The focusing ring is hard to turn on my 28-200 quantaray lense for my nikon camera

SOURCE: auto focusing problem

The D40 will only autofocus with the Nikkor AF-S lens...look for the AF-S in the lens title. For 3rd party lens, only SIGMA with the USM title will autofocus.

To use the T-adaptor...you will need to use the "Manual" mode of the camera.

Sachin Gharat

• 28 Answers
• Posted on Jul 12, 2009

SOURCE: quantaray 18-200 auto focus quit working

HI I AM SAGHA I THINK YOUR LENS MIGHT HAVE A PROBLEM WITH MAGNETIC AUTOFOCUSING SENSOR UNIT.BETTER GET THE SENSOR REPLACED WITH THE ORIGINAL ONE.AND UR LENS WILL BE OK.TRY THIS FROM PROPER SERVICE PERSON DON'T TRY YOURSELF

SOURCE: Quantaray lenses

I bet they are not AF lenses. There are adapters that add the AF contacts to "fool" the camera but increase the zoom. You can get used lenses from many "on line" camera stores with warranties for a few months.

SOURCE: I have a quantaray 70-300mm

The D40 body can only autofocus if the lens is equipped with it's own in-built autofocus motor. If you have an AF lens which relies on the camera body having the AF drive motor then you have to use MF only. To cut cost and weight, the D40 relies on using lenses with their own AF motors.

Quantaray is a Ritz badge-engineered product, usually based on a Sigma/Tamron design but not always identical to those brands internally. As Ritz don't have a UK/European presence they're unfamiliar to me, but if it's the same as the one shown on this website, then it definitely lacks a drive motor, the second photo down when enlarged clearly shows the mechanically operated AF coupling at the six o'clock position. Again, to cut cost, the lens shown does not have a built in AF drive motor.

If so, your only fix is to either upgrade your body or lens to versions which aren't cut price models, or to simply focus the good old fashioned way, knowing that what you've focused on is what you want and not what the camera thinks you want... ;-)

SOURCE: Quantaray lense wont work on nikon D50

David -

The lowest setting is the highest number; f22 is lower than f4. It's little counter-intuitive, but the lowest setting means the least amount of light - or the smallest aperture opening - not the numerical "f" value of the opening.

Simply twist the aperture ring until the highest value "f" number is selected. Many lenses have a small tab or latch to lock them in this position - if yours does, you can use it to prevent this from happening again. You would use a command dial on most camera bodies to electronically change the aperture opening.

Good luck!