Sweet Spot for Canon 75-300mm F/4-F/5.6 III

[Stefan Minnig]

While still learning much about birds and photography, I was wondering what would be the best aperture for shooting birds with a Canon 75-300mm F/4-F/5.6 III lens. I realize that I am not going to reproduce bird images with the clarity of an "L" series lens, but I would like to have this one perform at its best despite its limitations. I've heard that from F/8 to F/11 is good, but I cannot remember where that info came from.

[Alfred Forns]

Stefan your lens will perform better at f 8.0 than wide open at 5.6. If you have enough light for adequate shutter speed and dof will not be a problem would be fine. Otherwise do not hesitate making the image wide open.

Best thing to do is see for yourself and make images at test targets with different apertures, the little difference will surprise you.

[John Chardine]

Stefan your lens will perform better at f 8.0 than wide open at 5.6. If you have enough light for adequate shutter speed and dof will not be a problem would be fine. Otherwise do not hesitate making the image wide open.

Best thing to do is see for yourself and make images at test targets with different apertures, the little difference will surprise you.

Stefan- Agree with Alfred. Testing in-house is fun and instructive. Set everything up so that it can't move, use mirror lockup, cable release, self timer, flash- whatever you can do to eliminate variables other than F-stop. Pick a nice flat target with lots of detail- a bank note works well, and shoot in one stop increments from open to closed. Examine at 100% in Photoshop and you should see the difference.

[Stefan Minnig]

Thank you both for the tips. I'll do some testing and see what I can find out. I know already that if I'm shooting wide open at maximum zoom, the bird's head will be in focus, but the tail will not be. That is if I'm shooting a frontal pose. I've never used the mirror lockup feature for shooting, so I'm in for a real treat. I'm sure the manual will have some helpful information on that.

[Alfred Forns]

Stefan Might want to check out a depth of field chart.

With the example you are citing, bird frontal pose, at close range stopping down to the max will not get you the tail in focus. Dof for a 300 lens at f22.0 six feet away will be less than half an inch.

[Stefan Minnig]

Alfred,

Thank you. I'll maybe do a search for a DOF chart on the internet...unless you already know of a place to find one? :)

[Ed Grella]

I shoot crisp shots to 280mm as long as i shoot near f8.

[Stefan Minnig]

Ed,

Thank you for the information. I've been hoping to do some testing on the lens...that is if I ever quit surfing BPN night and day. I will give what you said a try.

Maybe one day I can graduate to a nice "L" series lens...Dreams, Dreams, Dreams.

Thanks,

Stefan