topic Re: Please Help - why are pics not in focus and sharp? in EF & RF Lenses

Please Help - why are pics not in focus and sharp?

Maria — Sun, 29 Dec 2013 18:20:16 GMT

I have a 24-70mm f/2.8L lens and am finding that it is not as sharp as i'd expect. I'm sure it's me and not the lens so hoping someone can help me understand what i'm doing or not doing correctly.

I'm attaching a picture as an example...hand held...here are the settings:

EF24-70mm f/2.8L II USM

59.0mm

1/640 sec; f/2.8; ISO 400

Shutter priority; Spot metering

shot with 70D

when you zoom into the tree it is cleary not in focus/sharp ;(

I've tried at differen shutter speeds but still having the same issue... going to try different apertures next...

Re: Please Help - why are pics not in focus and sharp?

Maria — Sun, 29 Dec 2013 18:18:57 GMT

and the same shot taken with my T1i - still not great but maybe a little better? also hand held...

settings:

EF24-70mm f/2.8L II USM

53.0 mm

1/640 sec; f/2.8; ISO 400

Shutter priority; Evaluative metering

Re: Please Help - why are pics not in focus and sharp?

trulandphoto — Sun, 29 Dec 2013 18:28:41 GMT

One quick thought I had was some slight haze on the front element (or filter) from bringing it out in the cold. If not that, it's probably focus or camera movemnt.

Can't really see anything in the scaled down photos.

Re: Please Help - why are pics not in focus and sharp?

Maria — Sun, 29 Dec 2013 18:59:55 GMT

how do i post so folks can enlarge to look at? i'm having the same issue indoors ;(

Re: Please Help - why are pics not in focus and sharp?

cicopo — Sun, 29 Dec 2013 19:36:11 GMT

The best idea is to post a tight crop for each sample

BUT we'll need to know what the AF locked onto PLUS at f2.8 you have a very shallow depth of field of what will be in sharp focus. Use this tool to see what I mean by filling in the boxes to see the result, and if the 70D isn't yet there just use the 60D for now.

http://www.dofmaster.com/dofjs.html

Re: Please Help - why are pics not in focus and sharp?

Maria — Sun, 29 Dec 2013 19:52:39 GMT

here are the two images cropped... AF was center... fist image is with the 70d, second with the t1i

Re: Please Help - why are pics not in focus and sharp?

Maria — Sun, 29 Dec 2013 19:53:39 GMT

I aimed the center AF at that lighter branch in the center of the first image (one taken with the 70d)

Re: Please Help - why are pics not in focus and sharp?

ScottyP — Sun, 29 Dec 2013 20:01:35 GMT

Could it just be that tree? It has a lot of different branches, so it could be hard to nail focus on the one you are aiming at, especially wide open at f/2.8 with the shallow depth of field.

Can you try it on a more solid target?

Also, you say you are spot metering, but you don't say you are selecting a single focus point. If the camera is choosing a focus point on a loose target like all those branches on that tree, you might not be getting the piece you want. Can you try it with the center AF point selected?

Re: Please Help - why are pics not in focus and sharp?

Maria — Sun, 29 Dec 2013 20:03:52 GMT

next considered a pic with text to really see what's up 😉 cropped image to post... this was taken 10feet away from the text - text is on a piece of paper that is 4x4... outside since that is the best light right now - overcast and about an hour before sun set.... shot in M, set the shutter speed an aperture, and use Auto for ISO. I usually only shoot in Tv or Av so maybe this wasn't a good test for how i use it but wanted to see what would happen...

settings:

EF24-70mm f/2.8L II USM

67.0 mm

1/200 sec; f/2.8; ISO 250

anual; Spot metering

center AF

Re: Please Help - why are pics not in focus and sharp?

Maria — Sun, 29 Dec 2013 20:17:58 GMT

I'm using the center AF.... i tend to use it 90% of the time... the text pic i just posted looks better but still thought it should be better than it is.... i found this: Jeffrey’s Autofocus Test Chart (http://regex.info/blog/photo-tech/focus-chart) so going to try it next - but not sure i fully understand what to do...

i noticed that things were a bit off with images of my daughter (which is what i shoot 90% of the time)... when i zoom in on the image her eyes (where i focused on) are not sharp... i was going to post some of those but thought the text one may be better as a start since the tree is soo busy...

when i crop the text and insert it's too small to see ;( not sure what else to do to make it visible?

Re: Please Help - why are pics not in focus and sharp?

trulandphoto — Sun, 29 Dec 2013 20:24:44 GMT

On the close up pics, the 70D shot is not in focus. It may or may not need microfocus adjusting. There are lots of resources online as to various methods for doing that.

It's nice that Canon brought that feature back into the XXD line with the 70D.

Good luck.

Re: Please Help - why are pics not in focus and sharp?

TCampbell — Sun, 29 Dec 2013 20:26:56 GMT

Hi Maria,

Whenever the focus performance of a lens is in question, you NEED to use a focus target to test the lens rather than using a real photo. There are just too many things that can go wrong with a real photo.

For example, you've used an f/2.8 f-stop... at a 10' focusing distance, the depth of field for that focal ratio is less than 1'. It would be very easy for focus to end up on the wrong object and throw the focus.

By using a focus test chart and putting the camera on a tripod, picking the middle focus point, centering that on the mid-point of the test charter, and repeatedly taking shots (I de-focus the lens after each shot to force it to re-focus and half the time I run the focus out to max distance and half the time I run the focus in to the min distance... and keep track. Sometimes a lens can have a problem focusin in one direction... but not in the other (or the margin of error will be different depending on the direction it had to turn focus.)

