topic Re: Why are these photos blurry? in EOS DSLR & Mirrorless Cameras

Why are these photos blurry?

dtrachtman — Tue, 04 Aug 2015 13:57:21 GMT

I have a Canon Rebel T3i. I have taken a number of group photos w/tripod, w/o tripod, w/flash, w/o flash, various apertures, many on automatic mode. All on autofocus. All of them come out fuzzy, especially the people on the ends. The attached might look ok small on this web page, but if you download it and look at it 100% you will see what I mean. I have two T3i cameras and they both yield the same results. I would probably get a better photo with a phone. Any ideas?

Re: Why are these photos blurry?

RobertTheFat — Tue, 04 Aug 2015 14:40:33 GMT

A better lens might help. (That's suggested by the fact that the ends of the group are blurrier.) Given the paucity of information you've supplied (aperture, shutter speed, etc.), it's hard to come up with a more relevant suggestion.

Re: Why are these photos blurry?

dtrachtman — Tue, 04 Aug 2015 15:02:10 GMT

The lens is a Canon EF 18-135. Photos taken at shutter speeds from 1/8 to 1/250 and f3.5 - f9.0. Why does the fact that the ends are blurrier imply this is a poor quality lense? What type of lens should I buy? thanks

Re: Why are these photos blurry?

RobertTheFat — Tue, 04 Aug 2015 15:40:44 GMT

@dtrachtman wrote:
The lens is a Canon EF 18-135. Photos taken at shutter speeds from 1/8 to 1/250 and f3.5 - f9.0. Why does the fact that the ends are blurrier imply this is a poor quality lense? What type of lens should I buy? thanks

The 18-135 has a pretty good reputation, but for this purpose you'd be using it at the wide end. Lenses with a long zoom range (and yours is fairly long) tend to be sharper in the middle of their range than at the ends. The ends of your group are blurry because sharpness falls off as the subject gets farther from the center of the lens. More expensive lenses tend to do a better job of minimizing that effect. 1/8 of a second will usually work if you're using a tripod, but it's too slow for this kind of picture, because the subjects will move around. I wouldn't use anything slower than 1/160 for group pictures, the only exception being when a flash is providing most of the light. For group pictures I normally use the Canon 17-55mm f/2.8 IS on a 7D body. That lens is very good and cheaper than it used to be. Whether that lens would solve your problem, I don't know. Maybe you could rent or borrow one and try it. Note that although you'd still be using it at the wide end, it doesn't have to worry about being sharp at 135 mm.

Re: Why are these photos blurry?

TCampbell — Tue, 04 Aug 2015 16:06:36 GMT

The lens appears to be front-focused... as I inspect the carpeting the focus appears to improve as we get closer to the camera.

How did you focus?

Was this via the viewfinder? Liveview? If viewfinder, how did you select the AF point (or did you let the camera select the point)?

Re: Why are these photos blurry?

dtrachtman — Tue, 04 Aug 2015 17:56:00 GMT

I'll try it. thanks!

Re: Why are these photos blurry?

dtrachtman — Tue, 04 Aug 2015 17:56:46 GMT

I use auto-focus, no liveview. I let the camera select but make sure it is focused in the middle.

Re: Why are these photos blurry?

TCampbell — Tue, 04 Aug 2015 18:58:50 GMT

@RobertTheFat wrote:
@dtrachtman wrote:
The lens is a Canon EF 18-135. Photos taken at shutter speeds from 1/8 to 1/250 and f3.5 - f9.0. Why does the fact that the ends are blurrier imply this is a poor quality lense? What type of lens should I buy? thanks
The 18-135 has a pretty good reputation, but for this purpose you'd be using it at the wide end. Lenses with a long zoom range (and yours is fairly long) tend to be sharper in the middle of their range than at the ends. The ends of your group are blurry because sharpness falls off as the subject gets farther from the center of the lens. More expensive lenses tend to do a better job of minimizing that effect. 1/8 of a second will usually work if you're using a tripod, but it's too slow for this kind of picture, because the subjects will move around. I wouldn't use anything slower than 1/160 for group pictures, the only exception being when a flash is providing most of the light. For group pictures I normally use the Canon 17-55mm f/2.8 IS on a 7D body. That lens is very good and cheaper than it used to be. Whether that lens would solve your problem, I don't know. Maybe you could rent or borrow one and try it. Note that although you'd still be using it at the wide end, it doesn't have to worry about being sharp at 135 mm.

