does over exposing too much make you loose detail ?

[Corey Hayes]

Hi everyone I have a question on proper technique. Today I was taking pictures of hawks and eagles and the sky was grey and overcast. I was shooting in AV mode at f 5.6 and to get the bird to have any detail I was over exposing by 2 but I have noticed that I don't really have good pictures. They are all fuzzy. The birds were 30 or 40 feet away and they still show up fuzzy even when using high shutter speeds. I was told today you should not go much above 1 stop. I also noticed that whenever the bird would have a blue sky behind it the pics would be sharp but with the grey sky I get that soft look. I am using the 7D and 500 f4.

Basically just wondering how you guys would approach the situation

thanks

[Jon Rista]

Could you post some examples, or at least links to examples, that demonstrate the issue you are seeing? I wouldn't expect an EC boost to exposure to be the cause of the problem. When photographing birds (particularly darker birds) against a lighter background (such as a gray sky) it is not uncommon to compensate with +2 EV. If you are getting consistently fuzzy photographs, you probably have another issue. Your ISO may be too low (when photographing birds in flight its rare to be able to use ISO 100), which will usually require a longer shutter speed. Too long a shutter speed and either camera shake or the motion of the bird, or both, will blur the results.

[Corey Hayes]

Hi here is an example, I loaded up DPP to check the AF points and two where on the body of the of the harrier that is fuzzy and the top sharper one has one near the head.

The fuzzy picture had a shutter speed of 1600 and the top most one has 1250, but I have ones that are 3000 or more and still fuzzy, so it has to be AF related.

I have my 7d set up with how Arthur Morris recommended in his 7D user guide and I am using 400 iso and 800 if I really need the speed.





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[Ulli Hoeger]

Overexposing by 2 f-stops and compensating exposure by 2 f-stops are two different things.
The first will lead to a very bright, wrongly exposed subject, the second to a correctly exposed subject in an image that would have been otherwise underexposed in respect of the subject.
If you would set exposure manually in this situation you would set the required exposure number that you have to "force" on aperture or time priority modes by dialing in compensation.

I assume you did the 2nd one to compensate for the bright bg and if you didn't have to tweak the resulting image excessively in post processing to get a properly exposed image, i.e. the exposure was reasonably close, your problem is not due to the use of exposure compensation.

One reason I would explore in a case of fuzzy images, even with fast shutter speeds and technical spot on AF, is the possibility of turbulences in the air caused by e.g. temperature. Even on short distances this can be so severe that AF will be unable to find a lock, or blur the shot in the split second between AF lock and shutter opening completely or in part. The severe cases are obvious and noticable by the naked eye, the sneaky ones can be hard to notice in advance.
I recently got a few shots of a heron in a pond only ~ 20m away with parts of the heron sharp in focus and parts on the same focal plane being fuzzy and blurred. Other frames in the same series of shots were completely in focus. The problem was both spatial as temporal variable.
It was an overcast late afternoon outing with moderate daytime temperatures. I wasn't expecting turbulences to be an issue and by eye non were noticable, even when looking through the viewfinder not many clues to possible issues in this departtment and AF locked on the target with no problems. Still a couple of dozen frames had to go straight into the bin, and I learned another lesson .........

Ulli

[arash_hazeghi]

Cory,

Soft images can happen for many reasons. In your example lack of sharpness is not due to bad exposure although the light was quite harsh and not ideal for making detailed images.

BIF is not a trivial point-and-shoot job, many people struggle to get sharp flight shots. You need to to work your technique and get a good feel of when the camera locks on the subject and when it does not and what to do to increase your chances. Putting the AF sensor on the bird doesn't guarantee the AF will lock on the bird.

Another factor is heat refraction that can cause soft images. You won't see this effect in the finder but if you put your camera in LV and try to focus on a stationary subject at identical distance the image will look hazy. Best time to photograph birds is before sunset or after sunrise when temperatures are cooler and sun is lower in the sky, there is less atmospheric refraction effect.

good luck

Arash

[Jon Rista]

Corey,

Based on the two sample photos you posted, I am not inclined to say the issue is a result of exposure. Motion blur exhibits in a certain way, however your shots appear more out of focus than motion blurred. It might be blur because of camera shake, assuming you were hand-holding without IS.

