View Full Version : Focusing sharpness dilemma

15-10-2010, 3:02pm
Hi Everyone,

I'm relatively new to photography as far as playing with apertures, exposures and ISO settings goes. Although I'm comfortable with the theory, I seem to be constantly having trouble with my photos, particularly getting sharp images.

I have a Canon 40D with a EFS 17-55mm F2.8 USM IS lens, which I understand is a reasonable combination for someone of my limited experience.

I primarily kick around wetlands and lakes, and mostly take photos of plants, wide angle landscapes and the occasional animal.

I generally flick between the automatic settings and Av (aperture priority?) when taking photos, and normally leave the auto focus and IS on. In most cases, I can see why many of my dodgey photos have not worked, ie, too low F setting, incorrect ISO selection etc.

One thing that has concerned me is that my photos seem to lack focal sharpness when I bring them up to 100% resolution on my computer. This is particularly the case for vegetation shots and landscapes.

I'm not sure whether I'm expecting too much from my camera combination, whether my camera settings are constantly wrong or whether my lens is dicky. When I use the flash, most of my closeup photos turn out reasonably sharp, indicating that it is likely to be me that is the problem.

I've pasted a number of photos below to illustrate my problem. I've read a number of other posts which have mentioned calibrating the camera and lens, but I'm not whether this is the reason for my lack of sharpness. The photos taken using the flash tend to be reasonably focused which suggests that it must be something that I'm doing which is mucking up my photos.

F16 1/25 ISO200 - sunny conditions, lizard head not sharp

F7.1 1/400 ISO400 - overcast but bright light

F8 1/500 ISO400 - overcast

I would be very appreciative of any suggestions. I'll post a couple more photos later when I have a bit more time.


15-10-2010, 3:40pm
Could you possibly post a 100% crop so we can better see how sharp (or not) the photos are? It's impossible to tell sharpness from a web-sized shot.

Also, are you adding any sharpening in the camera or in post processing? All digital images need some sharpening to look their best and bring out the details.

The 1/25 shutter speed on the lizard is quite low, and depending on what focal length you were using and how steady your hands are it may have been too low to avoid camera shake, even with IS on. (I don't have any experience with IS/VR/OS so don't really know how effective it is). Also, where was the focal point in the photos?


15-10-2010, 5:20pm
Have a read of this : http://www.ausphotography.net.au/forum/showthread.php?8579-Why-all-Digital-images-need-SHARPENING

15-10-2010, 5:45pm
Hi Rick,
Many thanks - I'll certainly give sharpening my photos a go. I had read another thread where you discussed manipulating the RAW images. It looks like I need to head back to the books on this one.

15-10-2010, 6:01pm
Hi Paul,
Thanks for your reply. I've posted some 100% crops from a range of photos that I have concerns with. The images shown are all the focal points of the respective photos. Whilst going through my photos again, I have started to realise that the F settings that I'm using are generally too low (<6.3) or high (>14) for many of my general shots. I have started to realise just how important the aperture selection is to getting sharper photos. Your comment regarding the shutter speed on the lizard is spot on .. the IS probably wouldn't make that much difference at that speed, and using F16 for such a photo is way over the top.

The ISO numbers that I am using are also probably too high. This is complicated by the fact that the 40D seems to default to a higher ISO setting in sunny conditions (ie 400) - I need to more conscious of this when taking photos.


1/400 F10 ISO400

1/500 F8.0 ISO400

1529 1/400 F7.1 ISO400

1/320 F9 ISO400

1/250 F8 ISO200

15-10-2010, 6:14pm
Here's a few more problem shots illustrating my focus issues, also at 100% crop.

