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View Full Version : do you think i need to take my lens in for calibration?


fusiondreams
15th of December 2010 (Wed), 00:29
i dont know if its just me and shooting but it seems like my lens is either not sharp or has some focusing issues. if my pictures seem fine, any advice would be great :) ive seen other peoples photos with the lens and it seems much sharper than mines.

im currently using a canon 5D with 24-70 L 2.8 lens

east village (day) shot iso 50 f/4 70mm at 1/500 sec

times square shot (night) shot iso 800 24mm f/2.8 1/250 sec

to download photos:
http://www.mediafire.com/?xthda40b524u382

thank you in advance!

philwillmedia
15th of December 2010 (Wed), 00:58
Post your images here for us to see.
Don't expect people to click on links to see your photos if you want help.
I did, and got just some screen coming up that said blah blah blah - way too hard.
You want help, do the work to help us help you.

fusiondreams
15th of December 2010 (Wed), 00:59
i have no personal website to upload 8mb photos :( do you know of any?

Snydremark
15th of December 2010 (Wed), 01:13
Make a free Flickr (http://www.flickr.com/) account; 300MB/mo allowance there.

AntonLargiader
15th of December 2010 (Wed), 06:31
i have no personal website to upload 8mb photos :( do you know of any?

You're expecting us to look at 8MB photos? Crop them to show the area you're concerned about, make them conform to the attachment guidelines, and attach them to your post.

stsva
15th of December 2010 (Wed), 08:00
You're expecting us to look at 8MB photos? Crop them to show the area you're concerned about, make them conform to the attachment guidelines, and attach them to your post.

Exactly. Usually looking at a full image is not very useful anyway, as the sharpness issues don't show up very well. Do a 100% crop (image displayed in your editing software at 100%, then crop the appropriate portion without resizing/resampling) showing the focusing issue. The image guidelines for POTN allow you to directly upload an image that is a maximum of 1024 pixels on the longest side and no more than 150KB in size. Also, provide complete shooting data for the images, including what the intended point of focus was and the focusing mode and focus point selection you were using.

WaltA
15th of December 2010 (Wed), 11:13
Did you check this stickie out yet. Lots of hints there of stuff to do when troubleshooting this kind of question.


http://photography-on-the.net/forum/showthread.php?t=857871

funkyfones
15th of December 2010 (Wed), 11:36
I'l help OP out....

He gave 2 pics, heres the 2nd one

http://img5.imageshack.us/img5/7574/69353245a.jpg

I got the info from DPP and crops mid, left and right

http://img811.imageshack.us/img811/1511/cropsy.jpg

I assume focus point was on cup cos its sharpest there as there was no info in the pic.


and yes I'm bored

tfizzle
15th of December 2010 (Wed), 11:50
looks fine to me if your focus point is in the middle of the frame. Also, ISO 800 will make it a little soft due to the computer generated light making it bit more fuzzy. That's not the best image to see if your lens is focusing off spec.

funkyfones
15th of December 2010 (Wed), 11:55
I think its without any sharpening/CA correction/NR done as well, unless OP says otherwise. Oh and correct me if I'm wrong but couldnt OP have dropped shutter speed to 100ish and lowered ISO as well, or would the LED signs have ghosted?

stsva
15th of December 2010 (Wed), 12:12
The cup looks sharp, but as mentioned above that's not a good image for judging focus accuracy. I think the OP needs to take a look at the link suggested in post 8 above.

Adam Jones
15th of December 2010 (Wed), 12:44
The blurring in the bottom half of the image looks bizarre -- almost like motion blur, to my eyes...but I would think the 1/500 shutter speed would rule that out.

stsva
15th of December 2010 (Wed), 12:54
It was shot at f/2.8 - depth of field may have some impact on what we're seeing, since the stuff at the edges looks a lot closer than the stuff in the center.

tfizzle
15th of December 2010 (Wed), 13:01
you gotta remember that 24mm on FF is pushing wide angle so the edges will have some distortion. Especially at that type of tilt up. I think that's what you're seeing.