focus (1 Viewer)

I've just started using a canon 75-300 usm on my canon 10D my photo out too 65 or 75 yards are sharp and in focus but farther out they seem soft and outof focus I'm using a good tri pod do.I need to use a higher f/stop or ?
Thank you

I don't know if you're shooting mostly at the widest aperture or not...but generally you will get sharper photos at higher f-stops. I used to own the 75-300mm and found it to be quite soft, especially at wide apertures and 300mm. Make sure you are using the fastest shutter speed possible, as well, even if you are using a tripod. All that being said....I just couldn't get the results I was hoping for, and have since traded that lens (and a goodly sum of cash) for a 100-400mm lens and am now getting some very sharp photos at all distances. The glass makes a HUGE difference. But don't let me give you the false impression that the 75-300 lens won't perform quite adequately under good light, moderate apertures, and higher shutter speeds. Keep experimenting!
Muskrat

Sounds like a faulty lens - "soft" is a trul comparative term, I should hope, when used for this lens. Canon lenses are "sharp" by any standards but this zoom would lack the absolute punch of a fixed telephoto lens. However, you should not be left wondering, at all, about the focus.

Take it back to the supplier and ask their opinion.

Thanks for the help
( Tom

One other test to do, given that the 10D has a slightly cruel reputation of poor focusing on occassion, is to take a shot of a subject that is inclined at the distance - typically the grass on the ground. Then, view the image on a hi-res monitor and see if the "best" focus is at the distance of the focal point or either in-front or behind that point.

If either of those is the case, then you have a 10D adjustment to have made. I do not know what Canon's attitude / warranty / charging is in your location; I have the service manuals / software for my D30 and D60 which allows this adjustment - but I had these imported from the US as Canon Europe has a very poor attitude to consumers and after sales service. OTOH Canon UK are great - just tied by EU policies...