1/500 F8 200

1/400 F8 400

1/25 F16 200

15-10-2010, 7:08pm
For day shots stick to 100 ISO , If there is fast action go to 160 ISO , f8 to f11 should do the trick , Try f6.3 for the action shots @ISO 160 , With these settings the shutter speed should be high enough to easy use Handheld and stop the action , Keep on checking the in Camera Histogram to check the exposure :)

16-10-2010, 9:59am
G'day Jase

Thanks for sharing with us your images & your concerns
Looking at the 100% crops though, they seem [esp the lizard] to "be as sharp as you're likely to get under the circumstances"

You have noted 1/25sec for the lizard ... not many of us can hand-hold with perfect stillness at 1/25 second
I would also ponder upon "where in the image have you / is the camera actually focussing??

In almost all of my images, I will focus on something that is not in the centre of the framed image -
ie: I will swing the camera to & fro to work out my framing [rule of thirds etc etc] before targetting 'something', 1/2-pressing the shutter button to focus on it [and getting the 'beep'], and without releasing the button, sweep back to my framing location I then fully press the shutter to take the photo

Does this help at all?
Regards, Phil

16-10-2010, 10:28am
You need to narrow down the problem i.e is it in the camera/lens or is it just a complaint about how they look over the net when posting ?? These are two different issues.
1. Does it look sharp in the viewfinder when taking the picture with the camera solidly stable ?
– if it does, it is very unlikely to be in your camera/lens
– If it does not – try manually focusing to see if you can get it looking sharp in the viewfinder – if you can, it is then likely to be an autofocusing problem/calibration. If you cannot (provided minimum distances are met), it is an equipment problem

2. You need to eliminate the above equipment failures first. If you can get it looking sharp in the viewfinder, then, subject to shutter speed minimums, the problem may be with post processing and specific preparation for posting on the web.

3. From what Mongo can tell of the images you have supplied, they look genuinely unsharp as if not processed fully. They do not look like camera shake/slow shutter speed issues.

16-10-2010, 11:02am
To be honest, you really need to learn the factors relating to sharpness and then progressively eliminate each one or see how much each one is relevant to you and your type of photography.

Some things that come to mind, but I'm sure I've left out many more;

1/ Lenses have an optical 'sweet spot' so try to stay within that range. Test your lenses and find out where they perform below your needs and then work with that. Generally speaking, if you stop down about 2 stops, then you will be near optimal performance. If you shoot at F16, 22, 32 then image quality will be reduced. This applies to $10,000 lenses as much as it does to $100 lenses. You can't change the laws of physics by spending more money. I have some lenses that perform almost as well wide open as they do stopped down but the laws of physics show themselves and there is always, always an improvement when stopping down a little, maybe only 1 stop.

2/ You probably can't hand hold a lens as well as you think you can. Consider camera shake and the effect this has. Try to use a tripod whenever possible (it helps with composition too). Test your OWN ability to hand hold a lens at different shutter speeds and find out where the line is for you. As an example, I know that if I want razor sharp images with a 50mm lens or longer than I really need to be shooting at 1/250th of a second or shorter. That doesn't mean that I can't get acceptable results at 1/8th sec, I can, but it will never be razor sharp. There are other factors such as the camera itself, but it's worth testing. IS may give you a false sense of confidence too. If you can, fire off a few shots of each frame so that if camera shake is an issue it is less likely to affect every image that you shoot in a short burst.

3/ If your subject is blowing in the wind, grass, trees, it will never be sharp.

4/ Don't ever use a higher ISO than you need to. Shooting at ISO 400 will definitely reduce sharpness, no ifs, no buts, your image will be less sharp. I even use IOS 100 when shooting in near total darkness at night. Also avoid intermediate ISO settings, 125, 160 etc., as on some cameras this results in worse noise performance than whole stop settings (or so I have read, I've never etsted it personally).

5/ Your ability to actually focus accurately will always be a factor too. Your 40D has live view which allows you to focus perfectly. Using AF can introduce focusing errors and focusing manually (my preference) is generally more accurate but is subject to errors too. Live view is 100% so use that if you can.

Do some testing, you'll probably learn quite a lot along the way.