I recently had a very odd experience with an EF 300mm f/2.8 L II IS lens and my Canon 7D. It was a rental lens from LensRentals.com. I'd recently purchased Reikan FoCal Pro, a tool that is capable of automatically tuning the cameras AFMA setting. I ran the lens through an aperture test the day I received it, and found that its resolution was far lower than that of my 100-400mm L, when the results should have been the other way around. After a lot of fiddling and retesting, I finally checked the AFMA setting in the camera itself. It was -92, on a scale from -20 to +20. I had similar results as you when trying to photograph anything...every shot looked a little soft. It took a reset of the camera to factory settings to eliminate the issue and set the AFMA setting for the EF 300mm f/2.8 L II to 0. Once that was done, focus was spot on every time.

[Corey Hayes]

Thanks guys I think a large issue was the haze since you could see it when you looked out over the field, I had the same problem today once it warmed up,I didn't know it could screw your images up so much.

When I had my 300mm I was always close to the subject and it was the cooler months so I guess I never noticed it that much.

[Roger Clark]

Corey,
Just to confirm, you are in AI servo, correct?

Roger

[Corey Hayes]

Yes that's all I use.

[Roger Clark]

Hi Corey,

Then I'll agree with others: it is probably atmospheric turbulence.

Roger

[RSchmidt]

Corey,

Based on the two sample photos you posted, I am not inclined to say the issue is a result of exposure. Motion blur exhibits in a certain way, however your shots appear more out of focus than motion blurred. It might be blur because of camera shake, assuming you were hand-holding without IS.

I recently had a very odd experience with an EF 300mm f/2.8 L II IS lens and my Canon 7D. It was a rental lens from LensRentals.com. I'd recently purchased Reikan FoCal Pro, a tool that is capable of automatically tuning the cameras AFMA setting. I ran the lens through an aperture test the day I received it, and found that its resolution was far lower than that of my 100-400mm L, when the results should have been the other way around. After a lot of fiddling and retesting, I finally checked the AFMA setting in the camera itself. It was -92, on a scale from -20 to +20. I had similar results as you when trying to photograph anything...every shot looked a little soft. It took a reset of the camera to factory settings to eliminate the issue and set the AFMA setting for the EF 300mm f/2.8 L II to 0. Once that was done, focus was spot on every time.

Jon, What is an "AFMA" setting? AF I suspect is AutoFocus and MA.........Manual??

[Jon Rista]

@RSchmidt: AFMA stands for AF Micro Adjustment, a feature found on a variety of middle- and higher-grade DSLR's. It allows you to fine tune the focus plane in the camera by lens to offset any slight missmatch. If AFMA is off or set inforrectly, it can result in every single shot looking soft or slightly OOF.

[Jim Neiger]

Corey,

I think Arash has led you in the right direction. The problem appears to be that you were not focused in the correct focal plane to get the bird sharp and that is why it appears out of focus. This is a very common problem when shooting bif. This often happens even when the af point appears to be on the subject in the resulting picture. Where the camera is actualy focused and where the af point appears in the resulting image are often different. This can occur if you move the focus point away from the bird, the bird's distance from you changes, you put the af point back on the bird and trip the shutter before the camera can dial in focus on the bird. The delay from the tracking sensitivity CF can make the time it takes to re-focus long enough for this to occur readily and often. You can overcome this problem be realizing the af point has wandered off the subject and then bumping the focus to return focus to the bird immediately with no delay. It is very easy to not realize you have lost focus, so you need to watch this very carefully to identify the problem when it occurs. I hope this helps.

I don't think it's an atmospheric problem at a distance of 30-40 feet. I have images made at a greater distance in fog that are much sharper than these.

