Need help, A99 over-exposures vs viewfinder image

Fellow Dyxumers,

I need some help to find the correct settings for my A99 body. As you might know I'm shooting a lot of panning shots. Sometimes there is a lot of light and I need to stop down to enable the correct long exposure times of 1/30sec in combination with low ISO values of 100 or 50.

Yesterday I was at the bike park in Winterberg with a lot of sun and I noticed again that my pictures are completely washed out while my viewfinder indicates correct exposure. I had to compensate with 5 stops of exposure to get the resulting picture right but then my viewfinder turned almost black and it was like I'm hunting ghosts during panning.

I would like to understand if this is a viewfinder quirck or if there are possible settings to correct this. Hopefully other panning guys who use the A99 body can help me out.

To show this effect I shot the below pics with my mobile from the live view. As it was an overcast day I mimiced the light conditions by setting ISO to 1600. The first pic shows the viewfinder indication and as visible it shows a perfect exposre with 1/30sec and F10. The second picture shows the result which is clearly overexposed by at least 1 stop. Although not as severe as the results with even brighter weather it shows the issue I'm trying to tackle.

1) Viewfinder image before taking the shot.


2) Playback of actual shot on viewfinder.

Phil, unfortunattely your spot on. Just checked my aperture and it is slow. Not an issue on a 50mm as I cleaned lots of them but my 80-200 is quite complex on that. Will give it a shot though.

Sorry it's the 80-200, a far more complicated fix than a prime. I assume everything is working correctly with other lenses? Best to double check before taking the srewdriver to the lens.

@SnowFella, thanks for the link but I have the original CD from Pete Ganzel, although no CD-tray anymore in my laptops . Luckily it's all on my hard-drive already.

Torn her down yesterday evening and replaced the whole back-group including diafragm with the one from my old 80-200 which was to beat-up to safe. Now I'm building her up again. Of course I damaged the brittle flex so I will need to do some soldering to replace the flex neck with wires. Already had to do the similar exercise on my 17-35G (with success).

If interested I can take some more detailed pictures of the tear down as it is not always very obvious from the repair manual how things are assembled together and what you should loosen or not.

Maybe I should start my own Tinkering page

paso144 wrote: @SnowFella, thanks for the link but I have the original CD from Pete Ganzel, although no CD-tray anymore in my laptops . Luckily it's all on my hard-drive already. Torn her down yesterday evening and replaced the whole back-group including diafragm with the one from my old 80-200 which was to beat-up to safe. Now I'm building her up again. Of course I damaged the brittle flex so I will need to do some soldering to replace the flex neck with wires. Already had to do the similar exercise on my 17-35G (with success). If interested I can take some more detailed pictures of the tear down as it is not always very obvious from the repair manual how things are assembled together and what you should loosen or not. Maybe I should start my own Tinkering page

I did try to get the CD (I can still read them) but I was too late, Pete was no longer with us. As I recall there are manuals on the CD that are not available online (I was probably looking for a 35-200xi repair manual).

Any strip down/build up photos would be a valuable resource. As the lenses get older they are more likely to need to be home-serviced.