Changing aperature doesn't change meter readings on Canon t90

[kurt_driver]

<p>When I change the aperature on any of my lenses the meter reading in the viewfinder doesn't change. This is wether it is stopped down or not. Kurt</p>

[User_4136860]

<p>Have you got the lenses set on "A" ?</p>

[Giovanni Cappai]

<p>If the camera is not in stopped down mode then correctly the meter reading doesn't change when you change the aperture value on the lens. The reading on the viewfinder is the camera suggestion but since you are in Manual mode you choose the aperture (this is one of T90 problems: it doesn’t have any sort of "match needle" metering).<br /> If it doesn't change in stopped down mode then you have a problem. Does the aperture close when you turn the ring?</p>

[kurt_driver]

<p>Thanks guys, I don't understand how it could be on "A" when I'm turning the aperature ring. Something else I don't understand, I just got this Canon 28mm F2.8 lens a couple weeks ago. I took some good pictures with it, this for instance, http://profile.imageshack.us/user/kurtdriver/images/detail/#197/img00001u.jpg so I'm not sure what happens in the finder. if I set the shutter speed according to the meter at F22 and then turn the ring to F2.8 the reading does not alter. When I look at the back of that lens, I can't see the blades, nor can I on a tokina FD zoom. But there they are on the 50mm 1.8. So, I don't know if the aperature changes (it must or the pics would not be exposed correctly) on the 28mm. If I turn the ring on the 50mm the blades do not appear to open or close, again this lens on that camera have made some nice pictures. It would appear that I need to learn a thing or two about lenses because my Mamiya RB67 180mm lens doesn't show me it's blades either. So I just set the eoseure on a white wall in this room at F22 and in stopped down mode the match needle reads correct at 1/8 second. I then exposed for a dark room through a door, after which I set the aperature to F1.8 (on the 50mm) and it still reads correct at 1/8. This is what I do not understand. That and the lack of visible blades in those lenses. Giovanni, you're sure right about the lack of match needle metering, I got used to it in my AE-1 and always shoot the T90 in stopped down mode. It's a powerful camera, I ought to explore it a little.</p>

[tomscott]

<p>All FD lenses stop down at the time the shutter is depressed. In other words they meter "wide open" regardless of whether the aperture ring is on A or not, as far as being in stop down mode, with my F1 and EF if you hold the DOF lever over in stop down position you can watch the aperture blades open and close as you turn the ring. The meter does change when you stop down manually. I don't own a T90, only T model I have is the T70 and it doesn't have a stop down mode or DOF preview. Hope that helps.</p>

[Member69643]

<p>The T90 doesn't know what aperture you are using if the lens is not set to A and meters at wide-open. I have my T90 in the car and will check the stop-down functionality here in a couple minutes, but I believe it should move the meter if the lens is manually stopped down.</p>

[icog]

<p>Hey Kurt,</p>

<p>Put the camera in AV mode, set the lens to A and then change apreture with the thumb wheel. That will change the shutter value in the viewfinder. Otherwise you'll have to meter in the stopped down mode using the lens ring and the slide lever on the front of the body.<br>

Hope this helps,<br>

Lionel</p>

[awahlster]

<p>Have you read the manual?</p>

<p>if not WHY??? it can be found here for free down load.</p>

<p><a href="http://rapidshare.com/files/214835807/CanonT90.pdf">http://rapidshare.com/files/214835807/CanonT90.pdf</a></p>

[kurt_driver]

<p>Thank you Mark, I have read it, page 79 seems to cover this subject and suggests that it should behave differently from the way it has been.<br>

"Turn the aperature ring until the 'oo' is displayed". When I changed the aperature, no change appeared in the finder, which is why I asked the question. Incidently, Mike Butkus works hard to put up orphaned manuals and deserves a lot of support. Also I won't download software from unknown sources, which is that PDF is.<br>

http://www.butkus.org/chinon/</p>

[philip_wilson]

<p>I check both of my T90s and they function the same way. When the lesn is off A and the camera is not stopped down then you just get the meter reading based on how the camera is set up. Your question appears to relate to stopped down use. In this case you will see the side display showing the horizontal bar indicating where your exposure is relative to the metered reading as you turn the lens aperture. The center point is when the exposure matches the meter at which point the display will show oo</p>

[kurt_driver]

<p>Thank you Phillip.</p>