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View Full Version : canon 300mm f/4L - sharpness issue



Dr. Souvik Sardar
27-01-2013, 12:24 PM
hello every1, i'm in a state of utter confusion and tension regarding my newly bought canon 300 mm f/4L is usm lens. i jst got the lens 2weeks ago and went on a short trip to gujarat. the problem is that i'm not truly satisfied with the kind of sharpness/iq it is giving. i don't know if this is it or there is something that i'm missing :confused: would love to hear from you.m attaching few of d pics wid exif data. camera used -canon 550d

waiting for your valuable reply. thanks.

picture 1 :

shutter speed : 1/1600
iso : 400
aperture : f/6.3
evaluative metering
manual mode (m)
ai servo focussing
IS not used

Dr. Souvik Sardar
27-01-2013, 12:29 PM
picture 6

1/2500s
f/5.6
iso 400
manual mode (m)
ai servo focussing
evaluative metering
is not used

Dr. Souvik Sardar
27-01-2013, 12:31 PM
picture 7

1/2000s
f/6.3
iso 400
manual mode (m)
ai servo focussing
evaluative metering
is not used

Dr. Souvik Sardar
27-01-2013, 12:37 PM
PICTURE 9

1/1250s
f/5.6
iso 400
evaluative metering
manual mode(m)
ai servo focus
is not used

Dr. Souvik Sardar
27-01-2013, 12:42 PM
picture 8

1/800s
f/6.3
iso 400
manual mode (m)
one shot focus
evaluative metering
is not used

Sabyasachi Patra
27-01-2013, 11:09 PM
1. Have you uploaded full frame images or have your cropped them?

2. did you knowingly not use IS?

3. To remove the human variable, it would be good if you just place your lens either on a tripod, bean bag or some support. Then place a newspaper front page with headlines as well as smaller sized print on a wall. Click one image with manual focusing and another with auto focus. Better to use your inbuilt timer of 10 seconds. That will completely remove the shake. We can then see if the camera is failing to autofocus. Sorry for asking this test, as I would like to completely remove the human element and be sure that the equipment is failing to autofocus. I have used this lens for a long time and am highly satisfied with that lens. Did you buy the lens from authorised place or from grey market?

Cheers,
Sabyasachi

Dr. Souvik Sardar
28-01-2013, 12:01 AM
thnx sabysachi sir fr d rply..

1. Yes sir, i'v uploaded d full frame images... dey are'nt corppd.

2. regarding IS i thought at higher shutter speed dis fucntion wont be required nd may decrease d image quality.

3. nd i bought dis lens frm grey market @kolkata. nd dats y m really tensd... well d price i paid fr d lens might be less dan d actual market price bt still it was too high fr me.. n d kind of images i xpectd n d result i got are not goin at par.. i dnt knw wat to do wid dis.. will d service centre entertain ny grey market lens??

Dr. Souvik Sardar
28-01-2013, 12:11 AM
i'l do d test dat u'v recommended... n i'l let u knw

Sabyasachi Patra
29-01-2013, 11:01 AM
The service centre will definitely check the lens and will charge about 2.5k just to check it. However, lets first get the tests done as I suggested and then review it.

Jitendra Katre
29-01-2013, 08:00 PM
i don't think there is any problem with resolution of your lens. only image of peacock is slightly soft. a lot depends on camera settings, ( like in camera sharpning) and the image processing. try switching on IS all the time. also it may take some time to get used to your new lens.

Rajan Kanagasabai
15-02-2013, 06:18 AM
The focal point on the pelican photo seems to be on the water splash. However the gull photo is intriguing. With such a high shutter speed and a reasonable apreture, the feather tip blur is hard to fathom.

Switching on the IS, along with Sabyasachi's advice on the test sequence may isolate the issue. Are you also on a manual White Balance ?

Lastly, at the risk of being rude, would be nice if we stay away from the SMS language on posts.

regards
Rajan