[Sumit Floyd Chaterji]

I seem to keep running into and coming here with strange situations... here's the latest one !

Just got the Vivitar (Cosina) 28-210 mm 3.5-5.6 (Non AF & Non Series 1) off ebay at a throwaway ( well ..almost) price.
Haven't taken it out for any serious trials just yet ... it's just sitting right beside me mounted on the K5II...and I've only taken afew shots out of my window - today being overcast - is perhaps hard to tell how good or not it is. I reckon this Vivitar is made by Cosina as the serial number starts with 09....

The strange thing I noticed right away about this lens is that it gives me a reading of 2.4 right uptill the 210mm FL !!! It's supposed to be 3.5.-5.6 !!
Anyone have any opinions on why it could be so ??

[k0og]

Sumit,

Congratulations on the new "superzoom" lens. That could be a convenient one-lens solution.

I presume that it is an "A" (automatic aperture) lens. If so, make sure it is in the "A" position, and perhaps rotate the aperture ring several times from one extreme to the other, then lock it back in the "A" position. If it is not in the "A" position or if it is not an "A" lens, you should not see any aperture indication in the camera and something else is wrong.

Most importantly, if it is an "A" lens, make sure that the contacts on the base of the lens AND the mount on the camera are clean. Use a clean cotton lint-free cloth (e.g., a clean cotton handkerchief) to gently wipe both clean, then re-mount the lens to see if it works properly.

When you mount and dismount the lens, I suggest that you do so with the camera turned off.

Best wishes - I hope you get it working.

-Joe-

[Sumit Floyd Chaterji]

Sumit,

Congratulations on the new "superzoom" lens. That could be a convenient one-lens solution.

I presume that it is an "A" (automatic aperture) lens. If so, make sure it is in the "A" position, and perhaps rotate the aperture ring several times from one extreme to the other, then lock it back in the "A" position. If it is not in the "A" position or if it is not an "A" lens, you should not see any aperture indication in the camera and something else is wrong.

Most importantly, if it is an "A" lens, make sure that the contacts on the base of the lens AND the mount on the camera are clean. Use a clean cotton lint-free cloth (e.g., a clean cotton handkerchief) to gently wipe both clean, then re-mount the lens to see if it works properly.

When you mount and dismount the lens, I suggest that you do so with the camera turned off.

Best wishes - I hope you get it working.

-Joe-

Thanks for coming in Joe, ... yes, it is an 'A' lens and it has been mounted on the 'A' setting as well, - the lens seems to be working all fine and I even took it out for a brief while for a check after my initial post as the sun was out of the clouds again.. and I seem to like its colors and sharpness is pretty acceptable too - so It's a working lens in every way - just that although its largest aperture is 3.5 and should be 5.6 at the longest FL, I can wheel down a reading on my camera till 2.4 !!!! - right from 28mm till zoomed out at 210mm FL !!!
I'm a bit flummoxed - there seems to be something wrong somewhere ! (The smallest aperture is 22 and thankfuly my camera doesn't give a reading beyond that !! )
With my other zooms I am getting the correct designated apertures when on 'A' - with the exception on the Pentax - A (non smc) 28-80mm 3.5, - my k5II gives me the largest aperture reading on this lens of 4.0..

But I'm quite surprised with the reading I'm getting on the Vivitar - would love to know why.