Problems with 300mm f4 IS

squizza

squizza

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Hi guys

Please someone reassure me that I'm not the only one with problems with getting sharp images from my 300mm. I usually have the 1.4x on, but even without the converter on I'm struggling to get sharp images. I'm making sure that my shutter speed is up.

Even when balanced / rested on a bean bag at the bird hides I often go to, the images aren't sharp. I try to avoid wide open when possible.

Or is it just because its a lens to be mastered?

Any help or advice greatly appreciated.

Kind regards

sarah
 
Could you post a sample? Have you tried photographing a test chart straight-on like in the 7D micro adjustment thread?
 
Are you able to post some examples with the EXIF info?

I seem to remember you posting some shots of owls/birds of prey which were pretty spot on, weren't they :shrug:
 
I suspect user error TBH ;)

If you're shooting birds at maybe 5m distance to get a decent close up even with 300mm plus 1.4x TC, DoF at f/5.6 is only 2.8cm deep. That's barely more than an inch and it is so easy to be that much out. Focus on the body instead of the beak, and you're out; bird moves and you're out; you move just little after focusing and it's out again.

Add all these factors together and you really have to be on it to get consistently sharp images. I always use centre point AF and am constantly focusing and refocusing all the time. I will compromise composition (crop in post) in order to nail that AF square on the bird's eyes, or use an off centre AF point if necessary. I think most birders generally use centre point AF.

It's easy enough to check AF accuracy with your live view. There have been a few threads on it lately. On a tripod, AF on a good clear target at a typical shooting distance (not too close). Switch to manual focus in live view and max mangification, and see if you can improve on it. Do this a few times. Live view AF in this way is very accurate indeed.
 
The problem isnt visible with the medium sized images allowed to post here. I don't know how else to show what I mean. I have a picture, but would have to put a picture bigger than the allowance? The softness shows when at A4, and this is with the picture sharpened.

What to do?
 
pearce_jj said:
Could you post a sample? Have you tried photographing a test chart straight-on like in the 7D micro adjustment thread?
Click to expand...

I havent - the problem being that my manfrotto head isn't strong enough to hold the camera body and lens without it creeping which would in turn, void the test?
 
NOTE TO MODS:

Would I be able to post an image bigger than the allowance for the purpose of this thread only? Once I have had help and advice I would delete the image?
 
post up a 100% crop of part of the image.
 
My 300mm f4.0L/IS is tack sharp even with a 2x & a 1.4X on it, on its own it is the sharpest lens I have to hand in my collection. Without seeing an image it is hard to say really but to be sure you may want to run it down to Canon and have then sync it up to your 50D

Make sure you have the IS OFF or set to 1 and try again
 
4005030363_08204c254e.jpg


When zoomed in on the head, its soft. But that was my focus point :thinking:

Different one, cropped in.

4005075833_0401df5889.jpg
 
The top one
Camera: Canon EOS 50D
Exposure: 0.001 sec (1/1250)
Aperture: f/4.0
Focal Length: 300 mm
Exposure: 0.00
ISO Speed: 500
Exposure Bias: 0 EV
Flash: Off, Did not fire

The secondCamera: Canon EOS 50D
Exposure: 0.001 sec (1/1000)
Aperture: f/4.0
Focal Length: 300 mm
Exposure: 0.00
ISO Speed: 500
Exposure Bias: 0 EV
Flash: Off, Did not fire
 
squizza said:
4005030363_08204c254e.jpg


When zoomed in on the head, its soft. But that was my focus point :thinking:

Different one, cropped in.

4005075833_0401df5889.jpg
Click to expand...

Not sure if the 50D has this capability, but on the 1D, you can view the focus point in the histogram page by switching them on in the camera menu, other wise use zoom browser, I think you can see the focus point by using that software.
 
Playback 2 menu

Highlight alert (on/off) - shows clipped highlights
AF point display (on/off) - shows the AF points that were used
Histogram (Brightness, RGB)
Slideshow
Image jump with main dial (1, 10, 100 images, screen, date, folder) - how many images are skipped when using the main dial

you should be able to turn on the focus points used in your camera menu, then when you view the image as info, histogram etc, you should see where your focus point was.
 
Cheers, not camera shake then ;)

1st one is backlit so you will not get much definition around the eye, or on this side of the birds neck, the edge of its bill looks well defined where the light is hitting it.

2nd one again I think is down to lighting, or lack off in this case, this one looks to have a more diffused lighting, which again you are not getting a lot of definition to edges, the best I can see in such a small image the water drops below its chin appear sharp and well defined.

