Lens or camera problem: Been having a problem using a 500mm Sonyof or a Minolta lens. The problem I am having is that I have no autofocus with a f8 t stop setting. Manual focus the...

bnsf

Been having a problem using a 500mm Sonyof or a Minolta lens. The problem I am having is that I have no autofocus with a f8 t stop setting. Manual focus the lens works great and have good but not the best results in,the photos I have taken.

I have now purchased a Tamron 150-600 mm autofocus lens with a focus motor in the lens and a f stop of 5-6.3.,I need to know if anyone has used this Lens on a Sony Alpha a77M2 camera and how where the results of there photos.
Thanks,
Dennis

nicksr1125 Loc: Mesa, AZ

Haven't used the Sony or Minolta 500 mirror lens. However, most DSLR's (there are some exceptions) won't autofocus if the minimum f/stop is f/8 or higher. I've put a 2x TC behind my Tamron 150-600 & it won't autofocus on my Alpha 850. Without the 2X TC the 150-600 is tack sharp.

bnsf

This is what I was thinking. Called Sony talked with a design engineer and he told me that the autofocus for the a77M2 do not like high f stops of f8 or higher for autofocus. They prefer 5-6.3 or lower. That was the way the camera was designed. Wish the new Sony 500 lens at f4 would not be so expensive. Wish Sony would make one under a grand. This is why i brought the Tamron. They guarantee that it will autofocus when you are using the Sony a77M2 or a Sony a99.

nicksr1125 Loc: Mesa, AZ

It's not the fastest lens I have but, mine is all the way out at 600mm most of the time.

billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

bnsf wrote:

Been having a problem using a 500mm Sonyof or a Minolta lens. The problem I am having is that I have no autofocus with a f8 t stop setting. Manual focus the lens works great and have good but not the best results in,the photos I have taken.

I have now purchased a Tamron 150-600 mm autofocus lens with a focus motor in the lens and a f stop of 5-6.3.,I need to know if anyone has used this Lens on a Sony Alpha a77M2 camera and how where the results of there photos.
Thanks,
Dennis

I believe you are talking about the Minolta Mirror F8 lens. And,if yes, yes, I do own this lens and the A77II, and, I have no problems using this lens, however, you only have center focusing, it will not work in any other mode. And, if yours will not auto focus, then you were sold a bad one and you need to return it ASAP.

CatMarley Loc: North Carolina

bnsf wrote:

Been having a problem using a 500mm Sonyof or a Minolta lens. The problem I am having is that I have no autofocus with a f8 t stop setting. Manual focus the lens works great and have good but not the best results in,the photos I have taken.

I have now purchased a Tamron 150-600 mm autofocus lens with a focus motor in the lens and a f stop of 5-6.3.,I need to know if anyone has used this Lens on a Sony Alpha a77M2 camera and how where the results of there photos.
Thanks,
Dennis

Autofocus depends on the sensor which, depending on the camera, uses one or both of two methods of discriminating when the subject is in focus. (phase detection or contrast) Obviously this depends on the amount of light reaching the sensor. When the lens is stopped down or in low light, the sensor has not got enough information to decide on focus. Some sensors are better than others.

wj cody Loc: springfield illinois

if i were to use a lens of 500mm or greater, i would never depend on autofocus for best results. manual focusing is a must for such lenses, particularly mirror lenses.