90 votes
Accepted

How did photography work before auto-focus was invented?

Through-the-lens focusing cameras had focusing screens — usually ground glass or fresnel lens (related: What is a focusing screen?). View cameras (the old-style large cameras with bellows) projected ...
scottbb's user avatar
  • 32.7k
52 votes

Why aren't faces sharp in my f/1.8 portraits even though I'm carefully using center-point autofocus?

You're not doing anything wrong. You're just finding the limits of the camera/lens combination you are using. The EF 50mm f/1.8 (in various versions) has been known as the "plastic fantastic" for a ...
Michael C's user avatar
  • 175k
30 votes
Accepted

Do all Canon DSLRs have in-body AF motors?

No Canon EOS body needs AF motors because every single Canon EF lens released since the EOS system was introduced since 1987 has a focus motor in the lens. Thus no Canon EOS camera has ever had a need ...
Michael C's user avatar
  • 175k
28 votes
Accepted

Why do even high-end cameras often still include normal (non-cross-type) AF sensors?

In actuality, a cross type AF sensor is just two "normal" AF sensors, one with the lines oriented in a vertical direction and the other with the lines oriented in a horizontal direction, that are ...
Michael C's user avatar
  • 175k
27 votes

How did photography work before auto-focus was invented?

How did photography work before auto-focus was invented? Pretty well for those willing to learn how to do it with the tools we had at at the time. The same is true now. The only difference is that ...
Michael C's user avatar
  • 175k
21 votes
Accepted

Do I need to turn off camera before switching auto-focus on/off?

According to it, we should first turn off the camera before turning auto-focus on/off. That's quite cumbersome obviously. That seems pretty ridiculous. Perhaps the authors are serious about their ...
Caleb's user avatar
  • 31.7k
21 votes

What happened? Sold my Canon EOS 5D Mark II and buyer says images are not in focus

I can not imagine damage that would impact focusing without visible damage to the packaging or the camera. These things are pretty sturdy. you would have to damage the mirror or shutter box to really ...
cmason's user avatar
  • 14.8k
21 votes
Accepted

How do I diagnose the source of blurry photos?

The question is extremely broad. There are a lot of questions and answers here that address particular aspects of blurry pictures. Putting all of that in one answer would be excessively long as well ...
Michael C's user avatar
  • 175k
19 votes
Accepted

Focus point causing unsharp images?

I don't think you're lacking in sharpness: at full size, the image you post shows sharp eyelashes and teeth. If you are using a large aperture (<F2), that explains the unsharp ears. When you ...
remco's user avatar
  • 3,161
17 votes
Accepted

Are there entry-level DSLRs with built in autofocus motors?

There are three parts to the answer to this, which is appropriate, because with Sony, Olympus, Panasonic, Fujifilm, and Sigma focusing on mirrorless designs, there are really only three companies ...
mattdm's user avatar
  • 143k
16 votes

Do all Canon DSLRs have in-body AF motors?

No Canon EOS camera has an in-body focus motor. Canon's lens mount is 100% electric, there is no mechanical linkage. (Some mounts e.g. Pentax have a mechanical link for the aperture too, for some ...
crunch's user avatar
  • 996
16 votes
Accepted

How to take sharper photos

The first image was shot wide open with what is essentially the lowest cost Canon lens (50mm f/1.8), in demanding low light conditions, and at ISO 1600. I'd say your results are exactly what I would ...
dpollitt's user avatar
  • 46.5k
15 votes
Accepted

How sharp are RAW photos before processing?

Are RAW images by nature slightly blurry prior to processing? If I open them up in Lightroom and zoom into the photo, my photos are not tack sharp but a bit blurry. Once I process, it comes out ...
mattdm's user avatar
  • 143k
14 votes

Do I need to turn off camera before switching auto-focus on/off?

The warning you read applies to Live View shooting. If you look at the T5I manual it states on page 156 under the Continuous AF section , "...During Continuous AF, turn off the power before you set ...
rob j crowe's user avatar
  • 1,401
13 votes

Why aren't faces sharp in my f/1.8 portraits even though I'm carefully using center-point autofocus?

