Helping Determine the Correct Focal Length for Photography & Videography
Here at Lensrentals.com, we get asked a common question on the daily, which is something to the regards of “I’m shooting X, what do you think the best focal length(s) would be?” By definition, this is an impossible question to answer completely and would need a multitude of variables before we could actually give a recommendation. But at the very least, we thought to ourselves, “Certainly, we could give people a visual representation, right?”
And so, that is where we’re at now. Before we get too far into this demonstration, it’s worth addressing the variables mentioned above. The first one is going to come down to your sensor size. For this test, all of our examples were done with a full-frame 35mm sensor size. If you’re using a crop sensor, your effective focal length might change, so I’ve included a small table showing you what you would be multiplying your focal length by to get a visual result.
| Sensor Size | Focal Length Multiplier (Crop Factor) |
|---|---|
| 1/2.5" | 6.0 |
| 1" | 2.7 |
| 4/3" / Four Thirds | 1.84–2 |
| APS-C | 1.5-1.6 |
| 35mm full frame | 1.0 |
| Crop Sensor Medium format | 0.79 |
| Medium format | 0.64 |
The second primary variable would be distance and how it relates to the depth of field and image compression. That talking point is worthy of another article itself (and has been covered several times already), so instead, we’re going to touch on the depth of field. If you’re shooting with particular settings, I recommend this handy calculator to help determine your depth of field. While there is a mathematical equation that can be memorized, it’s sometimes easier to use the calculator in your pocket.
For our test, we decided to head over to Mud Island Amphitheater in beautiful Memphis, TN. With us, was an eclectic lineup of various focal lengths, and our lovely model for the day, who I’ve decided to call Beatrice. We then set up six different shooting lengths, 10 feet, 20 feet, 50 feet, 100 feet, 150 feet, and 200 feet, and shot a series of images with Beatrice in the frame.
10 Feet Distance
At 10 feet, we shot a series of focal lengths that would be common within this shooting distance. In general, 10 feet would be considered a pretty typical distance from your subject when shooting a portrait session with one to two subjects. Our results of 16mm-200mm are posted below.
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16mm Focal Length
24mm Focal Length
35mm Focal Length
50mm Focal Length
70mm Focal Length
100mm Focal Length
150mm Focal Length
200mm Focal Length
20 Feet Distance
From there, we doubled our distance from our subject and extended our testing to 16mm – 800mm (We were unable to do so on the 10-foot test, because of minimum focusing distance limitations).
#gallery-2 { margin: auto; } #gallery-2 .gallery-item { float: left; margin-top: 10px; text-align: center; width: 33%; } #gallery-2 img { border: 2px solid #cfcfcf; } #gallery-2 .gallery-caption { margin-left: 0; } /* see gallery_shortcode() in wp-includes/media.php */
16mm Focal Length
24mm Focal Length
35mm Focal Length
50mm Focal Length
70mm Focal Length
100mm Focal Length
150mm Focal Length
200mm Focal Length
300mm Focal Length
400mm Focal Length
500mm Focal Length
600mm Focal Length
700mm Focal Length
800mm Focal Length
50 Feet Distance
You know the routine by now. The following photos were shot at 50 feet from the subject.
