George, you are right, shooting like that can be tricky. The problem is that one shot is fine, and the next, taken a second later on the same pass, is drastically overexposed as Mike puts it, so that even a little tinkering in Photoshop can't save it. And that with the camera set to underexpose.

If the lens/camera combination is consistent in its exposure then that is fine, and I can adjust accordingly if it is a little off. But to have good exposure in one shot, and then have drastic overexposure a second later, and then go back to good exposure a couple of seconds later ... well I can't adjust for that and I can't explain it. Hopefully someone else can.

I'll see if I can post a couple of examples, with exif information from both. I just need to retrieve the overexposed shots from the recyle bin

Thanks

Hi,

New to the forums and not sure if this problem has come up in the past or not. Soory if it has already been discussed.

I have a Tamron Adaptall-2 60-300 mm zoom with a P/KA mount. Bought years ago in the days of film and still a great lens. I am now using it with a K100D, but I am not entirely happy with the results.

I use the lens most often for airshows, since I have a new Pentax 50-200 for routine zoom use. With the Tamron, I am having problems with getting consistent exposure. I always need to underexpose by 0.5 or 1.0 stops. When it works, it works great. But on a single pass of an aircraft, I might get a couple of shots that are well exposed, mixed with shots that are overexposed. It seems like the camera is searching for the right exposure. I am usually shooting in Tv mode at 1/250 to keep a reasonable amount of prop blur on prop driven aircraft, with higher speed for jets.

It is frustrating to come home at the end of the day and have to delete so many othewise great shots. Any advice? Is there something I am doing wrong? Could it be related to the contact problems with the P/KA adaptor that I have read about on other sites?

Thanks