7 replies to this topic

[flamidey]

Hey folks,

Forgive the moon imagining 101 question but I couldn't find any answer to my problem.

 

I am trying myself at moon photography. My setup is an 8" Newtonian with an ASI294MC. Probably not the best combo ever but that's what I have and my friend really likes pics of the moon.

 

I was lucky on my first try and framed the moon more or less by accident. Luck soon faded away and now I'm facing my lack of technique hen it comes to putting the sky's biggest bright (well, sun excepted) object in my field of view.

 

I use NINA / Sharpcap and Firecapture, along with Cartes du Ciel.

 

I do my PA religiously and get under 1 arcmin error.

 

I set tracking to Lunar in EQMOD, then I just ask CdC to slew to the moon and... nothing. And a pretty big nothing at that. Same with Stellarium or copy paste RA/DEC from Sky Safari or Orbitals in NINA's framing.

 

I also tried the spiral in EQAscom, or just slewing here and there, hoping to get a glimpse of the super bright light but nothing.

 

I am pretty sure you guys have a way of solving this problem, at least a technique so I don't need one hour to find the Moon... 

 

Thanks for any tips.

[MJB]

I think with your setup I would just use the visual finder that I'm assuming is attached to the Newtonian. Also assuming your tracking is engaged. Your exposures will likely be on the order of 1/250 of a second, so even tracking is not all that critical just yet. I would remove CdC and slewing issues associated with that from the problem, and treat that as a separately debuggable task. If the primary task is to get some shots of the moon, I'd point and slew manually with a finder first. 

Edited by MJB, 14 May 2022 - 06:22 PM.

[flamidey]

Thanks for the suggestion!

I could add a second finder as the one I have is used for guiding.

[Spaceman 56]

you have a complex set up for something as large as the moon.

 

you just need to look through a Red Dot finder to get semi close. then use Synscan hand controller to centre the moon in your Visual finderscope.

 

once you find it in the visual finder, you should see it in the 8 inch newtonian.

 

then adjust the image centre in the Newt until its centre, and choose Lunar rate in the hand controller, and not Sideral.

 

you will need to focus the camera as well.

 

another less complex way to do all this is to just get down low and look up the outside edge of your OTA.

 

I can do that with my 80mm refractor and it works.

 

also there is no need to guide on the moon, if you are just taking single shots.

 

Good luck Flamidy.  

[ghilios]

Chances are your pointing model is off. I suggest starting the session with a plate solve + sync after building a pointing model. Then Orbitals should get you dead center.

[Lacaille]

 

I am trying myself at moon photography. My setup is an 8" Newtonian with an ASI294MC. Probably not the best combo ever but that's what I have and my friend really likes pics of the moon.

 

I was lucky on my first try and framed the moon more or less by accident. Luck soon faded away and now I'm facing my lack of technique hen it comes to putting the sky's biggest bright (well, sun excepted) object in my field of view.

 

I use NINA / Sharpcap and Firecapture, along with Cartes du Ciel.

 

I do my PA religiously and get under 1 arcmin error.

 

I set tracking to Lunar in EQMOD, then I just ask CdC to slew to the moon and... nothing. And a pretty big nothing at that. Same with Stellarium or copy paste RA/DEC from Sky Safari or Orbitals in NINA's framing.

 

I also tried the spiral in EQAscom, or just slewing here and there, hoping to get a glimpse of the super bright light but nothing.

 

I am pretty sure you guys have a way of solving this problem, at least a technique so I don't need one hour to find the Moon... 

 

Thanks for any tips.

Hmm.  I am a great believer in having a nice RACI finder perfectly centred on the capture sensor. It does help eliminate other sources of error such as not having the camera plugged in, leaving the objective lens cap on etc. (All of which I have done btw!). So I would recommend getting that part sorted. 

 

But I do note that you seem to have good alignment of the mount and yet you are getting nothing, even after slewing around. I checked the FOV with that camera and (what I think would be) the specs of your scope, using Stellarium,  and it would seem that the full moon should pretty much fill the full sensor. 

 

I am not sure what capture software you are using. I use the latest version of Firecapture and will work through some options based on my experience with that excellent software. 

 

1. Can you confirm that you have the camera properly connected to the laptop, so that if you wave the camera around towards a bright light source you see a reaction on the screen? Occasionally I have found that the connection does not form, so superficially all is connected, but there is actually no signal being received. But this is unlikely, so let's move on to the next suggestion.

 

2. Have you accidentally selected a small region of interest on the sensor? When trying to place the target, ideally you should use the whole sensor.  When you select the whole sensor, reduce the zoom to make sure the whole sensor is on your laptop screen. It is very easy to find you are looking at only part of the sensor if you don't reduce it to about 25-40% zoom.

 

3. Assuming you are using the whole sensor, crank up the gain and the exposure time so, as you slew around groping for the target, you will see the histogram respond if you get anywhere near it.  

 

4.  You may have adjusted the focal length since you last saw the moon - if you are out of focus the image will be very, very dim - this is where No 3 above can help.

 

I hope you make progress. I think that setup will be excellent for lovely moon images. I do a lot of close-ups myself, but I admire large field views. You could readily do a nice mosaic of the whole moon with just a few images using your gear.

 

Mark

Edited by Lacaille, 14 May 2022 - 07:20 PM.

[flamidey]

Chances are your pointing model is off. I suggest starting the session with a plate solve + sync after building a pointing model. Then Orbitals should get you dead center.

I would have thought as well but I did platesolve successfully before hand. Maybe I have something off in my parameters.

[flamidey]

Hmm.  I am a great believer in having a nice RACI finder perfectly centred on the capture sensor. It does help eliminate other sources of error such as not having the camera plugged in, leaving the objective lens cap on etc. (All of which I have done btw!). So I would recommend getting that part sorted.

 

 

I will look into that solution, thanks.

 

But I do note that you seem to have good alignment of the mount and yet you are getting nothing, even after slewing around. I checked the FOV with that camera and (what I think would be) the specs of your scope, using Stellarium,  and it would seem that the full moon should pretty much fill the full sensor.

 

I am not sure what capture software you are using. I use the latest version of Firecapture and will work through some options based on my experience with that excellent software.

 

1. Can you confirm that you have the camera properly connected to the laptop, so that if you wave the camera around towards a bright light source you see a reaction on the screen? Occasionally I have found that the connection does not form, so superficially all is connected, but there is actually no signal being received. But this is unlikely, so let's move on to the next suggestion.

 

 

Definitely. Imaging works fine, it's really just the search that is a pain.

 

2. Have you accidentally selected a small region of interest on the sensor? When trying to place the target, ideally you should use the whole sensor.  When you select the whole sensor, reduce the zoom to make sure the whole sensor is on your laptop screen. It is very easy to find you are looking at only part of the sensor if you don't reduce it to about 25-40% zoom.

 

 

I am using NINA to frame the Moon, with no ROI.

 

3. Assuming you are using the whole sensor, crank up the gain and the exposure time so, as you slew around groping for the target, you will see the histogram respond if you get anywhere near it. 

 

 

I will try that, thanks.

 

4.  You may have adjusted the focal length since you last saw the moon - if you are out of focus the image will be very, very dim - this is where No 3 above can help.

 

 

No change in focal length; my focus would be on the stars but i am confident at f5 I would still have a huge flood of light when point at the moon with 1s exposures.

 

I hope you make progress. I think that setup will be excellent for lovely moon images. I do a lot of close-ups myself, but I admire large field views. You could readily do a nice mosaic of the whole moon with just a few images using your gear.

 

 

Thanks a lot, I will definitely persevere and try the mosaic approach when I have mastered the basics.