Canon Rebel XT

[vanewb]

I was just given a Canon Rebel XT and it came with an ultrasonic 75-300mm zoom lens. I've been using it to photograph surfers. It works fine, but once I get to 300, the pictures start to get blurry. Is this lens just not that great of quality? Or are there any other zoom lenses you guys would recommend? I just started doing this so I'm not really sure what to get

 

[o hey tyler]

I was just given a Canon Rebel XT and it came with an ultrasonic 75-300mm zoom lens. I've been using it to photograph surfers. It works fine, but once I get to 300, the pictures start to get blurry. Is this lens just not that great of quality? Or are there any other zoom lenses you guys would recommend? I just started doing this so I'm not really sure what to get

Can you post a photo so we can see what degree and type of blur you're talking about?

 

[Derrel]

With most 70-300 or 75-300mm zoom lenses, the maximum amount of light allowed in by the lens at 300mm zoom setting is called "f/5.6". That is a mid-sized aperture...kind of trending down toward the "small-sized" aperture settings of f/8 and f/11....the series of f2.8, then f4, then f/5.6, then f/8, then f/11 encompasses five different f/stop "sizes"...

At f/5.6, not a whole lot of light is allowed in...and THEREFORE THE SHUTTER SPEED needed is moderately slow in anything except bright lighting conditions. Also...the depth of field is shallow, so only the focused distance, and a few feet on either side, is really absolutely critically sharp; if the focus is not spot-on on a surfer, the pictures shot at 300mm zoom will look "fuzzy". The images made at 300mm are magnified quite a bit....so any errors in focusing are VERY easy to see. 300mm focal length requires spot-on focusing for the best images. And the shutter speeds on moving objects need to be adequately "fast", like say 1/250, to 1/500 second, much of the time. The closer the subject is to the camera, the faster the speed needs to be, and the more-critical perfect focus is.

 

[vanewb]

Can you post a photo so we can see what degree and type of blur you're talking about?

Here are a couple that I used at 300mm

 

[vanewb]

With most 70-300 or 75-300mm zoom lenses, the maximum amount of light allowed in by the lens at 300mm zoom setting is called "f/5.6". That is a mid-sized aperture...kind of trending down toward the "small-sized" aperture settings of f/8 and f/11....the series of f2.8, then f4, then f/5.6, then f/8, then f/11 encompasses five different f/stop "sizes"...

At f/5.6, not a whole lot of light is allowed in...and THEREFORE THE SHUTTER SPEED needed is moderately slow in anything except bright lighting conditions. Also...the depth of field is shallow, so only the focused distance, and a few feet on either side, is really absolutely critically sharp; if the focus is not spot-on on a surfer, the pictures shot at 300mm zoom will look "fuzzy". The images made at 300mm are magnified quite a bit....so any errors in focusing are VERY easy to see. 300mm focal length requires spot-on focusing for the best images. And the shutter speeds on moving objects need to be adequately "fast", like say 1/250, to 1/500 second, much of the time. The closer the subject is to the camera, the faster the speed needs to be, and the more-critical perfect focus is.

Thank you! I'm new to this, but I get what you're saying. I took a film class in high school a couple years back. Are you saying that if I got a lens that allowed more light in, the shutter speed would be faster. Therefore making the image more clear?