gain. lowering the gain makes the image darker, and raising the gain makes it brighter - but more noisy. I don't get why I'd want to change this value from the unity value. that's something for another day. I'm happy enough with what the gain is to know how to set it. however, and this is the big question..... offset? What is the offset value for? What is it offsetting? and how do I determine what the values should be?
  4. it's the opposite. It's the temperature of the sensor that is important, only the sensor the rest of the camera can be anything.
  5. It doesn't matter what temperature the camera is, just that the darks are taken at the same temperature that the image was taken. I'll give you an example. when I use a Canon 70D, my camera warms an stays at a temperature (I'm not sure what temp, it doesn't matter) once I finish taking the light frames, I take darks as well, this way they are at the same temp as the light frames. Does mean that I can't image all night long though. With my ZWO ASI1600-MM-Pro I can cool the camera to -20°C. this means that i can take a set of dark frames during the day, meaning that I can take images all night long. As the camera is always cooled to -20°C is keeps things the same.
  6. Darks are never a waste of time. The thing about them though is that you need to make sure that the camera is at the same temperature as when the light frame was taken. This make capturing good darks with a DSLR harder. I managed to create a library of dark images, which did improve the output when I processed an image compared to processing the same without darks. Not sure about your second question as I don't use the drift alignment tool in PHD2. Shouldn't make much difference if you are using an ST-4 or other connection, actually what I understand is that PHD2 was designed to work without the need for an ST-4 connection and will actually work better by controlling the mount directly. That said, if you don't have the option of controlling the mount directly, the ST-4 connection is perfectly fine.
  7. Fair point. In that case, I'd suggest maybe trying a project like the focusser that I'm building. This can run stand alone, so there's no need for a computer. Though to be really blunt, without a big screen, how can you be sure that the focus is spot on?
  8. A simple answer, is that I'm currently building a focusser that uses Bluetooth rather than USB. Power is from the same 12V supply as the scope. So far, I've got it to the point where I'm looking to solve the problem of mounting the motor on the scope. Just need to do that and then figure out how to tidy up the connections, then it's work complete. Bluetooth control will work over a short distance - I'm planning on about 3-5 meters, as my capturing laptop will be near the scope. I can control that via Remote desktop using a wifi connection.
  9. Erm, silly question but.... for a Canon camera, why not simply use the focuser built into the lens itself? Software like backyard EOS will let you drive the focusser through software.
  10. Just taken delivery of a complete set of belts of my 4:1 ratio pully. At first offering up, looks like I’ll be using a 120mm belt, possibly a 130mm. Either way. Just need to make up the bracket so that I can mount the motor near the focusser. Still not 100% sure how the bracket will look. This project is getting closer
  11. I prefer to have my soldering goggles set to 2.5X it gives a great blow up of what I’m going and I can see what I’m doing better than when I was a kid. There’s no eye strain and with the blown up image of my work piece i can see to be able to solder pins next to each other without problem. For telescope work, erm, er, been so long since I put an eyepiece on my telescope, not sure what my camera’s magnification is.
  12. I personally cannot support deep sky dad. Not sure if things have been resolve, but check out this thread... Turns out that Deep Sky Dad has been accused of plagerism. I don't want to restart the debate / argument that hijacked my thread, just wanted to highlight that things are not all as it seems. My opinion is to go for one of these https://sourceforge.net/projects/arduinoascomfocuserpro2diy/ as it's well supported by Robert, he's done a fantastic job.
  13. Cable management is always a constant battle with any scope. This is something that I've had as an on going project for since I first decided to do more with my scope than run from the internal batteries (I did that once, never again) The main problems remain rather constant - USB Cable for guide camera USB Cable for Imaging camera USB Cable for filter wheel Power for OTA Power for Imaging camera (it's a cooled ZWO) Power for focusser (No need for USB as I've gone bluetooth to cut down a cable) 2 Dew heaters. This is pretty much all the cabling that I want at the scope. But being handy with a soldering Iron has it's advantages. here's how I've solve the problem for now... Usb Cable for Guide Camera - 5m lindy (usb 2), to powered usb 3 hub Usb Cable for Imaging Camera - 5m lindy (usb 3) to powered usb 3 HUB USB Cable for Filter wheel - 50cm ZWO cable from filter wheel to camera's built in hub. This means that there's 2 USB cables coming from my scope to the Hub. I could have used the second port on the ZWO For the guide camera, however I'm not because of other factors, so this makes my life much easier. Power and dew control is another problem all together. For this I build an all purpose control box. This allows me to run everything at the scope using a single cable. the control box as a 12v input. then inside has 2 PWM's for the dew heaters, i.e. 2 channels. Then there's 12v for the scope and 12v for other things also there's a 5v cable too. Where practical, I've made the ground common, so in all I'm doing this with only a few wires. The best part is that there's only one cable that needs to plug into the mount to power everything. All in all, it's as tidy as I can make it for a portable solution.
  14. Hiya. I'm also getting myself up and running with LRGB imaging using a ZWO ASI1600MM-Pro. Everything I understand on this subject is that there is no easy answer. That said, I've got a plan. Turns out there's an idea exposure time statistic in SGPro, I'm not expecting this to be the perfect answer by any means. As an experiment, I'm going to take a sub next time I'm out, and will see what this statistic says. From there, I'll adjust the sub time and see what happens. I'm going to try this in L only to begin with, then if it works well, I'll try the same for each of the other filters on the same target. If it all works out, then I'll should have some idea of the ratio of exposure times for each filter (yes, I know this is nieve, it's a start and not ment to be a complete answer) From there on out, I'll have a starting point to tweak from.
  15. Spurred on by getting the circuit working, my attention has now switch to the mounting Here's my focus controller in all it's glory. There's no access to the USB port, as I'll be connecting via bluetooth. On the left side of the box is a 2.1mm DC power socket, and a GX16-7 which is to connect both the motor and the temperature probe. I did make up a 5 meter cable, but the temp probe didn't like it. I built up a shorter 1.5 meter cable and everything is working great. My attention has now shifted from the controller box, so the telescope side. The plan is to mount the motor so that the base is away from the user, and the pully is in line. Here's the large gear wheel seated on the focus knob. And the only points I have to mount to the scope is around the focusser itself My plan is to drill a 22mm hole in a piece of aluminium then drill smaller holes to make a bracket that will fit snug over the focus knob, this will then be held to the scope by the existing three screws. The piece of alu, will be bent to form an L-Bracket, to which the motor mount can attach. This should bring everything in line and make for a neat mounting.
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