Tethered camera body (no objective) + EOS Utility - the live image on the PC is much too dark...

[CesareBrizio]

Dear all,
I just bought a Canon EOS 550D body to make my first steps with a tethered photo camera (I’m quite expert with USB video cameras).

I was attracted by the possibility to use “Canon EOS Utility”. I can in fact take pictures on the PC, but there is an huge problem.

Please understand that I use the camera body without any objective, in manual mode, with an eyepiece adapter. The camera peeks into the microscope tube. So, “Canon EOS Utility” has no way to set, or know, the aperture - just ISO and exposure time.

Whichever the reason, both the full-image and the zoom preview are incredibly darker than the actual image that I capture (see attached image). In other words, the “live view” on screen does not give any useful information about the final result of the image capture.

If I set ISO and time to get a decent picture on the PC screen, the captured image image is terribly overexposed. On the other side, if I set ISO and time to get a decent picture, I can’t see it in the preview, as shown in the attached picture…

As a newbie, most probably I’m missing something…

Here comes the question: did someone use Canon Eos Utility with just the camera body and a microscope, no objective attached? Is there a way to have the live image match the look of the image captured even when the camera body is used without an objective attached??

Many thanks, excuse my bad English.

Cesare

[Waddizzle · Accepted solution]

Use Av mode, and dial in an Aperture value. 

[CesareBrizio]

Thank you, I'll try in a few hours and get back to this thread.

[CesareBrizio]

Thank you, Waddizzle! As soon as I entered the Av mode, the preview became consistent with the final result. Most probably my error was keeping the camera in M mode, as I usually do n the non-tethered scenario.