I'm studying the image carefully at 100% size and while your points are true, I don't think they apply to this particular image.

The image posted has a shutter speed of 1/60th sec at f/4. As I study it carefully, there are no signs of blur caused by motion (which will generally show a directional blur) so I do not think the shutter speed is too slow. This was taken at 18mm. It would typically be possible for a person to hand-hold that shot at 1/30th sec even without an image stabilizing lens.

Also, the subject at the very center of the lens axis is out of focus. This image simply looks like the camera did not focus correctly. If the camera was in AI Servo focus mode then another possibility is that the photographer pressed the shutter button to take the shot before the camera had finished focusing ("AI Servo" mode will take the shot when the shutter button is fully pressed regardless of whether or not it had time to focus -- it will not wait to confirm focus in that mode. It will only wait for a focus lock in "One Shot" mode. These behaviors are known as "Release Priority" (in "AI Servo" mode) vs. "Focus Priority" (in "One Shot" mode.))

What I notice more than anything is that the carpet texture on the floor... it's blurred under the subject's feet. But inspect this carpet texture as you get nearer to the camera and you see it coming into focus. This tells me that the camera was focused for a much closer distance. The lens was not focused at the subject distance. The next question is why wasn't the lens focused at the subject distance, and to answer that, we'd need more information.

Re: Why are these photos blurry?

TCampbell — Tue, 04 Aug 2015 19:03:50 GMT

@dtrachtman wrote:
I use auto-focus, no liveview. I let the camera select but make sure it is focused in the middle.

If you press the focus point selection button (upper right corner on the back of your camera) you can then use the main dial (wheel in front of camera - next to the shutter button) to select a specific AF point that you'd like to use. The choices cycle through each point (it will illuminate as you scroll) and then all points illuiminate (meaning the camera can auto-select the point).

If you allow the camera to auto-select, it will select the AF point which is able to achieve focus at the closest possible distance to the lens.

What this means to an image like this is that the lower middle point will lock on the carpet INSTEAD of using a point over a subject in the group. This would cause the camera to miss focus (technically it nailed focus on what it was programmed to select.)

If you can can upload an image which was taken directly from your camera and not touched by any other program (don't open it in Photoshop, etc.) then we can see more image meta-data including the select AF point (Canon records that in the meta-data file but I see that your image posted above has that data stripped out because the image was processed by Photoshop and Photoshop doesn't support focus point meta-data.)

Re: Why are these photos blurry?

RobertTheFat — Tue, 04 Aug 2015 19:34:05 GMT

@TCampbell wrote:
@RobertTheFat wrote:

The 18-135 has a pretty good reputation, but for this purpose you'd be using it at the wide end. Lenses with a long zoom range (and yours is fairly long) tend to be sharper in the middle of their range than at the ends. The ends of your group are blurry because sharpness falls off as the subject gets farther from the center of the lens. More expensive lenses tend to do a better job of minimizing that effect. 1/8 of a second will usually work if you're using a tripod, but it's too slow for this kind of picture, because the subjects will move around. I wouldn't use anything slower than 1/160 for group pictures, the only exception being when a flash is providing most of the light. For group pictures I normally use the Canon 17-55mm f/2.8 IS on a 7D body. That lens is very good and cheaper than it used to be. Whether that lens would solve your problem, I don't know. Maybe you could rent or borrow one and try it. Note that although you'd still be using it at the wide end, it doesn't have to worry about being sharp at 135 mm.
I'm studying the image carefully at 100% size and while your points are true, I don't think they apply to this particular image. ,,,

Yes, I was just answering the OP's questions, not trying to analyze the picture.

Re: Why are these photos blurry?

TCampbell — Tue, 04 Aug 2015 19:53:43 GMT

If you can get the image straight out of the camera (unaltered by any other program) you can open the image in Canon Digital Photo Professional. Right click the image and this opens a pop-up menu. Select "AF Point" and this will turn on an overlay indicating which AF points were used to focus the image.

I normal force my cameras to use a specific AF point (or sometimes a zone as the pro bodies with more AF point can do) but here's an example taken with my 5D II a few years back which has the same 9 point AF system. This camera was allowed to auto-select the AF point, and here's a screen-capture of the DPP window to show you what it displays:

The black squares represent the positions of the AF points, but the squares shown in RED indicate which points the camera actually used when locking focus.