16-10-2010, 11:07am
As Mongo said but the lizard shot is due to motion and or camera blur with a moving subject

Try focussing on a stationery object which is vertical to the plane of the camera
Use single and central point
Tripod mount or at least a shutter speed of 1/200s

If you are not sure why your camera is auto adjusting iso to 400....I suggest reading the manual some more and I think a good idea would be to follow the new to photography program on ap to really start understanding the exposure triangle

16-10-2010, 9:53pm
JJphoto hit the nail on the head for me. :th3:

the 100% crop of the lizard shot doesn't look that bad actually!

I downloaded it to my PC, and using my software(CaptureNX not PS, so comparative purposes are useless) but, I added a very light USM and it looks quite good, for a 100% crop!.. maybe a very slight lack of contrast(maybe f/16 on that particular lens reduces contrast in the image... as well as burdening the image with some diffraction.

first up; have you sharpened the images at all, in any way?
if so, then .. ok.. not as sharp as one would expect. did you shoot raw or jpg?
if you shot raw, did you sharpen the raw file?(before you converted to jpg).

have a look at THIS (http://www.ausphotography.net.au/forum/showthread.php?8579-Why-all-Digital-images-need-SHARPENING&highlight=images+sharpening) post from Rick as to what processes help to make a sharp image too.

definitely start with the basics that JJ explained tho.

(general question) is there a way to stop photoshop destroying all exif data in the output image.
I've noted that some images(usually ones not edited by photoshop) contain a lot more exif data(not just info) that photoshop always seems to destroy. really hinders the ability to provide more detailed feedback based on images posted up as examples.

17-10-2010, 12:09am
I'm relatively new to photography as far as playing with apertures, exposures and ISO settings goes. How about selecting Focus Points?

I have a Canon 40D with a EFS 17-55mm F2.8 USM IS lens, which I understand is a reasonable combination for someone of my limited experience. / I'm not sure whether I'm expecting too much from my camera combination, whether my camera settings are constantly wrong or whether my lens is dicky. All things being equal you should be able to achieve "Razor Sharp" images with this combo!

I primarily kick around wetlands and lakes, and mostly take photos of plants, wide angle landscapes and the occasional animal. You should be able to get sharp shots of a single plant/animal at around f5.6-f8 but for large groups or landscape shots you need to be up around f16-f22 to get 'everything' in focus.

I generally flick between the automatic settings and Av (aperture priority?) If you shoot in any of the Auto modes you cannot select the focus points!

I'm guessing a major contributor to your problem is not selecting your focus point (the little red square(s) that lights up in the viewfinder). This tells the camera where YOU want the primary focus to be. Particularly at larger apertures, the camera cannot have the foreground & background in focus simultaneously! In the auto modes the camera makes this decision for you, often getting it wrong, eg. focusing on the branch nearest you instead of the animal you're after a bit further away. (Tip: If you open your original shots with DPP, under View Tab is an option to show focus point.)

When in Av mode press the "AF point selection" button (top right corner, 5 dots in shape of +) now turn either dial and you will see the camera scroll through the different focus points, stop at the centre one. With the wonderfull 17-55 being f2.8 you get 'double' precision accuracy with the centre focus point!

Now position that centre square on your lizard's eye (or other point of interest) and take your shot.

Good Luck

17-10-2010, 10:26pm
Hi Guys,

My sincerest thanks for all of your valuable feedback. In the process of going through selecting the images to show and reading through your suggestion, I'm feeling a more empowered to keep plugging away.

The photos that I provided have not been sharpened and were taken directly from jpg's. I was originally shooting in both raw (after reading one of Rick's posts on post processing), but have recently been just taking jpg's in order to try and sort out my focusing and composition issues. Going by everyone's feedback, I looks like I need to start post processing my photos in order to get the best out of my shots - back to raw format.

I recently changed the AF point selection from the 5 dots to the centre one when in AV mode. It has certainly made a difference. I'm constantly maxing out the focal length of the lens, and I'm wondering whether I should be considering a longer focal length lens?

It also looks like I'm going to have to do some more homework on my aperture and exposure selections.

Many thanks again.