You can buy a commercially made test chart... but you can also download and print out your own. Just make sure you follow the directions carefully. Here's a pretty good chart you can freely download: http://regex.info/blog/photo-tech/focus-chart

Most lenses tend to provide their sharpest performance stopped down a few stops (not wide open). Typically somewhere between f/5.6 and f/8 will yeild the best performance but it varies by lens.

It is entirely possible that you have a bad copy OR that there's an issue between the focus calibration of that lens with your specific camera (in other words, a different copy of the same lens might perform differently.)

I believe the 70D also supposts auto-focus micro adjustments -- but before plunging into that, you'll want to be sure there really is an issue.

Re: Please Help - why are pics not in focus and sharp?

Maria — Sun, 29 Dec 2013 20:38:29 GMT

yes it does have micro adjustments 😉 but need to be sure of what the issue is before doing anything...

i read that test info - not sure i completely understand but will try tomorrow in good natural light...

my fear is that there is a problem with the lens - i purchased it in late September - so no way i can return or exchange now ;( with the T1i i could see that it was a little off but assumed it was me and the need for me to learn more vs the lens... but now with the 70d it is very obvious that it is way off ;(

i'm starting to feel very sick at the thought that it is the lens... if it is i think it has a 1 yr warranty so hoping that means i can have it looked at???

Re: Please Help - why are pics not in focus and sharp?

ScottyP — Sun, 29 Dec 2013 21:11:08 GMT

Does the 70d have any focus problems with other lenses? I guess it would be too much to hope for to see if someone has accidentally thumbed a bad AFMA value into your camera, and the lens is fine?

Or perhaps a modest AFMA will set things to rights?

Good luck. Keep everyone posted on your checks.

Re: Please Help - why are pics not in focus and sharp?

ebiggs1 — Mon, 30 Dec 2013 14:58:38 GMT

Maria the picture of the label is unacceptable for a 24-70mm f2.8 L lens.

But cameras and lenses only do what you tell them to.

It is imperative that neither moved during exposure. That makes the tree useless for now.

Also the DOF at f2.8 is very thin.

It is imperative to find out which of the three variables, the lens, the body or you are at fault. Until you know which, you, and/or us are blowing in the wind.

Don't go messing with any controls or adjustments on the camera. Plus make absolutely sure the camera is set to factory defaults.

Do you have, or can you go back to the store and try another lens on this body?

Do you own a tripod?

Re: Please Help - why are pics not in focus and sharp?

TCampbell — Mon, 30 Dec 2013 17:42:25 GMT

@Maria wrote:
I'm using the center AF.... i tend to use it 90% of the time... the text pic i just posted looks better but still thought it should be better than it is.... i found this: Jeffrey’s Autofocus Test Chart (http://regex.info/blog/photo-tech/focus-chart) so going to try it next - but not sure i fully understand what to do...

You'll download and print the chart on your printer. You'll place the chart so that it's leaning away from the camera at approximately a 45 degree angle (it doesn't need to be perfect... just make sure it's leaning back on a slope).

You'll put your camera on a tripod so that that there's no way it can move after focusing.

You'll select the center focus point on the camera and frame up the shot so that the center point on the camera is pointed to the middle of the focus chart ... it is crticially important that you make sure the center AF point is exactly on the bold spot in the middle of his chart and not off to a side or above or below. The center has extra strong contrast to make it easier to find.

Now you can focus the camera and take a shot.

After you've taken the shot... inspect it.

If the lens is "front focusing" (true focus distance is actually closer then your intended focus distance) then you'll notice the text toward the bottom of the chart will appear to be focused better. If the lens is "back focusing" then the top of the chart will have better focus. If the lens and camera are performing correctly... then the middle of the chart (the point you actually used to focus) will have the best focus. This is why the chart needs to lean back on an angle... so that part of the chart is closer and part of the chart is farther away.

If the lens is consistently off in the same direction, you can apply a focus adjustment for that lens in your camera. If it's randomly off then the lens will need service (and it's even better if you send in BOTH the lens AND the camera so that Canon can calibrate the lens specifically for YOUR camera.)

Re: Please Help - why are pics not in focus and sharp?

Maria — Mon, 30 Dec 2013 18:37:45 GMT

I'm going to try the test to see what happens. Depending on what I find I'm going to take the lens to the place I purchased it (Henry's) and see if they will do anything. Going to print it now...

Re: Please Help - why are pics not in focus and sharp?

Maria — Tue, 31 Dec 2013 00:05:34 GMT

i printed out that chart and took some shoots .... part i'm not clear on is how far away from the camera is chart supposed to be?

edited: just re-read the instructions - it says 10 feet! 😉 will try again....

Re: Please Help - why are pics not in focus and sharp?

Harv — Wed, 01 Jan 2014 14:47:32 GMT

Maria, that particular lens (which I have owned and used for years) is simply NOT sharp when used wide open at f/2.8 but improves when the aperture is stopped down to at least f/4. It becomes quite sharp at f/5.6 - f/8. I avoid using mine wide open. Normally this is not a problem as most of my shooting required apertures between f/5.6 and f/11.

Re: Please Help - why are pics not in focus and sharp?

Harv — Wed, 01 Jan 2014 14:49:04 GMT

P.S. I use the lens on 2 bodies..... a 1D Mark IV and a 5D Mark III. Results are the same with both bodies.