The camera will evaluate all available AF points to determine if it can lock focus with them and, of those, it will select the AF point that can lock focus using the closest focusing distance. In this particular example, the closest point would have been located near the "knee" of the lady seated at lower left. But instead it selected points near her chest and hip which it evaluated to be "about the same". The selection of the focus point isn't necessarily 100% reliable (but you do see these points blink in the viewfinder). To get more reliable focus point selection, force the camera to use the point you want to use for focus.

Note that it is possible to lock focus, then recompose the camera framing -- which would mean that the AF point used to lock focus is no longer in front of the subject used when locking focus (because the photographer recomposed the shot after locking focus.) So if you use the "focus and recompose" technique then displaying the AF points wouldn't be a reliable way to identify what the camera used to lock focus.

Re: Why are these photos blurry?

amfoto1 — Tue, 04 Aug 2015 20:39:50 GMT

Opanda EXIF software tells me that your sample shot was done with T3i and 18-135mm II lens at ISO 400, 1/60 shutter speed, f4 aperture with the lens zoomed to its widest 18mm and the camera doing all the exposure settings in Program mode. Also, the flash fired.

All the recommendations about focusing technique are well and good. I'd also use a single AF point, manually selected. Probably the center one. Also I'd use One Shot as the most accurate of the viewfinder-based AF focusing modes. Alternatively, Live View focus could have been used, which is slower but can be even more accurate. It also can help with manual focus, if you do that instead, because you can magnify the Live View image up to 10X on most cameras that have it.

In this case, I'd take several shots, refocusing each one. The reason is the lighting, which appears to be common fluorescent, which is notorious for "messing with" focus and metering accuracy. The reason is that fluorescent lamps cycle on and off at a high rate... 120 Hz in the US, 100 Hz in some othre parts of the world. This is so fast the human eye doesn't notice. But our cameras can and do see it... and can be fooled by it.

However I think the main problem is that your are using an f4 aperture. Lenses are typically not at their best and sharpest at or very near their largest aperture. Stop down to f5.6 or f8 and I think you'll see a lot of improvement. To do so, you'll have to get out of Program mode and use Av or aperture value exposure mode instead. This still gives you the same auto exposure and flash performance, but will allow you to select the aperture, after which the camera will automatically set the appropriate shutter speed. You may need to set a higher ISO to get adequate shutter speed.

Stopping the lens down also would give you more depth of field to work with. That can be very important because another concern is "field curvature". When your subjects are in a straight line and you focus on the one in the very middle, chances are that natural lens field curvature effects toward the edges will cause subjects there to be softer. This is more pronounced the wider angle the lens is... Ideally you would instead line up the people in a slight arc, where the ones on either end are a little closer to you. However, you'd be guessing or basing your posing on experience... because it's hard to see in the viewfinder. An easier solution is stopping down to increase depth of field, which will to some extend offset the field curvature problem.

Using a wide angle lens present other possible problems, though. One is that there is inevitable optical distortions with wide lenses, one of which causes subjects nearer the edges to be exaggerated and look larger than they are. You can see some of this occuring in the ceiling light panels (which also show "perspective" distortion). But I'd also bet that the ladies at either end of the row don't have that large an arm, as the one nearest the edge of the image appears in the photo. This is called "anamorphic" distortion and is an optical effect that's unavoidable with wide angle lenses. It's one reason most portraiture is done with standard to short telephotos, instead. The best solution is to back up farther and zoom to the 30mm or 50mm range... i.e. to avoid using wide angles for group shots like this. But to do so will require adequate working space and a stronger flash.

Which brings us to yet another consideration.... when shooting a Canon camera and flash in any of the auto-exposure modes, the camera will set exposure according to the ambient light, and then the flash will be fired as FILL.... about 1-2/3 stops underexposure automatically. If you want the flash to be the main or primary light source, you need to set the camera to M or Manual mode. So long as the flash is set to ETTL, the camera then will ignore ambient light for exposure calculations and will fire the flash as strongly as needed for illumination... In other words, you still get auto-exposure even though the camera is set to M. However, now it is being done with FULL flash.

Only problem is, if you are using the camera's builit in flash, it may not have enough power for this wide a shot at this distance. Built-in flashes are notoriously wimpy. If using an external 430EX or 580EX or similar flash, you would have ample light for the purpose, as well as better/more even wide angle coverage (using the flash's built in wide angle diffusion panel.)