#gallery-3 { margin: auto; } #gallery-3 .gallery-item { float: left; margin-top: 10px; text-align: center; width: 33%; } #gallery-3 img { border: 2px solid #cfcfcf; } #gallery-3 .gallery-caption { margin-left: 0; } /* see gallery_shortcode() in wp-includes/media.php */
16mm Focal Length
24mm Focal Length
35mm Focal Length
50mm Focal Length
70mm Focal Length
100mm Focal Length
150mm Focal Length
200mm Focal Length
300mm Focal Length
400mm Focal Length
500mm Focal Length
600mm Focal Length
700mm Focal Length
800mm Focal Length
100 Feet Distance
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16mm Focal Length
24mm Focal Length
35mm Focal Length
50mm Focal Length
70mm Focal Length
100mm Focal Length
150mm Focal Length
200mm Focal Length
300mm Focal Length
400mm Focal Length
500mm Focal Length
600mm Focal Length
700mm Focal Length
800mm Focal Length
150 Feet Distance
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16mm Focal Length
24mm Focal Length
35mm Focal Length
50mm Focal Length
70mm Focal Length
100mm Focal Length
150mm Focal Length
200mm Focal Length
300mm Focal Length
400mm Focal Length
500mm Focal Length
600mm Focal Length
700mm Focal Length
800mm Focal Length
1120mm Focal Length
1600mm Focal Length
200 Feet Distance
#gallery-6 { margin: auto; } #gallery-6 .gallery-item { float: left; margin-top: 10px; text-align: center; width: 25%; } #gallery-6 img { border: 2px solid #cfcfcf; } #gallery-6 .gallery-caption { margin-left: 0; } /* see gallery_shortcode() in wp-includes/media.php */
16mm Focal Length
24mm Focal Length
35mm Focal Length
50mm Focal Length
70mm Focal Length
100mm Focal Length
150mm Focal Length
200mm Focal Length
300mm Focal Length
400mm Focal Length
500mm Focal Length
600mm Focal Length
700mm Focal Length
800mm Focal Length
1120mm Focal Length
1600mm Focal Length
Hopefully, this quick piece has given you a better representation of what each focal length looks at different distances. For ease of use, we’ve also put together this handy PDF available for download, which highlights all of the information in this article. And if you’re looking to do your own experiments with focal lengths, be sure to check out our broad range of telephoto lenses.
33 Comments
J.L. Williams ·
This is a useful visual reference, but it doesn’t answer the question I usually have, which is: “I’ve got Lens X; how far away do I need to be to shoot A?” or conversely, “I want to shoot A from a distance of B; what lens do I need?”
Fortunately, I’ve learned to work this out by taking advantage of the fact that lens-to-sensor and distance-to-subject are “similar triangles” — their proportions are always the same. So as long as you know your actual sensor size (no phony “crop factor” needed) you can usually work out the dimensions in your head with a little judicious rounding.
Example: “My sensor is 24mm wide and I’ve got a 50mm lens; how far away do I need to be to cover a 9-foot-wide seamless paper?” Well, your lens’ focal length is about 2x your sensor width, so your subject distance will be proportional — about 18 feet away from your 9-foot-wide background.
Or going the other way: “My sensor is 19mm high and my seat is about 100 feet away from the theater stage; what lens do I need to cover an 10-foot-high space so I can see the performers plus a little scenery?” Well, your distance is 10 times your desired field height, so to fill your 19mm sensor you need about 190mm… a 180 or 200 should work fine. All simple arithmetic.
DrJon ·
If you go to the tawbaware site they have a lot of calculators, including one giving the physical size of the image at a particular distance. You can quickly iterate this to an answer.
50mm lens, 1.5 crop sensor, 9 feet wide image -> 18.75 feet
J.L. Williams ·
This is a useful visual reference, but it doesn't answer the question I usually have, which is: “I've got Lens X; how far away do I need to be to shoot A?” or conversely, “I want to shoot A from a distance of B; what lens do I need?”
Fortunately, I've learned to work this out by taking advantage of the fact that lens-to-sensor and distance-to-subject are “similar triangles” — their proportions are always the same. So as long as you know your actual sensor size (no phony “crop factor” needed) you can usually work out the dimensions in your head with a little judicious rounding.
Example: “My sensor is 24mm wide and I've got a 50mm lens; how far away do I need to be to cover a 9-foot-wide seamless paper?” Well, your lens' focal length is about 2x your sensor width, so your subject distance will be proportional — about 18 feet away from your 9-foot-wide background.
Or going the other way: “My sensor is 19mm high and my seat is about 100 feet away from the theater stage; what lens do I need to cover an 10-foot-high space so I can see the performers plus a little scenery?” Well, your distance is 10 times your desired field height, so to fill your 19mm sensor you need about 190mm... a 180 or 200 should work fine. All simple arithmetic.
DrJon ·
If you go to the tawbaware site they have a lot of calculators, including one giving the physical size of the image at a particular distance. You can quickly iterate this to an answer.
