Seperate exposure settings for plate solving.

[kaymann]

Robin, in most circumstances I would have the typical Light Train:

Antlia Triband RGB Ultra Filter or Optolong L-Pro or..., HyperStar C9.25, EQ mount, ZWO ASI 533MC Pro 30 Seconds Gain 105, latest weekly SC.

Most all times SC PS &/or Sync fails so I then go to gain and shove it up to 200 - 300 and PS/Sync works and then shove the gain back down.

YMMV but I am constantly adjusting gain/exposure to get SC PS working. I do have the additional catalog installed, I do have my precise LATLON entered, I do have the precise FL installed...

[admin]

Hi,

interesting - I can't see an obvious reason why you wouldn't get the option to reduce exposure when running the 'Goto Catalog Target' tool in that situation, as shown below.

Screenshot 2025-01-30 150100.jpg

It's also odd that increasing the gain helps - all that does is boost the brightness of the image (and the noise), basically by a multiplier that comes from the gain increase applied - it doesn't actually collect any extra photons... Now, the reason why this weird is that the SharpSolve code does an automatic stretch on the image that is being plate solved - that automatic stretch would normally be weaker in the case of an image that has already been boosted with extra gain than it would be for the lower gain image, so it's surprising that it makes much difference to the star detection (which is presumably what is causing the failure/success pattern you are seeing).

If you get a chance, grab me a couple of sample frames that fail to solve at lower gain, and the corresponding 'working' ones of the same field at higher gain and I will have a check to see if the auto-stretch or something else in the star detection/plate solving isn't quite working how it should.

cheers,

Robin

[kaymann]

Hi,

interesting - I can't see an obvious reason why you wouldn't get the option to reduce exposure when running the 'Goto Catalog Target' tool in that situation, as shown below.

Screenshot 2025-01-30 150100.jpg

It's also odd that increasing the gain helps - all that does is boost the brightness of the image (and the noise), basically by a multiplier that comes from the gain increase applied - it doesn't actually collect any extra photons... Now, the reason why this weird is that the SharpSolve code does an automatic stretch on the image that is being plate solved - that automatic stretch would normally be weaker in the case of an image that has already been boosted with extra gain than it would be for the lower gain image, so it's surprising that it makes much difference to the star detection (which is presumably what is causing the failure/success pattern you are seeing).

If you get a chance, grab me a couple of sample frames that fail to solve at lower gain, and the corresponding 'working' ones of the same field at higher gain and I will have a check to see if the auto-stretch or something else in the star detection/plate solving isn't quite working how it should.

cheers,

Robin

I have done some experimentation tonight and when selecting an object from the full catalog or from coordinates, that red arrow option pointed out above is not always available. I trying to pin down under which circumstances it disappears... Could you elaborate under which circumstances that option disappears as I have had it completely gone under many recent goto's

[admin]

Hi,

the conditions set up in the code are:

* Exposure is currently more than 5s (not equal to 5, more than)
* A gain control is available and it is numeric (not a drop down list of gains like you get from some DSLR drivers)

there is also a requirement for both the exposure and gain to have an option to be manually controlled rather than being only automatic, but I can't even think of a camera that would have exposure of more than 5s and *not* allow manual control, so that is not really relevant.

cheers,

Robin

[kaymann]

Hi,

the conditions set up in the code are:

* Exposure is currently more than 5s (not equal to 5, more than)
* A gain control is available and it is numeric (not a drop down list of gains like you get from some DSLR drivers)

there is also a requirement for both the exposure and gain to have an option to be manually controlled rather than being only automatic, but I can't even think of a camera that would have exposure of more than 5s and *not* allow manual control, so that is not really relevant.

cheers,

Robin

I think I have the root cause of my difficulties. I start every session with a SC PA using my PoleMaster Camera installed directly into the mounts PA Viewer hole. I connect to the PoleMaster using a profile appropriate to the PM camera and your plate solving requirements. I set the PN very fast and high gain so all adjustments are immediately recognized. After finishing SC PA (ultra accurate as this method seems to give me fantastic tracking, no cone effect(?)), I then use your go to tool to find an object. I switch the camera and profile before the tool button and it seems SC takes a while to realize I have switched and follows your rules above and excludes your red arrow option above. I did experiment being more mindful about the timing of the camera and profile switch before activating your Go To tool and did not once fail to see the Red arrow option. Also for some reason the default for my ASI533MC Pro defaults to 4s which could have something to do with it...

[admin]

Hi,

well the 4s default would definitely stop the option from appearing, but in that case it's OK since it will only reduce the exposure down to 4s anyway, so the change would be minimal.

I can't see anything in the code that would make it sensitive how recently you have opened the camera - it just asks the camera for the current exposure. Definitely an odd one.

cheers,

Robin

[kaymann]

Hi,

well the 4s default would definitely stop the option from appearing, but in that case it's OK since it will only reduce the exposure down to 4s anyway, so the change would be minimal.

I can't see anything in the code that would make it sensitive how recently you have opened the camera - it just asks the camera for the current exposure. Definitely an odd one.

cheers,

Robin

I am sure it is somehow user error. I will be more careful in the future and my uptake on profiles is seriously reducing a lot of my user errors!

[kaymann]

Hi,

well the 4s default would definitely stop the option from appearing, but in that case it's OK since it will only reduce the exposure down to 4s anyway, so the change would be minimal.

I can't see anything in the code that would make it sensitive how recently you have opened the camera - it just asks the camera for the current exposure. Definitely an odd one.

cheers,

Robin

Okay I have it figured out! I was changing my settings to get good numbers for autofocus! and leaving them thinking it would help with plate solving. That habit was killed tonight and instead I reload my profile for EAA/DSO and everything worked perfectly as expected. Question could the procedure for PSing be used in autofocus? Either way all good and loving SC!

[admin]

Hi,

I guess it could be used for autofocus, but I think I would expect most people to set up things for focus to suit the equipment, and messing with the settings automatically would probably be unwelcome. Also, a messed up autofocus run wastes considerable time, but a failed plate solve can be repeated quite quickly.

My approach tends to be to use the 'Exposure/Gain Shift' control when I want reduced exposures for something like focus - as you move it to the left, it reduces exposure but increases gain to compensate, keeping the image brightness roughly constant. Move it from zero to -3 and your exposure is divided by 8, but the gain increased to make the image 8x brighter - net result a noisier but same brightness image. Now do a focus run (or whatever), then move back from -3 to zero and the old exposure/gain are put back.

cheers,

Robin

[kaymann]

Hi,

I guess it could be used for autofocus, but I think I would expect most people to set up things for focus to suit the equipment, and messing with the settings automatically would probably be unwelcome. Also, a messed up autofocus run wastes considerable time, but a failed plate solve can be repeated quite quickly.

My approach tends to be to use the 'Exposure/Gain Shift' control when I want reduced exposures for something like focus - as you move it to the left, it reduces exposure but increases gain to compensate, keeping the image brightness roughly constant. Move it from zero to -3 and your exposure is divided by 8, but the gain increased to make the image 8x brighter - net result a noisier but same brightness image. Now do a focus run (or whatever), then move back from -3 to zero and the old exposure/gain are put back.

cheers,

Robin

Perfect - given that my DSO's are now requiring 90s and above exposures for lights quite a bit too long for AF!