Quantaray 70-300 f4.5-5.6

[Racer23]

I have a question about this lens with the Digital Rebel. The camera will go as low as 5.6 but the lens goes lower. Does this mean I can only shoot with the 5.6 setting?

[Clark]

The camera will go to lower f stops. The lens will go to 4.5, but only at the widest zoom.
At 300 it will only open up to 5.6

[Racer23]

The lowest I have been able to set it to is 4.5. Setting it at something larger than 5.6 will over expose the picture?

[Dante King]

No, these are minimum AV numbers. At 70mm lowest AV allowed will be 4.5, at 300mm its 5.6. You can go higher to f/22 or what ever the lens allows. Exposure is a combo of AV and TV so its up to this combo to determine exposure on the image. On this lens you probably want to be shooting at a higher f-number to get the pic as sharp as possible.

[cheme]

The lowest I have been able to set it to is 4.5. Setting it at something larger than 5.6 will over expose the picture?

The camera aperture value is dependent on the lens attached to the body. So you can only set it to 4.5 because of the lens that you're using.

I think that if all things are equal, setting the aperture to a larger (numerical) value, will actually make the it close down and will probably underexposure the picture if all other settings (shutter speed, iso, exposure comp., etc) are held the same.

[lostdoggy]

The lowest I have been able to set it to is 4.5. Setting it at something larger than 5.6 will over expose the picture?

I think you need a major lesson of photography terminology. Over expose is when then the image is washed in white, under exposed is when the image is dark.

The numbers 4.5 and 5.6 are aperature values (Av) and usually quoted as f/4.5, eg. In your case, the largest opening that the lens is capable of at the widest focal length (70mm) and f/5.6 is largest opening at 300mm.

The exposure is a combination of Shutter Speed (Tv) and Aperature Value (Av), so it is not posible to over expose a photo with only one value, (Av). So I must assume you have set your camera to Manual Exposure Mode, M, and your Shutter speed is way too slow for the available light.

Simple solution.

If you want to play with Av then set the camera to the Av mode. If the LED light in the viewfinder starts to blink then you've have reach high limit of the camera and you have to stop down the Av, raise the number. If the Shutter speed gets too low say 1/250 at 300mm then you going to have to open up the Av, lower the number.

[bolantej]

try this website. click on the virtual camera. basic teachings.
http://www.camerasinteractive.com/index.php#

[Racer23]

Thank you.