It is a job to tell on such small image sizes, best bet would be to test it on something more controlled, try photographing a cereal packet and see how the type holds up. Just set it up the other side of the room and the flash to even out the lighting. Zoom in if the text is clear and defined all is well.
 
pete.rush said:
Playback 2 menu

Highlight alert (on/off) - shows clipped highlights
AF point display (on/off) - shows the AF points that were used
Histogram (Brightness, RGB)
Slideshow
Image jump with main dial (1, 10, 100 images, screen, date, folder) - how many images are skipped when using the main dial

you should be able to turn on the focus points used in your camera menu, then when you view the image as info, histogram etc, you should see where your focus point was.
Click to expand...

Okay will do this... give me a sec and I'll reply with the result.

Martyn... said:
Cheers, not camera shake then ;)

1st one is backlit so you will not get much definition around the eye, or on this side of the birds neck, the edge of its bill looks well defined where the light is hitting it.

2nd one again I think is down to lighting, or lack off in this case, this one looks to have a more diffused lighting, which again you are not getting a lot of definition to edges, the best I can see in such a small image the water drops below its chin appear sharp and well defined.

It is a job to tell on such small image sizes, best bet would be to test it on something more controlled, try photographing a cereal packet and see how the type holds up. Just set it up the other side of the room and the flash to even out the lighting. Zoom in if the text is clear and defined all is well.
Click to expand...

I was hoping it was user-lack-of-technical-ability :lol:
 
Sarah

I bought one of these from Kerso about 4 weeks ago for my low flying aircraft.
I use it on my 50D and compared to my 100 - 400mm its in a different league all together.
I know there's a lot more focusing area on an aircraft than a bird but I'm well pleased with mine.
The only thing I would alter on your settings with regard to the swan photos is decrease your shutter speed slightly and close the lens aperture down to compensate.
Must admit I've never used mine down as low as f4 yet - don't know if these lenses are slightly soft fully open or not :thinking:. I'm sure someone will soon tell us ;).

Cheers Paul.
 
User-error (thankfully) seems more like the problem. The first shot the focus point is bang on the eye area - which is black, which i suppose is why it couldnt pick it up properly?

Second one, was on the beak. . . .. . I'll get my coat. lol :lol::bonk:

Am about to try a test with the cereal box
 
paulh said:
Thanks to Pete Rush I've learned something as well - about viewing the auto focus points :amstupid:

Thanks Pete :thumbs:
Click to expand...

I didn't have it on my 20D, but it's something that has come in very hand on the 1D for motorsport and aviation, I can't live without it and helps to home technique when only using one focus point and trying to keep it focus on the subject, I've also so focus point expansion switch on was well, but not sure the 50D has this capability, I've got 50 odd focus points to play with on the 1D :D
 
Ok guys - its defintely me - just took a picture of the gda guidelines on a box of Rice Krispies (other brands are available)...I would post it but its absolutely fine, plus I really can't be bothered. lol

Photographed from a distance, and zoomed in - pin sharp.

As I said...I'll get my coat :lol::exit:

Thanks for all the advice guys ! :thumbs:
 
Sarah, 300mm lenses do not have much depth of focus, especially wide open at f4, this will effect the perceived sharpness of subjects, sometimes you do not have much room for error.

It should be sharp wide open at f4.
 
squizza said:
Ok guys - its defintely me - just took a picture of the gda guidelines on a box of Rice Krispies (other brands are available)...I would post it but its absolutely fine, plus I really can't be bothered. lol

Photographed from a distance, and zoomed in - pin sharp.

As I said...I'll get my coat :lol::exit:

Thanks for all the advice guys ! :thumbs:
Click to expand...

Result :thumbs:
 
also there's some noise evident in the samples posted, which reduces the apparent sharpness.
 
pearce_jj said:
also there's some noise evident in the samples posted, which reduces the apparent sharpness.
Click to expand...

Thank you:thumbs:

Thing is....I should/do know all the advice given. Please don't see this as me being ungrateful - I am grateful for all help - its just amazing that when I'm out photographing all the knowledge seems to go out the window, and I end up with soft shots.

Must-think-before-shooting :lol:
 
squizza said:
Thank you:thumbs:

Thing is....I should/do know all the advice given. Please don't see this as me being ungrateful - I am grateful for all help - its just amazing that when I'm out photographing all the knowledge seems to go out the window, and I end up with soft shots.

Must-think-before-shooting :lol:
Click to expand...

you an me both ;)
 
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