Newbie: Will a Canon 1000D work with SharpCap?

cavallino
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Newbie: Will a Canon 1000D work with SharpCap?

Post by cavallino »

Hello,

I would like to use SharpCap with my Canon 1000D later. I installed ASCOM, the ASCOM.DSLR Driver and ASCOMDSLRTest utility and as far as I can see, most parts of SharpCap are working. However, when I try to do a Sensor Analysis I get two problems:

1) Error message: "The exposure time required is shorter than the minimum exposure value - Sensor Analysis stopped! Restart with lower light levels." I am sure, this is just a problem with settings or the picture I take (no stars, just one LED in a dark room, it is snowing at my place...)

2) Message "Camera with Dropdown selection for gain control are not supported, sorry." Does that mean, SharpCap will not properly work with my Canon 1000D?

I need the results of the sensor analysis to use an Exposure Calculator from Gibraltar. Otherwise I have no clue what exposure settings (time, iso...) to select for DSO-Imaging.
http://www.gibastrosoc.org/sections/ast ... calculator

I'd be very happy if someone could post some Default values for my Canon 1000D, so that I can Play around with the calculator:
Gain Value e/ADU Read Noise (e) Full Well (e) Relative Gain Rel. Gain (db) Dynamic Range (Stops)

BTW: The Manual/description of ASCOMDSLRTest should mention, that the shutter must not be set to manual (at least for a Canon 1000D). Test photos work only if it is set to the Default value (not Manual to avoid shaking).

Any help would be greatly appreciated. But also pls. let me know, if it does not make sense using a 1000D with SharpCap.

Thank you
arno
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Re: Newbie: Will a Canon 1000D work with SharpCap?

Post by admin »

Hi,

please try using the SharpCap 3.3 beta to run the analysis on your camera

viewtopic.php?f=38&t=3121
https://www.sharpcap.co.uk/sharpcap/sha ... s/3-3-beta

This has better support for dealing with DSLR cameras (including the ability to turn off live mode so that images are not being taken all the time). It should also cope better with the sensor analysis.

The figures I have seen for other models in the Canon range indicate very high read noises at low ISO (15 at 100 ISO seems typical). By 800 ISO the levels are dropping down to values that might be more typical of Astro cameras (3-6e). I'm surprised by the very high values at low ISO, but they strongly indicate not to use DLSR cameras for astrophotography at low ISO.

Robin
cavallino
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Re: Newbie: Will a Canon 1000D work with SharpCap?

Post by cavallino »

Thank you Robin,

3.3 Beta is working better.

However, I connot convince Sensor Analysis to use any other value than 2.2 sec exposure time. I can change the ISO setting on the camera and within SharpCap and the picture changes accordingly. If I change exposure time, it will be set back to 2.2 sec, no matter if I do it on the camera or in Quick Pick or in the field "Exposure", LX Mode on or off. It does not matter if I turn on lights or not. Pls. have a look at the screenshot. I do not know where the 2.2sec are set but they do not depend on how much light there is or what ISO setting I use.

Edit: On stupid question, please: What is a 65% peak? (% of what?)

Something else: When I pressed the "Cancel" button in Sensor Analysis Sharp Cap crashed twice, did not response anymore. (Win7 laptop) Maybe it happened because I pressed cancel during exposure time. I filed the problem but I am not sure if it went through correctly. I can reproduce it.

Concerning ISO value: I found very, very strong advice to use ISO 800 with a Canon 1000D, too. I recently saw one post saying something like "don't trust anyone, use ISO 400 or less to get less noise...".

regards
arno
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Re: Newbie: Will a Canon 1000D work with SharpCap?

Post by admin »

Hi,

thanks for sharing the screenshot – that makes it easy to spot what the problem is. If you look at the histogram on the right-hand side you can see that there is no signal beyond about 25% of the way across. This is going to be caused by the Ascom driver giving the wrong maximum ADU value back to SharpCap, which in turn makes SharpCap think the images underexposed.

If you go into the settings of the Ascom DSLR driver, there is an option for 'Max ADU override' - enable this and set a lower value, one that makes the histogram go almost all the way to the right-hand side and hopefully things should work a lot better! You may need to close and reopen the camera for SharpCap to take any notice of the change of this setting (not sure about this...)

Cheers, Robin
cavallino
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Re: Newbie: Will a Canon 1000D work with SharpCap?

Post by cavallino »

Ok, reducing the value max ADU to around 4000 (from default 14605) worked. I could start the sensor analysis.

When it finished, I saw the results table for a few seconds, however, there where no values in the table. Plus a statement for copy/paste in the pro version. Then the table disappeared. Is the result stored somewhere?
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Re: Newbie: Will a Canon 1000D work with SharpCap?

Post by admin »

Hi,

there will be a file in the folder

C:\Users\<your windows user name>\AppData\Roaming\SharpCap\SensorCharacteristics

it's not going to be readable by you, but I can extract the data from it - post that file here (probably need to put it in a .zip file for the forums to allow it) or email it to me (there's a contact us at the bottom of the page).

thanks,

Robin
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Re: Newbie: Will a Canon 1000D work with SharpCap?

Post by cavallino »

pls. have a look at the attachment (*.zip)
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ASCOM Camera Driver for DSLR [Canon EOS 1000D]~RAW16.zip
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Re: Newbie: Will a Canon 1000D work with SharpCap?

Post by admin »

Hi,

thanks for the file - unfortunately it looks like there was a problem measuring the relative gain values of the different ISO levels, which has led to the data being invalid (lots of things that should have measurements are 0.0 :( ).

If you have the SharpCap log of the sensor analysis run, please post it here (it will be one of the largest log files in the log directory - see https://docs.sharpcap.co.uk/3.2/29_BugsCrashes.htm for details of how to find the log files). Hopefully that will help explain what went wrong.

thanks,

Robin
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Re: Newbie: Will a Canon 1000D work with SharpCap?

Post by cavallino »

see the logfiles enclosed! I did it twice, the first time I ran out of battery close to the end, the second one finished without data
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Re: Newbie: Will a Canon 1000D work with SharpCap?

Post by admin »

Hi,

I'm afraid that the shorter of the two logs (from about 23:17 to 23:27) seems to cover an attempt where the illumination was too dim (SharpCap increases the exposure to 2.2s, but it is still too dim).

The second longer log (23:28 to just after midnight) seems to run through successfully once and then start again at just after midnight, then at 00:08 the camera is disconnected.

So far I've not seen anything that looks bad in the second log :(

I think I will have to add some more diagnostic info to the logs to sort this out...

cheers,

Robin
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