Problems with a Meade LPI-G mono

StuartT
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Problems with a Meade LPI-G mono

#1

Post by StuartT »

I am trying to use my Meade LPI-G mono in SharpCap.

In the 'cameras' menu, I'm selecting MeadeCam. I adjust the exposure level to get a mid-histo peak

I run a capture of say 250 frames in SER format

But when I open the SER in Autostakkert, it's completely black for the whole duration of the movie.

What am I doing wrong?

There are some other odd things too. In 'Image Controls' I can't seem to set the gain < 100
and when I reduce the resolution from 1280x960 down to 640x480 the frame rate stays the same. Shouldn't it increase?
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Re: Problems with a Meade LPI-G mono

#2

Post by admin »

Hi Stuart,

a lot depends on how you are connecting to the camera - I am guessing that you are using a DirectShow driver, but maybe it is ASCOM.

Do you see the same thing with a black image if you save a single frame to PNG or FITS? If so, please can you share one such image and the camera settings file so I can see what is going on.

As to the frame rate rising for smaller resolutions, that can happen with some cameras, but it depends on a number of things - first the exposure must be short enough (ie you cannot get more than 10fps for 100ms exposures). Also the camera driver developers need to have written the code to support this.

Finally, on the gain, minimum/maximum values will come from the DirectShow driver (thinking about this, I am now fairly sure you are using DirectShow). It could be that these cameras are working like Altair cameras, where minimum gain is 100, 200 gain is twice as bright, and so on.

cheers,

Robin
StuartT
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Re: Problems with a Meade LPI-G mono

#3

Post by StuartT »

Thanks Robin

Firstly, yes I am using the Direct Show driver from Meade's Sky Capture suite.

Secondly, I just tried taking a snapshot in both PNG and JPG format and those are fine - i.e. showing an image correctly (image and camera settings attached)

Thirdly, understood about frame rate and resolution (I'm just used to ZWO cameras where reducing ROI increases frame rate)

Thanks
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Re: Problems with a Meade LPI-G mono

#4

Post by admin »

Hi,

ok, all of that looks reasonable. Any chance you can share a very short (2 or 3 frames) SER file showing the problem you are seeing there. Also, what SER viewer are you using?

cheers,

Robin
StuartT
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Re: Problems with a Meade LPI-G mono

#5

Post by StuartT »

The problem was when I brought the SER files into Autostakkert!3 - they were just showing as black.

It didn't occur to me to try them in a SER viewer (I didn't even know there was such a thing). But I have installed one now and the files do indeed play normally. So it's not a problem with SharpCap.

I am puzzled as to why they are showing as black in AS!3, but that's not your problem ;)
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Re: Problems with a Meade LPI-G mono

#6

Post by admin »

Hi,

Ok, that's interesting... I would still be interested to look at a sample SER file to see if perhaps I am doing something when writing the SER that is upsetting AS!3. I just checked AS!3 with a SER saved from SharpCap using a webcam and it all looked fine to me though...

cheers,

Robin
StuartT
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Re: Problems with a Meade LPI-G mono

#7

Post by StuartT »

Ok, it won't let me upload a .SER file to this reply, but here is a gDrive link to a short .SER file for you to look at

https://drive.google.com/file/d/1kAKFlP ... sp=sharing
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Re: Problems with a Meade LPI-G mono

#8

Post by admin »

Hi Stuart,

that one looks ok to me in AS!3 (3.1.4). You haven't made changes to AS!3 settings that might be causing this - for instance the scaling settings I have circled below?

cheers

Robin
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StuartT
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Re: Problems with a Meade LPI-G mono

#9

Post by StuartT »

These are my settings in AS!3
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Re: Problems with a Meade LPI-G mono

#10

Post by admin »

Hi,

Ok, so you need to re-tick the 'auto' checkbox under scaling. At the moment, you have turned auto off and set 16 bit data in AS!3. The SER file is only 8 bit (0..255), so interpreting it as 16 bit (0..65535) is leaving everything as 'black or so close to it that you can't tell the difference'

cheers,

Robin
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