Canon Digital Rebel question

With my camera on M (manual) and lens on manual, F1.8 50mm normal lens on the camera, setting B (bulb), or 30 seconds the aperture defaults to F 2.8
icon9.gif
instead of the lowest possible F 1.8.

I know the lens works ...... if I set it to Av and crank the knob it will read 1.8 in the viewfinder and on the back LCD screen with any speed. Anyone have this problem, or am I overlooking something simple? For night shooting I would obviously like to get that last bit of F-stop out of the camera down to F 1.8.

Thanks,
Gene Moore
 
Gene, have you tried setting the camera to manual, but increasing your shutter speed to see if the camera will allow you to manually open up the aperature (1.8)? In other words, keep it on "manual" setting, but set the shutter speed for 5 seconds, or something in that range. Then try to open up the lens to it's maximum aperature of 1.8. Another thing you might try, check to ensure that digital noise reduction is set to "automatic," as slower shutter speeds will often default the camera to a higher f-stop. And finally, what ISO are you using? The camera will also default to less light with faster ISO speeds.
 
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With my camera on M (manual) and lens on manual, F1.8 50mm normal lens on the camera, setting B (bulb), or 30 seconds the aperture defaults to F 2.8
icon9.gif
instead of the lowest possible F 1.8.

I know the lens works ...... if I set it to Av and crank the knob it will read 1.8 in the viewfinder and on the back LCD screen with any speed. Anyone have this problem, or am I overlooking something simple? For night shooting I would obviously like to get that last bit of F-stop out of the camera down to F 1.8.

Thanks,
Gene Moore

I have the same lens and camera and have never seen that.
 
The posts got me thinking how things work and I was able to figure out what I was doing wrong....it was nothing more than a dumb-attack on my part.

In manual mode I have been using lenses (for night sky shots) with an aperture ring* and the Canon 50mm doesn't have one. Soooo, one must use the Av button in addition to spinning the little knob up by the shutter button......it was that simple,
icon11.gif
but it wasn't coming to me last night while fumbling around in the dark.

Thanks!!
Gene

*For Astrophotography I converted one of my old FD lenses ....an 80-200 F 2.8 Tamron LD zoom. It has good glass in it and I didn't want to sell it for peanuts just because it was the outdated FD model. Using a "Hong Kong" adaptor and doing some grinding/ drilling I got it to work in manual mode. I don't need auto-anything for astrophotography, so it works fine for that purpose.
 
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