eskillawl
Topic Author
Posts: 93
Joined: Wed Jan 04, 2012 6:31 pm

What's The Problem With My Lens?

Sat Oct 13, 2012 9:15 am

Good morning, I've got a problem that I would need to fix, but actually cant.

So, for the first I got a Canon 70-300 IS USM lens that i bought on B&H in New York last month. When I frist tried the lens at JFK, it worked out just fine, the pictures was sharp even trough it was cloudy and the photos was taken trough a window. I'll show i a photo.

http://i45.tinypic.com/9sz60z.jpg

But when I got home to Gothenburg, Sweden and started to spot at my local airport (GOT) I noticed how the photos were imo really bad sometimes. Almost every photo is now blurry and dark, and it seems the photos get more worse every time i take photos. I'll show you a photo from the last week. And also, the settings is almost the same in booth photos.

http://i49.tinypic.com/nzm8ht.jpg

What do you think the problem is? It's really sad, cause beofre I bought the lens i read all over the internet about it, and everyone told me it would work better than ex Canon 55--250 IS.

Thanks!
Photo equipment: Canon EOS 60D | Canon 70-200 F4L USM | Canon 18-55 3:5-5:6 |
 
vikkyvik
Posts: 11861
Joined: Thu Jul 31, 2003 1:58 pm

RE: What's The Problem With My Lens?

Sat Oct 13, 2012 9:28 am

Well, according to the EXIF data, the 2nd shot was taken at 235mm, while the first was at 200mm. My copy of the 70-300 IS USM got very soft at long focal lengths (mine was basically unusable beyond 260mm, but maybe yours gets softer earlier).

With that said, even at 300mm on my lens, I don't think I ever saw anything quite as soft as your Thomas Cook shot. Even the Delta shot is quite a bit softer than I would get at 200mm.

Obvious things to check:
1.) The lens is on autofocus (or that you've manually focused correctly).
2.) Focus mode is Servo (assuming you want to use that, otherwise you'll have to keep refocusing as the airplane moves toward/away from you). The Thomas Cook shot might be out-of-focus, rather than soft-but-in-focus.
3.) IS Mode - for moving targets, it's better to use Mode 2. You don't want the camera trying to correct for your panning.
4.) You're using the correct focus points. I usually only use the center one, so that as long as I keep that point on the airplane, I should be fine. If you use more than that, make sure the camera is focusing on the airplane.
I'm watching Jeopardy. The category is worst Madonna songs. "This one from 1987 is terrible".
 
eskillawl
Topic Author
Posts: 93
Joined: Wed Jan 04, 2012 6:31 pm

RE: What's The Problem With My Lens?

Sat Oct 13, 2012 9:41 am

That's what i noticed. When searching on this lens on A.net, you'll get several of great photos, with the same type of camera as me, not as near as bad as my photos.

I've always used AI Focus, I'll try AI servo. Also I use IS mode 1, booth on moving and not moving aircraft, I'll go for mode 2 tomorrow. May theese factors be the problem? I'll defenitively try this when i go spot tomorrow! Thanks
Photo equipment: Canon EOS 60D | Canon 70-200 F4L USM | Canon 18-55 3:5-5:6 |
 
trvyyz
Posts: 1331
Joined: Thu Oct 21, 2004 9:19 am

RE: What's The Problem With My Lens?

Sat Oct 13, 2012 3:02 pm

I have used that lens from when it was released to 2009 and was very happy with it. It was plenty sharp and acceptably sharp even at 300 mm for my copy. The lens is one of the best non L zoom lenses from Canon, much better than a 75-300mm or 55-250mm IS, I have owned all these at different times.

From the above shot the AF didn't lock on to the subject correctly. It could be the user (or settings), camera or the lens.
try the lens with a different body also if the trouble shooting with the settings doesn't workout.
 
kl692
Posts: 636
Joined: Sat Feb 25, 2006 11:34 am

RE: What's The Problem With My Lens?