[Jon Rista]

To further @Jim's answer, if you have a newer Canon camera like the 7D (which I believe the OP does), or the 5D III and 1D X, you can use a different AF mode to help you keep your subject in focus. All three of those cameras support single-point AF, as well as Expansion AF and Zone AF. Expansion AF allows you to select a single AF point, however the AF system will utilize the 4 surrounding points (above/below & left/right) to assist in maintaining focus on your tracked subject if the selected point strays off. Zone AF is a multi-point AF mode that allows you to select a sub-zone of AF points rather than all 19 (or 41/61 in the case of 5D III/1D X).

Additionally, you might want to tune your AF system to react more slowly to changing content under the selected AF point/zone. In the 7D's C.Fn III (Autofocus/Drive) settings, you might want to play with 1 AI Servo tracking sensitivity. This affects how quickly the AF drive system will decide to abandon the current subject it is tracking in favor of another when your main point strays. I set mine to slow, or one notch to the right of slow, for BIF where the bird is largely transitioning. If you shoot birds that are flying right at you, you might want to set that to zero (center). You might also want to try setting 3 AI Servo AF tracking method to "Continuous AF track priority" rather than "Main focus point priority". The former instructs the AF drive system to support subject tracking, at the expense of always keeping whatever is under your selected AF point in focus. Finally, you should make sure that 2 AI Servo 1st/2nd img priority is set to "AF priority/Tracking priority". This will instruct the AF drive system to assure that the subject is focused, and put a greater weight on maintaining subject tracking, before allowing the next exposure to take place. This may slow down your frame rate a bit, but it can help increase your keeper rate. The other options either increase drive speed weight, which aims to maximize frame rate, or they aim to give the photographer total control over when exposure takes place (Relase, for "shutter release".) The latter two options result in a very low rate of keepers for me. If you prefer having direct control over when exposure occurs, and you have confidence in your ability to control the shutter, then the latter two options might be better for you. Generally, as you move down the list for C.Fn III # 2, the more the camera gives priority to maximizing frame rate over achieving AF success, so your keeper rate is also likely to fall more the farther down that list of options you select.

[RSchmidt]

To further @Jim's answer, if you have a newer Canon camera like the 7D.........

Jon, thank you for response to my first question and then expanding on this point. I do have a 7D. I'm a new user however, still becoming familiar with all the controls. Your paragraph above is very helpful. Thank you!

Rog

[Kerry Perkins]

Corey, are these images full frame? If DPP shows that the camera found focus at those points then there is something else going on here. To be sure that your camera and lens are performing at their best, take a page of newspaper and attach it to a wall or fence. Capture some images in the same way that you captured these birds. If the images are sharp then you know that the gear is not to blame. The color of the sky has nothing to do with focus.

[Jamie Douglas]

From my two and a half year experience with the 7D for BIF and judging from the IQ in the examples, I think this is purely a technique issue. It looks like the AF just hasn't locked on the subject. But your not alone. I have had my fair share of soft images like these and it takes a bit of experience to nail the type of images you'll see in these forums. Good luck and dont be put off. The peristence will pay off and you will love the rewards. You have a great combo and once you perfect it... JACKPOT!

But before I judge, do you have some examples of images you are happy with that we can compare? Overexposing shouldn't impact your images as much as the examples above, they should still be sharp but may lack a wee bit of detail.

[Jon Rista]

@RSchmidt: Glad to be of service. :)

[Bill Jobes]

Hi Corey,

Throughout this thread I've been intrigued by you saying that the birds were '30 or 40 feet away' -- and no one questioning it.

I know it's a guess, but, are you sure? That is pretty darn close and may have been a factor if you didn't nail the focus point right on the birds.

Also, are the two images full frame, or cropped ?

[Corey Hayes]

Hey guys, I have been out alot since and when I took these pictures I now believe it was do to the heat waves, its very noticeable on a lot of days now. I did some tests shooting a sign or a boat in the water near the cliff and when it was hazy the sign or the boat ended up looking very soft. On clean days I have had much better luck.

These shots where 70% full frame, so there where pretty close.