Bridge not sharp - why?

[EOBeav]

I have a Canon EF 70-200 f/4 L and a 5DmkII. I've used this setup regularly for awhile now, and I've come across something I can't quite explain. I recently shot this bridge in Oregon. I used a sturdy tripod (Manfrotto ballhead/tripod combo), so stability isn't an issue. Still, several of these images came out much less sharp than I've been used to seeing from this lens. It looks like motion blur to me, but like I said, I was using a sturdy tripod. I shot at f/8, and even one of the images at f/11 had this same issue. Shutter speed was 1/20 and ISO was 125, and autofocus was directly on the front of the bridge itself. I can't imagine this lens is suddenly misfocusing so badly.

I'm at a loss. I ~thought~ I had all three legs on steady ground, but of course anything is possible, and it's possible one of them may have been in some soft ground, slowly sinking during that shutter time. I just don't think that's the case, though. I don't have any other explanations than this. Like I said, I'm used to getting much sharper photos with this lens. I thought I would throw this question out to the many qualified photogs on here. I'm not a beginner, I'm just not sure what happened. Thanks in advance for your helpful comments and suggestions. I'm posting an unedited, straight-from-lightroom- image. You can pixel peep at the full version size here. (2.4MB file)

 

[Mt Spokane Photography]

You can check the lens on a flat building or target and see if it is sharp. There could have been some vibration or motion.

I avoid slow shutter speeds even with IS in favor of higher ISO settings.

 

[EOBeav]

You can check the lens on a flat building or target and see if it is sharp. There could have been some vibration or motion.

I avoid slow shutter speeds even with IS in favor of higher ISO settings.

There's no IS, but I was using a tripod.

 

[bdunbar79]

I would suggest the following. 1/20 is really slow, and you're shooting something really far away. Other things will affect the image and things that a tripod cannot stop. Shutter pressing causes vibration as does the mirror motion. I would try two things. The first, use a remote trigger that plugs into the camera and/or secondly mirror lockup. Like another poster said, if I have to go 1/20 to get a low ISO, I'll forgo the low ISO and typically I won't shoot slower than 1/60-1/80. The tripod cannot stop those two things.

That of course isn't necessarily what's going on, but I just wanted to add to the discussion and that's what I was able to produce. I'll try to think of more things.

 

[EOBeav]

Thanks dunbar...I neglected to mention that I use a cable remote. I pretty much take every precaution I can to keep my camera as still as possible. More to the point, though, was that I was wondering if this kind of non-sharpness was due to motion blur or just not being focused in the right area. To me, it looks like slight motion blur, but I'm not 100% for sure.

 

[jhanken]

On telephoto, setting, the mirror lockup special function gives you an additional way to reduce camera shake, there will be no mirror slap to cause motion-induced blur.

It hard to imagine the setting where 1/20 exposure would be required for such a shot in sunlight, even at golden hour. Are you stopping way down?

 

[EOBeav]

On telephoto, setting, the mirror lockup special function gives you an additional way to reduce camera shake, there will be no mirror slap to cause motion-induced blur.

It hard to imagine the setting where 1/20 exposure would be required for such a shot in sunlight, even at golden hour. Are you stopping way down?

ISO was 125, aperture was at f/8, normally the sweet spot for sharpness on this lens. I normally shoot as far to the right as I can go on the histogram, just before I start blowing highlights. I'm going to do a few tests tomorrow to see what's going on. I'm thinking one of the legs was just in some soft ground (it was fairly wet up there). I'm used to much sharper images than this.

 

[Hillsilly]

Could the cable remote also have triggered the AF at the time of taking the photo resulting in the camera focusing on the wrong spot?

 

[MatthewLewis]

I would bet, due to your location that wind and heat would be the culprit... couple that with your low shutter speed. That would be my bet. That lens is long, no IS, and everything else I mentioned... I don't see how you could get an ultra sharp shot actually, now that I think about it.

Just my thoughts

M

 

[infared]

I have a Canon EF 70-200 f/4 L and a 5DmkII. I've used this setup regularly for awhile now, and I've come across something I can't quite explain. I recently shot this bridge in Oregon. I used a sturdy tripod (Manfrotto ballhead/tripod combo), so stability isn't an issue. Still, several of these images came out much less sharp than I've been used to seeing from this lens. It looks like motion blur to me, but like I said, I was using a sturdy tripod. I shot at f/8, and even one of the images at f/11 had this same issue. Shutter speed was 1/20 and ISO was 125, and autofocus was directly on the front of the bridge itself. I can't imagine this lens is suddenly misfocusing so badly.

I'm at a loss. I ~thought~ I had all three legs on steady ground, but of course anything is possible, and it's possible one of them may have been in some soft ground, slowly sinking during that shutter time. I just don't think that's the case, though. I don't have any other explanations than this. Like I said, I'm used to getting much sharper photos with this lens. I thought I would throw this question out to the many qualified photogs on here. I'm not a beginner, I'm just not sure what happened. Thanks in advance for your helpful comments and suggestions. I'm posting an unedited, straight-from-lightroom- image. You can pixel peep at the full version size here. (2.4MB file)

If you have IS make sure it is off adn hang weight on the tripod and make sure that the weight is not swaying to ad more stability...also...lock up the mirror....basically do everything in your power to make sure your equipment can do its job. If it looks like motion blur...it probably is....I know sometimes we all get caught up in the excitement of taking a great photo...and make mistakes...just try to eliminate all variables....