Mon Oct 15, 2012 6:11 pm

I also notice on your Thomas cook, it was shot at 1/400, try to get it from 1/500 and up.

Ernest
A310, A330,A346,B73H, B747,B772,B77W,CRJ
 
eskillawl
Topic Author
Posts: 93
Joined: Wed Jan 04, 2012 6:31 pm

RE: What's The Problem With My Lens?

Mon Oct 15, 2012 8:46 pm

Thanks, but the problem is i shoot at AV, and than i cant choose shutterspeed at my own, and the camera always choose very very low of some reason. Does anyone know why?
Photo equipment: Canon EOS 60D | Canon 70-200 F4L USM | Canon 18-55 3:5-5:6 |
 
trvyyz
Posts: 1331
Joined: Thu Oct 21, 2004 9:19 am

RE: What's The Problem With My Lens?

Mon Oct 15, 2012 9:08 pm

Quoting eskillawl (Reply 5):
Thanks, but the problem is i shoot at AV, and than i cant choose shutterspeed at my own, and the camera always choose very very low of some reason. Does anyone know why?

In Av mode you can increase the shutter speed by reducing F stop, increasing ISO or decreasing EV.
But, I'm not sure how you shoot, you should be in control of the shot rather than the camera controlling the shot.
The camera does a lot of things to determine the optimum shutter speed (ie, algorithm done by canon engineers depending on your settings), I don't want to go into details. but to check the lens try manual exposure mode and check sharpness for different apertures and focal lengths (keep the shutter speed faster than the reciprocal of focal length ie; 1/200 @ 200mm), have a well illuminated subject and reasonable ISO preferably below 400.
There are also videos on youtube showing how to check the AF precision, whether it is backfocus or front focus etc.
 
vikkyvik
Posts: 11861
Joined: Thu Jul 31, 2003 1:58 pm

RE: What's The Problem With My Lens?

Mon Oct 15, 2012 10:28 pm

Quoting eskillawl (Reply 5):
Thanks, but the problem is i shoot at AV, and than i cant choose shutterspeed at my own, and the camera always choose very very low of some reason. Does anyone know why?

Well, the very basic answer is because the camera doesn't see much light coming in, so it lengthens the shutter speed, since that's the only variable it controls in Av mode.

Trvyyz's post discusses what you can do about it. A quick test would be very simple - shoot in full manual mode. You're already controlling aperture and ISO in Av mode; it's not much of a jump to take control of shutter speed, too.
I'm watching Jeopardy. The category is worst Madonna songs. "This one from 1987 is terrible".
 
unattendedbag
Posts: 2154
Joined: Wed Oct 08, 2003 10:35 pm

RE: What's The Problem With My Lens?

Mon Oct 15, 2012 10:33 pm

Quoting eskillawl (Reply 5):
Does anyone know why?

Did you pack your lens in your checked bag for your return trip home?
Slower traffic, keep right
 
dazbo5
Posts: 2717
Joined: Tue Mar 29, 2005 8:05 am

RE: What's The Problem With My Lens?

Tue Oct 16, 2012 6:12 am

An even simpler method is to just take a few shots of anything static in Av, Tv, manual or automatic, it doesn't matter. It doesn't need to be an aircraft, just anything. If there's a problem with your lens, any shot will come out out of focus or display whatever the problem is. I would be surprised if motion blur is an issue in your example above given the shutter speed was 1/400, but how's your panning technique? It takes practice to acheive good panning even at moderate shutter speeds, especially at longer focal lenths and where some heat haze may make it difficult for the camera to lock on to subjects. There might not be anything wrong, it could simply be you were pushing your lens too much given the conditions. Have a go at a few static test shots and report back.

Darren
Equipment: 2x Canon EOS 50D; Sigma 10-20 EX DC HSM, 50-500 EX APO DG, Canon 24-105 f/4 L, Speedlite 430EX

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