minolta 400mm 4.5

[spudhead]

quick question minolta 400mm 4.5 high speed , with teleconverter I have minolta 1.4 and sony 1.4 which both work ok with said lens does anyone know if why the sony 2x does not give auto focus but reports focal length etc, I did think it should work and yes minolta 400 is 5 pin

 

[Uncle Kevriano]

I think AF needs f8 as a bare minimum, so there is the answer with the 2x, especially with an older lens.

 

[spudhead]

ok thinking about it I think I have read that somewhere , old age creeping up on me, just trying to thin things down a bit as I am still in e-mount and a-mount camps and love the old minolta glass on 42 mega a99ii

 

[Uncle Kevriano]

ok thinking about it I think I have read that somewhere , old age creeping up on me, just trying to thin things down a bit as I am still in e-mount and a-mount camps and love the old minolta glass on 42 mega a99ii

I was a Minolta shooter for years, fabulous cameras and lenses.

 

[garuda]

quick question minolta 400mm 4.5 high speed , with teleconverter I have minolta 1.4 and sony 1.4 which both work ok with said lens does anyone know if why the sony 2x does not give auto focus but reports focal length etc, I did think it should work and yes minolta 400 is 5 pin

I think AF needs f8 as a bare minimum, so there is the answer with the 2x, especially with an older lens.

Kev, now I'm confused and need clarification, as I'm now considering a sony 2x for my 200-600 (and other native lenses). This f/8 min. restriction is new to me.

Are we talking about the usual 2-f/ clipping when using a 2x tele? If you're referring to something different, please explain in some detail as to (possibly a7R iv) needing minimum f/8 ap (with 2x) for AF and tracking function w the Sony lenses for some other reason. For example, what about 2x tele on a 2.8 lens on Riv? Remember, you're talking to the local village idiot, so pls use small, one-syllable words while explaining.

 

[garuda]

Kev, I'm serious about not knowing about the f/8 min limitation when using 2x tele. I know about the 2 f-stops sacrifice w 2x, but is the f/8 min you mentioned applicable to all lenses compatible with 2x tele? For example, what about 2x tele on a 2.8 lens on Riv? Is there still an f/8 minimum?

I've not heard of this f/8 minimum. Am I reading the conversation on this thread wrong? And I'm curious because I'm thinking about buying the 2x tele.

 

[Uncle Kevriano]

Kev, I'm serious about not knowing about the f/8 min limitation when using 2x tele. I know about the 2 f-stops sacrifice w 2x, but is the f/8 min you mentioned applicable to all lenses compatible with 2x tele? For example, what about 2x tele on a 2.8 lens on Riv? Is there still an f/8 minimum?

I've not heard of this f/8 minimum. Am I reading the conversation on this thread wrong? And I'm curious because I'm thinking about buying the 2x tele.

I'm trying to find the info, but I recall reading that using the 2x on the 200 600 stops AF functioning as it needs to have an f8 minimum available. Obviously, with a 2.8 you are fine, because you have 5.6 available, whereas 2x @ 5.6 is 11.
I'll seek the info.

 

[garuda]

Kev, you don't have to look it up, if you read that somewhere, then it must be true. I mis-stated my concern slightly. I want to use 200-600 and 1.4, 1.8, and 2.8 lenses stopped down to f/11 or more. As you likely know from my posts, I buy 1.8s and 2.8s lens, but I still love DoF and so shoot at 11 or more in many cases. I don't always have time for AF to lockon when birds or skydivers are moving fast. So, depend somewhat on DoF, hence f/11+ when there's lots of ambient. When they're coming straight at you, they're not in frame very long with a prime (135 2.8 GM); af-lockon is challenged.

But reluctant to go $500 on 2x if ap restrictions tend to limit wide DOF. Though I guess I can brighten in post, but still not a very clean image. Thanks, but don't bother with your look up, I'll do some research or check w my Sony guru on this.

And I'm also heading for a new 70-200 2.8 GM.

P.S. -- found this for what it's worth for 2X compat:

 

[spudhead]

so I have the sony a9 and 200-600 plus 1.4 converter and it works ok in good light at f8 at 200 end and f9 at 600 end. I have the a7iii and the 1.4 teleconverter is not good on that it is slow and hunts a bit with the same lens but that seems to be well reported and I was aware of that before buying.

 

[garuda]

so I have the sony a9 and 200-600 plus 1.4 converter and it works ok in good light at f8 at 200 end and f9 at 600 end. I have the a7iii and the 1.4 teleconverter is not good on that it is slow and hunts a bit with the same lens but that seems to be well reported and I was aware of that before buying.

I'm not knowledgeable about the teleconverters. And I may totally wrong in my assumption that if you have 1.4, 1.8, or 2.8 GM lenses, that because of their superior build qualities (XA glass, dual motors, electronics. etc), that will function somewhat better in AF & tracking even at marginal thresholds --- like at beyond the customary 2-stop sacrifice for the 2x tele.

The thing that throws me is the f/8 that keeps coming up. Wondering if that threshold for 2x is a fixed number or just the coincidental f-stop for a specific lens. And when the stated minimum is f/8 (as you mention works well w your a9/200-600), I question what happens at f/11 or beyond. Does the image merely get darker, does the AF bog-down from lacking light, and/or distortions begin from the added 2x magnification glass? Also want to use 2x w 70-200 2.8 GM, as well as 200-600.

Gary, with 9/200-600 x1.4 combo, what exactly happens at f11 & f16? And what changes when zooming fr 200 to 600? In addition to image qual, how does AF and tracking-lock behave at higher (smaller ap) f-stops?

Below is a quote from f-stoppers website on 200-600 Review:

 

[spudhead]

Hi so what happens at f11 and f16 is you take pictures if the light and settings allow, thats with the 1.4 converter the only e-mount I have , to clarify with the a9 and 200-600 the f8 is what you start with on the short ie 200 end and f9 on the long end ie 600 thats , I dont think a 2x on the 200-600 would be much use, but others may know better. Also the 1.4 does not work as well on my a7iii as it does on the a9 hope this helps