APT live view problem...Help please!

[StargeezerTim]

Hi,

I am familiarising myself with APT by using it to control my DSLR (canon 550d), with lens attached, indoors, in artificial light.

I am setting up as per instructions (M, bulb setting, manual focus on lens) and am able to connect camera and get live view and take single shots and plans.

Changes in shutter speed affects the live image, as does changes in iso, but only up to a point where the image is slightly over exposed. After that, there is no difference in live view from say, 20 secs exposures upwards. The live view image of a 20 sec exposure is the same as a two minute one, though the actual recorded images are correct.

Is this a problem with the software, or does it protect the screen from showing a blown out out exposure, or is this even relevent when taking astro pics? What I am concerned about is that live view wont tell me if I am overexposing. This may not be a problem with deep space objects but could pose problems with the planets and moon.

Anyone had any experience with this? Does it sound like it's working as intended?

Thanks, Tim. 

[Psychobilly]

The display in live view is a "simulation" of the exposure and only really works over a limited range of lighting conditions... is the exp sim  text flashing...

From the CPN website...http://cpn.canon-europe.com/content/education/tipsandtricks/3142.do

Using Live View and Exposure Simulation

One of the greatest advantages of Live View shooting with Canon EOS DSLRs is the ability to see, on the rear LCD screen, a live histogram and an approximation of exactly what the final image will look like. When looking at the Live View image on the rear LCD screen, you may see ‘Exp.SIM’ (which stands for Exposure Simulation) shown in the bottom right hand corner of the screen. If this is shown in white, it indicates that the image you are seeing on the rear screen is close to what the final image will look like. If the ‘Exp.SIM’ is flashing it is probably because you are shooting in very bright or dark conditions, thus indicating that the image shown on screen will differ from that captured. If this is the case, you should judge your exposure from the histogram and exposure scale, rather than from looking at the LCD screen.

[StargeezerTim]

Thanks,

It works as you describe!  Problem is that I don't get the live histogram or exposure meter on APT (it will display the histogram of taken images, but not live view). When I connect APT to the camera, It turns the live view camera display off and just displays the image on the computer, minus the histogram etc etc. I can turn on the display on the camera so I have both available, but it seems quite complicated to an old geezer like me who is looking to simplify things.... 

Tim. 

[Starlight 1]

You will not see it in live view but when you hit the shoot button you see it in histograme. so  take one shot look at histograme ajust and so on.

[Yoddha]

Hi Tim,

The LiveView will not help you to determine the right exposure for astro imaging Also the exact exposure for LiveView can't be controlled precisely - you set what you want and the camera gives what it decides.

I definitely recommend the turn-off the display when you do astro because it is a source of serious thermal noise...

[Starlight 1]

edit post

[StargeezerTim]

Hi Tim,

The LiveView will not help you to determine the right exposure for astro imaging Also the exact exposure for LiveView can't be controlled precisely - you set what you want and the camera gives what it decides.

I definitely recommend the turn-off the display when you do astro because it is a source of serious thermal noise...

Thanks....   and battery loss as well...