50mm lens, 1.5 crop sensor, 9 feet wide image -> 18.75 feet
grubernd ·
nice presentation.
but starting for a portrait at 304,8cm distance is a nogo in my book. you should use a distance related to the intimacy you want to create – the distance you would have to the person in a real interaction – and then pick the lens for the framing you want to achieve.
portraits happen between 75 and 220cm distance.
beyond that it’s always more like a fashion picture.
grubernd ·
nice presentation.
but starting for a portrait at 304,8cm distance is a nogo in my book. you should use a distance related to the intimacy you want to create - the distance you would have to the person in a real interaction - and then pick the lens for the framing you want to achieve.
portraits happen between 75 and 220cm distance.
beyond that it's always more like a fashion picture.
Stanislaw Zolczynski ·
In film making there`s another situation where you choose focal lenght in relation to framed scene. Spacial relation between two people, a normal conversation distance which miight be face up to across the table, filmed from some 45 degrees. Use too longfocal and the heads seem to be pasted on, use too wide and it introduces a domination of foreground person.
Stanislaw Zolczynski ·
In film making there`s another situation where you choose focal lenght in relation to framed scene. Spacial relation between two people, a normal conversation distance which miight be face up to across the table, filmed from some 45 degrees. Use too longfocal and the heads seem to be pasted on, use too wide and it introduces a domination of foreground person.
GulliNL ·
While this is all very helpful, I keep on being distracted by the model. She doesn’t seem to be… there. You know what I mean? It’s like she is just standing there and not really enjoying herself. It might be ofcourse that doing so many shots with so many lenses tends to get a bit boring.
So I think there is a lesson to be learned here; no matter how awesome you are in framing your subject and having the lighting in shape and everything, you have to build rapport with your model. Otherwise all your work will be for nothing.
Baconator ·
She seems stoned.
SmithW6079 ·
Given what passes for a model these days I was struck by how natural she looks. Less plastic than some of those Kardashians, in my opinion.
Michael Clark ·
Maybe she’s concentrating very hard to keep from falling off that funny looking skateboard she’s standing on in high heels?
GulliNL ·
While this is all very helpful, I keep on being distracted by the model. She doesn't seem to be... there. You know what I mean? It's like she is just standing there and not really enjoying herself. It might be ofcourse that doing so many shots with so many lenses tends to get a bit boring.
So I think there is a lesson to be learned here; no matter how awesome you are in framing your subject and having the lighting in shape and everything, you have to build rapport with your model. Otherwise all your work will be for nothing.
Baconator ·
She seems stoned.
SmithW6079 ·
Given what passes for a model these days I was struck by how natural she looks. Less plastic than some of those Kardashians, in my opinion.
Michael Clark ·
Maybe she's concentrating very hard to keep from falling off that funny looking skateboard she's standing on in high heels?
Ashley Pomeroy ·
I have to say that if I saw that mannequin standing in an empty amphitheatre, I would start by positioning myself 200 feet away from it and then extending the distance until we were separated by several miles.
I would be worried that it would follow me home.
I would avoid eye contact.
Joshua Richardson ·
I recommend you treat yourself to that 1987 classic, Mannequin, if you haven’t before.
Ashley Pomeroy ·
I have to say that if I saw that mannequin standing in an empty amphitheatre, I would start by positioning myself 200 feet away from it and then extending the distance until we were separated by several miles.
I would be worried that it would follow me home.
I would avoid eye contact.
Joshua Richardson ·
I recommend you treat yourself to that 1987 classic, Mannequin, if you haven't before.
Baconator ·
There is an app for that... ;)
https://dofsimulator.net/en/
GuyWith ·
What an awesome story. I’ve never seen anything on the web quite so useful in relation to focal length.
Bravo!
GuyWith ·
What an awesome story. I've never seen anything on the web quite so useful in relation to focal length.
Bravo!
Greg ·
Thanks for posting this.
For me, in choosing a focal length, there are two questions I may be asking. One is the one answered here, which is “I’m going to be standing so far from my subject, what focal length should I use?”
However, more often, I’m wondering “I want to take an upper body shot of my subject, what will the overall picture (including the background) look like with different focal lengths?” If y’all are feeling masochistic, that would be a very helpful comparison. I realize that one’s more difficult, since it requires shooting from different distances for each focal length, rather than just changing the lenses on the camera at each distance.
At a minimum, it seems like a 5ft version of this would be helpful, to be able to see a tighter 35mm example.
Greg ·
Thanks for posting this.
For me, in choosing a focal length, there are two questions I may be asking. One is the one answered here, which is "I'm going to be standing so far from my subject, what focal length should I use?"