It might be best if you post an example image, but in any case, there are a few things to bear in mind. First, shooting at such wide aperture provides very little leeway between the near and far ...
cmason's user avatar
  • 14.8k
12 votes

How did photography work before auto-focus was invented?

There are diferent topics here. 1) A toy camera, and some new cameras, for example survilance cameras, some phone cameras do not need to focus because its focus range is very extense. Normally this ...
Rafael's user avatar
  • 24.8k
12 votes

Focus point causing unsharp images?

Looking at the example image at full magnification, it seems that the sharpest part of the boy's face is the tip of his nose. If you look at his left hand (camera right), you see that the area from ...
Michael C's user avatar
  • 175k
12 votes

Why won't a Tamron AF LD 200-400mm f5.6 model 75DN autofocus on Nikon D3300?

The D7100 body that this lens works with has a focus motor built into the body that connects to a mechanical coupling on Nikkor AF lenses and third party equivalents to move the focus elements in the ...
Michael C's user avatar
  • 175k
11 votes
Accepted

Why does holding the focus and recomposing also affect the brightness of my photo?

It sound like your camera is locking the exposure in addition to the focus when you perform a half shutter press. This would explain the overexposure when moving from a dark river to the bright sky: ...
tittaenälg's user avatar
11 votes
Accepted

Will I not be able to AF with a 2× teleconverter?

You will have to manually focus by moving the focusing ring on the lens. Using the center focus point to focus and then recompose is still considered autofocus. Even if you have manually selected ...
Michael C's user avatar
  • 175k
10 votes

What is Nano USM and how does it compare to an STM or USM lens?

Canon autofocus lenses have long focused on speed and not so much on smooth and quiet operation. This is what we know today as USM (Ultrasonic motor). As usage of DSLRs for video became more popular, ...
dpollitt's user avatar
  • 46.5k
9 votes
Accepted

Autofocus points in Mirrorless Cameras

As with many things, the marketers have tried to convince us that bigger, more, or higher priced is always "better". Most of the time in photography quality trumps quantity. Regardless of how many ...
Michael C's user avatar
  • 175k
9 votes

Is there any reason you would use one-shot focus over AI-Servo?

Yes it is convenient, and does track a subject, but not always your subject. For this reason, I always use one-shot. In situations where there are multiple potential subjects, but one I wish to ...
cmason's user avatar
  • 14.8k
9 votes

How did photography work before auto-focus was invented?

To suppliment the answers on focusing aids in SLR cameras meant to be manually focused, let me give you a link to hyperfocal distance which is used in fixed focus cameras. My parents’ (later handed ...
JDługosz's user avatar
  • 4,382
9 votes

How did photography work before auto-focus was invented?

The current answers explore manual through-the-lens focussing and fixed focus cameras, and do a good job of explaining them, but they miss another approach - distance estimation. For example, my old ...
Oddthinking's user avatar
  • 1,141
9 votes
Accepted

What is the red grid pattern appearing in the video?

That is an auto-focus assist light shone by another photo camera that is left from the video camera. This link explains how this light works on Nikon DSLR cameras. As far as I know it is similar to ...
Saaru Lindestøkke's user avatar
9 votes
Accepted

Why does my "ultrasonic" lens have trouble focusing in low-light and low-contrast scenes?

"Ultrasonic" (or "USM") has nothing to do with active vs. passive autofocus. It's a type of drive motor for actually moving the focus elements, in contrast to e.g. stepper motors ("STM"). Contrast ...
twalberg's user avatar
  • 5,138
9 votes
Accepted

Macro photo that I cannot repeat

Assumptions I think this is a combination of using digital zoom (or cropping) and flash. I don't own an iPhone SE but a Samsung S8. On a high level they have comparable cameras though. iPhone SE ...
Saaru Lindestøkke's user avatar
8 votes

Why won't my Fujifilm X-E3 focus or take photos?

Notice that the aperture is listed as "F 0". I bet the lens isn't attached right — try removing it and putting it back.
mattdm's user avatar
  • 143k
8 votes

Why does my lens only autofocus when I have a teleconverter attached?

The electronics guy in me would put some money on some bad contact somewhere on the lens, that the Kenko converter mount exercises a bit differently from the camera one. Some contact cleaning fluid ...
xenoid's user avatar
  • 21.3k

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