 

[jcns]

other things to consider
humidity can affect how light travels
distance. the further away you are from the subject the more light diffraction you will encounter

 

[alexanderferdinand]

Far distance can cause problems because if the air between. Not only the moisture, sometimes its a flow of warm or cold air in it that causes blur and the pictures suffers being not sharp.
Telefotos are different; its not just getting things closer.....

 

[cervantes]

After inspecting the full-res image I'm pretty sure that there is no motion blur involved.
The Lens is either bad or misfocused. Luckily this is pretty easy to find out:

Make a picture of something (preferably something flat) by using manual live-view focus with magnification. When you can't get sharp results then there is something wrong with the lens.

 

[SlothLovesChunk]

Eh, this looks like motion blur. Not one thing is in focus, even in what you can obviously see is the focus field. Don't see glare (as if from moisture in the lens).

A few things:
1/20th is waaaay too slow a shutter speed if you're shooting over 70mm...tripod or not. In cinema, even on a 50lb, $20,000 tripod, we never start action until a few seconds after rolling, as you need time for the camera to settle. Remote or not, the mirror flip in a DSLR causes vibration...even when it's locked up, the shutter itself will cause minor vibration. If you're ever in California, like me, you know that there's no such thing as "stable ground". Don't ever count on it. When I shoot long exposures, I always hold a black card in front of the lens before the shutter opens, wait a second, then open it up for exposure...camera shake is a sneaky beast.

125 ISO is way too low. Boost it and increase your shutter speed. Canon sensors seem to be the least noisy in increments of 160, so the cleanest ISOs are 160, 320, 640, etc, so actually 640 will probably have less noise than 125, oddly. There is virtually no significant visible noise until you get past 800...I think even 1250 is very pristine, and better than many of the lower ISOs. Go up to 640 or 800, increase your shutter speed...1/500 and above are pretty safe.

Doesn't really look like a glass issue, but do make sure your filters are awesome. I don't know what you've got on there. L lenses are brilliant and expensive...but the g's you spend on 'em are worthless if you have a murky $25 dollar Japan Optics plexi-glass filter in front of it. B+W/Schneidder filters are immaculate. They're painfully expensive, but they are sharp as a tack and they disappear in front of your lens. I've had a $120 B+W filter take the fall on a volcanic rock in New Zealand for my $1600 L lens, and saved its life. It's like an insurance policy.

Hope this helps. Sloth hates fuzzy images.

 

[Jan]

A few things:
1/20th is waaaay too slow a shutter speed if you're shooting over 70mm...tripod or not. In cinema, even on a 50lb, $20,000 tripod, we never start action until a few seconds after rolling, as you need time for the camera to settle. [...]

125 ISO is way too low. Boost it and increase your shutter speed.

+1

 

[PavelR]

I vote for motion blur (camera [wind...], engaged AF, ...). Try the similar shot (distance, F number) with more light / higher ISO and faster shutter speed - about 1/250 (1/320).

 

[aprotosimaki]

I have a Canon EF 70-200 f/4 L and a 5DmkII. I've used this setup regularly for awhile now, and I've come across something I can't quite explain. I recently shot this bridge in Oregon. I used a sturdy tripod (Manfrotto ballhead/tripod combo), so stability isn't an issue. Still, several of these images came out much less sharp than I've been used to seeing from this lens. It looks like motion blur to me, but like I said, I was using a sturdy tripod. I shot at f/8, and even one of the images at f/11 had this same issue. Shutter speed was 1/20 and ISO was 125, and autofocus was directly on the front of the bridge itself. I can't imagine this lens is suddenly misfocusing so badly.

You say that several of your images came out blurry, which implies that others did not. How do the settings compare between these two sets?

I would suspect mild shake due to the wind or the mirror flipping up. As others have suggested mirror lockup could address this. But it might just be that your AF had a rough day. Did you try manual focus as well?

 

[AudioGlenn]

I have another idea (laugh if you want).

If the camera isn't moving, and the air/humidity isn't what's affecting how the light hits the sensor, wouldn't it be reasonable to think that the bridge might have some slight movement? maybe enough flex in the wind to show motion blur at 1/20? I mean, the top tip of the Empire State Building sways from side to side. Either the bridge is moving slightly or the platform you're standing on is moving. Any civil engineers on the forum?

 

[sandymandy]

I think metal buildings can sway but not concrete buildings like the bridge in the photo.

 

[weixing]

Hi,
How heavy is your tripod? Make sure your tripod is steady and your setup is heavy enough... if you are using those carbon tripod, your setup might not be heavy enough to prevent the slight shake that cause by wind, people walking nearby & etc. You didn't see your camera shake, doesn't mean the camera didn't shake... at 1/20s, a slight shake during the exposure can cause your image to be blur. You can use the hook (a lot of modern tripod had that) below the tripod to hang something heavy to increase the weight of the setup.

Best is to increase your ISO to get a higher shutter speed. If not, I recommend you to use live view to focus at the object using 10x, make sure everything is lock down and make sure you see that the image is perfectly still before you trigger the shot... also, try to be as still as possible when trigger the remote cable... don't laugh... during some macro shot, I can see the image shake a bit in live view when I move my feet a bit.

Also, the blur might be cause by air turbulence which is very possible by looking at your image... the temperature different between the heated stone bridge and the cooler environment in the shadow might create some air turbulence which blur the image.

Just my $0.02.

Have a nice day.