It is a Mystery to me!

GemGem

Hi everyone!

I have a D90, once in a while, the following happens to me.
I shoot mostly on A mode (aperture priority), but around the house, I use P mode (program mode, preset but with a bit of control). Everything is ok while I use P, then, when I switch the camera back to A mode to get it ready for my work it goes crazy! This happens with my Tamron 28-75 2.8 ( can't recall if this has happened with my 50. 1.8) at 2.8, pics are ok, bit soft but sharp where I focus.. at 4.5 or above the pics are totally blown up.. highlights up the hizzy, and forget it if I put it higher! I check the ISO bring it down to 200, still same thing unless I bring the f/stop down to 2.8 or 3.3. :dunno I shutter speed is about 100, but really makes no difference here since the pics are way blown out.. can't barely see anything..

Last time this happened, I ended up using the portrait and sport present, which by the way worked very nicely :ivar so I was able to get good pics.. but I like the ligthing better when I use Aperture Priority..

Can someone shed some light into this for me.... well, not too much cuz I already have enough!! :rofl

Thanks!
GG

pyry

Can you check to see if the aperture blades in the lens move?

Set the camera on manual, something like f/10 and 2 seconds, look into the lens and press the shutter release - you should see the aperture stopping down and then opening up again.

It sounds to me like the aperture is stuck open, which would require you to send it in for a service.

NateW

pyry wrote:

...It sounds to me like the aperture is stuck open, which would require you to send it in for a service.

Did you try using the DoF preview button? (let's you look through the finder for a direct comparison...)