***********

Alan Myers
San Jose, Calif., USA
"Walk softly and carry a big lens."
GEAR: 5DII, 7D(x2), 50D(x3), some other cameras, various lenses & accessories
FLICKR & EXPOSUREMANAGER

Re: Why are these photos blurry?

dtrachtman — Tue, 04 Aug 2015 20:28:36 GMT

Good point, but I thought I always try to make sure the red dots focus on people in the middle of the group. This website won't let me upload the images because they are too big, but you can download them here:

https://www.dropbox.com/s/748wz6oas03m3wh/IMG_1991.JPG?dl=0

https://www.dropbox.com/s/4xn6eejsq6dhdjq/IMG_1994.JPG?dl=0

I have taken dozens of group shots and they all turn out like this. I guess it's possible that it always focused wrong.

Re: Why are these photos blurry?

dtrachtman — Wed, 05 Aug 2015 13:40:26 GMT

Thanks for all this great feedback. My last reply was before I saw all of this. I have tried different apertures and always got the same result. I bought a more powerful flash and the Tokina 11-16 lens and hopefully between these things it will also improve. I will also always force a specific focus location like you all suggested. thanks again

Re: Why are these photos blurry?

RobertTheFat — Wed, 05 Aug 2015 14:59:36 GMT

@dtrachtman wrote:
Thanks for all this great feedback. My last reply was before I saw all of this. I have tried different apertures and always got the same result. I bought a more powerful flash and the Tokina 11-16 lens and hopefully between these things it will also improve. I will also always force a specific focus location like you all suggested. thanks again

You could have a problem with the Tokina, because it's too wide for most flashes. You might get acceptable results with bounce flash and a diffuser, but I've always regarded my 11-16 as pretty much an outdoor lens only.

Re: Why are these photos blurry?

dtrachtman — Wed, 05 Aug 2015 16:51:01 GMT

Wow, that would have never occurred to me. All these group shots that I am asked to take are inside. Ok, I will experiment and see what happens.

Re: Why are these photos blurry?

TCampbell — Wed, 05 Aug 2015 17:35:26 GMT

Big groups typically need more than one flash and typically you want the flash to be softened.

That means you almost want:

Two (or more) flashes (preferably radio controlled such as the Canon Speedlite 600EX-RT, but you can use third party flash and buy a trigger and a receivers.)
A trigger. If using Canon, you can use the Canon ST-E3-RT on-camera trigger (that's a radio trigger that can control either the 600EX-RT flashes or the 430EX III-RT flashes -- that trigger ONLY does radio so it cannot control non-radio flashes.)
A couple of light stands
A couple of soft-boxes. I have the Lastolite EzyBox Speedlite version. Whereas many soft-boxes require putting the flash inside the softbox, these softboxes are designed to be mobile (easy to setup and take down quickly) but the flash mounts on a bracket behind the softbox and the head of the flash is positioned through a whole in the back. Westcott makes something called the "RapidBox" which is a similr idea (possibly better -- I haven't tried theirs) but again... flash is on a bracket behind the softbox and fires into the softbox through a hole in the back. Westcott's version has an optional beauty-dish-like attachment so the flash fires into a round shiny disk which bounces light outward into the sides of the softbox -- which then reflects forward toward your subjects. The Lastolite box doesn't have this so you can get a bit of a "hot spot" in the soft box. They have an extra diffusion panel that can go on the inside of the box to soften the hot-spot but each diffusion panel eats a bit of light.

If you need extra light, it is possible to mount multiple flashes on a single stand (like the Westcott "Triple Threat" speedlite bracket) and they all fire synchronously -- boosting the light output and speeding the recycle times.

Re: Why are these photos blurry?

RobertTheFat — Wed, 05 Aug 2015 19:03:24 GMT

@TCampbell wrote:
Big groups typically need more than one flash and typically you want the flash to be softened.

That means you almost want:

Two (or more) flashes (preferably radio controlled such as the Canon Speedlite 600EX-RT, but you can use third party flash and buy a trigger and a receivers.)
A trigger. If using Canon, you can use the Canon ST-E3-RT on-camera trigger (that's a radio trigger that can control either the 600EX-RT flashes or the 430EX III-RT flashes -- that trigger ONLY does radio so it cannot control non-radio flashes.)
A couple of light stands
A couple of soft-boxes. I have the Lastolite EzyBox Speedlite version. Whereas many soft-boxes require putting the flash inside the softbox, these softboxes are designed to be mobile (easy to setup and take down quickly) but the flash mounts on a bracket behind the softbox and the head of the flash is positioned through a whole in the back. Westcott makes something called the "RapidBox" which is a similr idea (possibly better -- I haven't tried theirs) but again... flash is on a bracket behind the softbox and fires into the softbox through a hole in the back. Westcott's version has an optional beauty-dish-like attachment so the flash fires into a round shiny disk which bounces light outward into the sides of the softbox -- which then reflects forward toward your subjects. The Lastolite box doesn't have this so you can get a bit of a "hot spot" in the soft box. They have an extra diffusion panel that can go on the inside of the box to soften the hot-spot but each diffusion panel eats a bit of light.
If you need extra light, it is possible to mount multiple flashes on a single stand (like the Westcott "Triple Threat" speedlite bracket) and they all fire synchronously -- boosting the light output and speeding the recycle times.