However, more often, I'm wondering "I want to take an upper body shot of my subject, what will the overall picture (including the background) look like with different focal lengths?" If y'all are feeling masochistic, that would be a very helpful comparison. I realize that one's more difficult, since it requires shooting from different distances for each focal length, rather than just changing the lenses on the camera at each distance.
At a minimum, it seems like a 5ft version of this would be helpful, to be able to see a tighter 35mm example.
Calaverasgrande ·
no mention of AOV?
It’s kind of a hard to grasp subject.
What I did once years ago, was take the same shot from different distances, and used the zoom on the lens I had at the time to frame the picture identically. On a face it is hard to see, due to how our brain detects faces. So it’s easier to see if you pick a static object like a house or a car.
A wider focal length will have to be much closer to the subject. Taking a house for example. You won’t even see the top of the eaves if you are 10 feet away.
With a longer focal length you may have to be across the street to frame the picture the same. so now you are seeing the top of the eaves and maybe some other things you cant see up close. But then some details aren’t going to be the same due to the distance.
There is also that effect that wider lenses make faces look fatter, or more goofy. Exaggerating the nose and ears.
This is why 85mm and up are often favored for portrait. 50mm and up on APSC.
Calaverasgrande ·
no mention of AOV?
It's kind of a hard to grasp subject.
What I did once years ago, was take the same shot from different distances, and used the zoom on the lens I had at the time to frame the picture identically. On a face it is hard to see, due to how our brain detects faces. So it's easier to see if you pick a static object like a house or a car.
A wider focal length will have to be much closer to the subject. Taking a house for example. You won't even see the top of the eaves if you are 10 feet away.
With a longer focal length you may have to be across the street to frame the picture the same. so now you are seeing the top of the eaves and maybe some other things you cant see up close. But then some details aren't going to be the same due to the distance.
There is also that effect that wider lenses make faces look fatter, or more goofy. Exaggerating the nose and ears.
This is why 85mm and up are often favored for portrait. 50mm and up on APSC.
Michael Clark ·
Re: depth of field. The linked DoF calculator assumes a display size of 8x10" viewed from a distance of 10" by a person with "manufacturer assumed" visual acuity. The disclaimer is way down at the bottom of the page, as it is with most DoF calculators if they include one at all.
"Note: given the sensor size, the circle of confusion is calculated assuming a print size of 8''×10'' (20cm×25cm), a viewing distance of 10" (25cm) and the manufacturers standard visual acuity."
Many photographers totally miss the fact that both display size and viewing distance affect our perception of depth of field. If the DoF calculator assumes an 8x10" display size and we're looking at a 6000 x 4000 pixel 24MP image at 100% on a 96 ppi monitor (a typical 23" FHD monitor, for example), we're looking at a portion of a 62 x 42 inch display size! The DoF will be much shallower than if we were viewing the same image at an 8 inch height from 10 inches unless we're looking at the monitor from a distance of 52 inches! If our image file is an 8400 x 5600 pixel 47MP image, looking at it on the same 96 ppi monitor gives us a 104 x 84 inch enlargement! Now we need to be at 104 inches (8 feet 8 inches) from the monitor for the DoF to hold if calculated using the standard assumptions (8 x 10" viewed from 10")!
There are a few online DoF calculators that allow "advanced" users to enter display size and viewing distance. Cambridge in Color has one. even there, one must click the "show advanced" button to use the feature. It's at : https://www.cambridgeincolo...
steviegsuccess ·
This is a brilliant and helpful tutorial, thank you, for taking the time to put it together for us.
steviegsuccess ·
This is a brilliant and helpful tutorial, thank you, for taking the time to put it together for us.
Ovette Abejuela ·
I hope there was an 85
Ovette Abejuela ·
I hope there was an 85
Calida Jenkins ·
This is a fantastic guide for understanding focal lengths and sensor sizes! I really appreciate the visual examples and the detailed explanation of how sensor size and distance affect your shots. One thing that often confuses me, though, is the conversion between focal lengths for different sensor sizes. I found the table with focal length multipliers super helpful for clearing that up. For added accuracy, I also used a mm to feet converter https://centimeterto.com/mm-to-feet to ensure my measurements were spot-on. Thanks for making a complex topic much more accessible!