Is my lens faulty?

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Hi everyone, I've just joined today so please accept my apologies if I've posted this in the wrong place or asked something I shouldn't have.

I recently purchases a secondhand lens: Canon EF 70-300mm 1:4.5-5.6 L IS USM

I noticed that my shots are relatively sharp at close(ish) range, but really far away distant objects are never sharp (mountains, buildings several miles away, the moon etc..).

I'm wondering if the lens has a problem capturing sharp images at a long distance (would you call that infinity?).

To test this, I sat my camera (6d) on a tripod and manually dialled in the settings, switched off IS, and focused on the moon. The image appeared sharp on my camera LCD, but it's not sharp when brought into lightroom.

Other tests I've done are during the day focussing on buildings around 10 miles away, both handheld and on tripod (with IS switched on). I've also tried shooting moving birds, and none of these are sharp (but I accept that might be due to my lack of experience here).

I noticed the focus distance indicator on the lens moves only to the start of the "|______8" indicator, never beyond (unless I manually change it), if that helps,

I'm not sure the best way to add some sample images (if that helps?).

Are there any other better ways to test the lens?

Could I just be expecting too much from my Lens (or camera)?
 
Hi Stuart,
For your moon shot, what were your settings?
Did you use the timer to activate the shutter?
Did you try manual focus?

Oh, and... :welcome:
 
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I found the optimum settings (according to the LCD display): ISO 50 (also tried 100), f/5.6, 1/50 sec at 300mm.
Had 2 second timer activated with remote.
 
Hi and welcome to TP

The original 70-300mm was very good but not "the sharpest knife in the block" so to speak. EDIT ooops! I just realised that you said it was the L version....that AFAIK is stellar performer!

So, firstly where you say " The image appeared sharp on my camera LCD, but it's not sharp when brought into lightroom" Are you using LiveView to to focus and take the photograph? Or do you mean you focus through the viewfinder and then fire the shutter, then examining the shot on the camera LCD before importing it into LR?

Next, just how large are the buildings in the image.......................when a subject is at any distance you have atmospheric effects that will soften any image!
 
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Shutter speed is too low.
The moon is quite bright. I find I usually use 1/250 or thereabouts....
Did you use the timer to activate the shutter?
If not, you can still get some vibration that will affect the image.....
 
A couple of things come to mind. 1st, if you're meaning that you are zoomed in at 300mm, then I would expect there to be some softness. As a rule, consumer lenses (as I call them) tend to be softer at the long end of the zoom range.
2nd, atmospheric conditions also have an effect. Warm days, will evaporate moisture in the ground, making a slight haze.
Edit- ignore my first point, as I realise you've got an L lens. Which should be pretty sharp all the way through.
 
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Shutter speed is too low.
The moon is quite bright. I find I usually use 1/250 or thereabouts....
Did you use the timer to activate the shutter?
If not, you can still get some vibration that will affect the image.....

He does answer that he used a remote with the 2s timer ;)
 
A couple of things come to mind. 1st, if you're meaning that you are zoomed in at 300mm, then I would expect there to be some softness. As a rule, consumer lenses (as I call them) tend to be softer at the long end of the zoom range.
2nd, atmospheric conditions also have an effect. Warm days, will evaporate moisture in the ground, making a slight haze.

He did post that it was the L series version...............so a tad above 'consumer grade' :)
 
It just sounds like a lack of experience/technique and unrealistic expectations. Keep in mind that if you photograph something 10 miles away you then have 10 miles worth of smog/haze/humidity/etc in the way. You'll almost never get tack sharp images at that kind of distance during the day.
I found the optimum settings (according to the LCD display): ISO 50 (also tried 100), f/5.6, 1/50 sec at 300mm.
Had 2 second timer activated with remote.
1/50 is about perfect to record mirror slap vibration... you probably needed to use mirror lock-up and a 10sec delay.
 
Thanks for all your replies and suggestions.

Nostromo, sk66, I agree that it could be atmospheric conditions and I could be expecting too much.

sk66, my camera only offers 2 second delay, but I will check out menu options to see if this can be altered. I thought having live view enabled would lock-up the mirror?

Edit: I should have mentioned that I tested at different speeds from 1/50 all the way to 1/2000. 1/50 - 1/400 show about the same quality, anything above had too much noise (high ISO).
 
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Thanks for all your replies and suggestions.

Nostromo, sk66, I agree that it could be atmospheric conditions and I could be expecting too much.

sk66, my camera only offers 2 second delay, but I will check out menu options to see if this can be altered. I thought having live view enabled would lock-up the mirror?
They usually offer 2s and 10s
 
I noticed that my shots are relatively sharp at close(ish) range, but really far away distant objects are never sharp (mountains, buildings several miles away, the moon etc..).

This is probably down to atmospheric turbulence. It doesn't matter how good a lens is if the air between you and the subject is distorting the image. This effect is much more noticeable with longer focal lengths, and tends to get noticeably worse when there's more air in the way!
You should get best results on cool calm days & with the moon high in the sky when shooting the moon.

:welcome:
 
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I thought having live view enabled would lock-up the mirror?
Depends on the camera and if live view is showing exposure preview or not. On some cameras the mechanism that that stops down the aperture is tied to the mechanism that flips up the mirror. Electronic front curtain could make a difference as well... there are different behaviors and I don't really know Canon very well.
 
I found the optimum settings (according to the LCD display): ISO 50 (also tried 100), f/5.6, 1/50 sec at 300mm.
Had 2 second timer activated with remote.

Optimum settings could also be ISO800, f5.6 at 1/800 sec. to reduce camera shake with IS off. The lens may be fine, but image quality can be reduced much more easily through user technique with a longer lens compared to a shorter focal length.
 
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