<guffaw!> If I tried to set up equipment like that to capture the participants after a City Council Inauguration or Outstanding Employee Awards ceremony, I'd be laughed right out of the hall. Group photographs are already enough like herding cats, even under the best of circumstances.

Re: Why are these photos blurry?

TCampbell — Wed, 05 Aug 2015 19:28:10 GMT

@RobertTheFat wrote:

<guffaw!> If I tried to set up equipment like that to capture the participants after a City Council Inauguration or Outstanding Employee Awards ceremony, I'd be laughed right out of the hall. Group photographs are already enough like herding cats, even under the best of circumstances.

I'm guessing you are probably not familiar with the EzyBox. It's specifically designed to be a highly portable softbox (not as bulky to setup as a regular softbox). They're often mounted on a monopod isntead of a light stand and held by a human assistant specifically to be mobile (intended for location shoots - not for studio use.)

But... If the "point" of the gathering is to get the photo (and it sounds like it is) then having supplemental lighting would be no big deal.

All my large group shots at weddings were done with a live human holding the "side light" (no light stands) because the live persons is infinitely more mobile and they know where to hold and point the light. But... I've seen photographers who don't have an assistant setup light stands. At a wedding, I don't like the delay of having to set them up and take them down (it's not that much of a delay... but considering the number of times the bride & groom will have their photo taken on that particular day, I try to minimize the amount of time involved.)

But this sounds different. It sounds like these people are coming together SPECIFICALLY to get a group photo.

Bob, just because YOU haven't used a setup like this, doesn't mean others have not used it successfully and... staring a response with "<guffaw!>" as if you think this is a joke -- which makes me question your professionalism and your experience.

Re: Why are these photos blurry?

RobertTheFat — Wed, 05 Aug 2015 20:28:13 GMT

@TCampbell wrote:
@RobertTheFat wrote:
<guffaw!> If I tried to set up equipment like that to capture the participants after a City Council Inauguration or Outstanding Employee Awards ceremony, I'd be laughed right out of the hall. Group photographs are already enough like herding cats, even under the best of circumstances.
I'm guessing you are probably not familiar with the EzyBox. It's specifically designed to be a highly portable softbox (not as bulky to setup as a regular softbox). They're often mounted on a monopod isntead of a light stand and held by a human assistant specifically to be mobile (intended for location shoots - not for studio use.)

But... If the "point" of the gathering is to get the photo (and it sounds like it is) then having supplemental lighting would be no big deal.

All my large group shots at weddings were done with a live human holding the "side light" (no light stands) because the live persons is infinitely more mobile and they know where to hold and point the light. But... I've seen photographers who don't have an assistant setup light stands. At a wedding, I don't like the delay of having to set them up and take them down (it's not that much of a delay... but considering the number of times the bride & groom will have their photo taken on that particular day, I try to minimize the amount of time involved.)

But this sounds different. It sounds like these people are coming together SPECIFICALLY to get a group photo.

Bob, just because YOU haven't used a setup like this, doesn't mean others have not used it successfully and... staring a response with "<guffaw!>" as if you think this is a joke -- which makes me question your professionalism and your experience.

Cut it out, Tim. I wasn't ridiculing your response; I was just laughing at the uncertainty of its applicability to the situations I face. Surely you must realize the respect in which your detailed and well thought out responses are held by the members of this forum. Most of us have written comments to that effect from time to time; and if you write a book, we'll all buy it.

Possibly the OP has the luxury of a dedicated occasion for group pictures, but I rarely do. Mine are almost always at the end of a ceremonial occasion that I've already photographed, with the participants milling around with their families or co-workers and/or itching to flee the scene. Anything that interferes with the process of getting them on the podium together and reeling off as many shots as they'lll stand still for, is a non-starter.