Depth of field calcuations with a D500 and 24-70mm

[gossamer]

Hi, I'm hoping to take a few portrait pictures today with my D500 and the 24-70mm lens. I expect to shoot at either f2.8 or f3.2 and trying to determine where I should stand with respect to where the subject should stand to get the best picture and blur the background (trees/greenery). There is nothing between me and the subject.

I'm using dofmaster for my calculations, using the D300, since the D500 isn't listed.

According to dofmaster, it should be between 9.67ft and 10.4ft, using 10ft as the hyperfocal distance.

Can someone confirm for me, that using simple language, if I stand 10ft from the subject, she will be in focus, and the area between 9.67ft and 10.4ft will be in focus, while the area past her to infinity will be out of focus?

Depth of Field Table

 

[Ysarex]

Hi, I'm hoping to take a few portrait pictures today with my D500 and the 24-70mm lens. I expect to shoot at either f2.8 or f3.2 and trying to determine where I should stand with respect to where the subject should stand to get the best picture and blur the background (trees/greenery). There is nothing between me and the subject.

I'm using dofmaster for my calculations, using the D300, since the D500 isn't listed.

According to dofmaster, it should be between 9.67ft and 10.4ft, using 10ft as the hyperfocal distance.

Can someone confirm for me, that using simple language, if I stand 10ft from the subject, she will be in focus, and the area between 9.67ft and 10.4ft will be in focus, while the area past her to infinity will be out of focus?

Depth of Field Table

You're over thinking this and you're getting terms confused (hyperfocal distance doesn't matter for what you're doing). First: Frame the photo to render a good composition. That determines how far you stand back from your subject. That is much more important than DOF distribution -- don't compromise that. You have a zoom lens. If you're goal is to gain a shallow DOF then use the long end of the zoom range (70mm) but don't otherwise compromise the composition and framing of the photo. How blurry the background will appear is predominantly controlled by subject/background separation and secondarily by the lens f/stop. In simple language that means move your portrait subject as far from the background as possible. Finally use an f/stop in the f/2.8 to f/5.6 range. If you're doing a fairly tight face shot lean towards f/5.6 and if you're doing a waist up or 3/4 shot you can lean the other way. Focus on th subjects eyes (eye closest to you) and stop looking up DOFMaster tables.

Joe

 

[gossamer]

You're over thinking this and you're getting terms confused (hyperfocal distance doesn't matter for what you're doing). First: Frame the photo to render a good composition. That determines how far you stand back from your subject. That is much more important than DOF distribution -- don't compromise that. You have a zoom lens. If you're goal is to gain a shallow DOF then use the long end of the zoom range (70mm) but don't otherwise compromise the composition and framing of the photo. How blurry the background will appear is predominantly controlled by subject/background separation and secondarily by the lens f/stop. In simple language that means move your portrait subject as far from the background as possible. Finally use an f/stop in the f/2.8 to f/5.6 range. If you're doing a fairly tight face shot lean towards f/5.6 and if you're doing a waist up or 3/4 shot you can lean the other way. Focus on th subjects eyes (eye closest to you) and stop looking up DOFMaster tables.

Thanks so much for your help.
Do you have any suggestions on the preferred focus method for my D500?

I'm currently using:

- 3D tracking face detection
- AF55 focus points
- Dynamic area AF assist
- Matrix metering
- Face detection
- Center weighted average

Is there anything else I should check? Would spot metering be better?

 

[dunfly]

Most of the pros know instinctively what the focus distance and depth of field is for different settings just from their experience. I'm not a pro so sometimes I need some guidance on hyperfocal distance, where the near and far focus limits are and depth of field. I use an I-phone app to help out. The one I use is Field Tools which cost a whopping $0.00. It is by Brad Sokol. You can load in your camera and lenses although I don't know if the D500 is in the database. It is not perfect but a lot better than guessing. I'm sure there are also Android apps.

 

[Ysarex]

You're over thinking this and you're getting terms confused (hyperfocal distance doesn't matter for what you're doing). First: Frame the photo to render a good composition. That determines how far you stand back from your subject. That is much more important than DOF distribution -- don't compromise that. You have a zoom lens. If you're goal is to gain a shallow DOF then use the long end of the zoom range (70mm) but don't otherwise compromise the composition and framing of the photo. How blurry the background will appear is predominantly controlled by subject/background separation and secondarily by the lens f/stop. In simple language that means move your portrait subject as far from the background as possible. Finally use an f/stop in the f/2.8 to f/5.6 range. If you're doing a fairly tight face shot lean towards f/5.6 and if you're doing a waist up or 3/4 shot you can lean the other way. Focus on th subjects eyes (eye closest to you) and stop looking up DOFMaster tables.

Thanks so much for your help.
Do you have any suggestions on the preferred focus method for my D500?

I'm currently using:

- 3D tracking face detection
- AF55 focus points
- Dynamic area AF assist
- Matrix metering
- Face detection
- Center weighted average

Is there anything else I should check? Would spot metering be better?

You can't be using Matrix metering and Center weighted average at the same time -- one or the other. If you have more than one focus point active the camera tendency will be to find the point closest to you and lock that. Assume for example your model is seated with fingers locked over knee and legs crossed and in the bottom of your frame are those hands with locked fingers. They are closer to you than the model's face. Is it those hands that you want in focus because that's what you're likely to get if an active focus point is near them? Are you going to need the camera to figure out that you have a person in front of you or do you think you can do that? Learn to activate a single focus point and practice using it until you're confident you can make the camera focus on what you want in focus -- do that from now on.

Metering: Whatever metering mode you select you will still be required to interpret the meter's response and compensate for the meter's inability to assess any variation in the reflective properties of your subject versus the assumed average programmed into the camera. This is a skill for you to learn through considerable practice and there's no getting around that. The center weighted average meter mode will be the most consistent to begin with. The matrix mode is best if you really plan to let the camera make the call. With experience and practice you should be able to improve your skill such that you can do better in the weighted or spot mode than the camera does in matrix mode, but if you're just getting started with this and haven't logged those practice hours then the camera in matrix mode will likely be your best option.

Joe

 

[Designer]

..if I stand 10ft from the subject, she will be in focus, and the area between 9.67ft and 10.4ft will be in focus, while the area past her to infinity will be out of focus?

While your logic is correct, I see some issues.

First; if 70mm is the longest lens you have, you can still "cheat" it some by moving back a little and then cropping to a tighter crop in post.

That hypothetical distance of 10 feet is too close, IMO. The DOF at that distance is only 0.73 ft. or just short of 9 inches. That doesn't give you much lee way.

I'd pick a spot where the background trees are at least 50 feet or more behind your subject.

 

[gossamer]

..if I stand 10ft from the subject, she will be in focus, and the area between 9.67ft and 10.4ft will be in focus, while the area past her to infinity will be out of focus?

While your logic is correct, I see some issues.

First; if 70mm is the longest lens you have, you can still "cheat" it some by moving back a little and then cropping to a tighter crop in post.

That hypothetical distance of 10 feet is too close, IMO. The DOF at that distance is only 0.73 ft. or just short of 9 inches. That doesn't give you much lee way.

I'd pick a spot where the background trees are at least 50 feet or more behind your subject.

I also have a 70-200mm f2.8, but I always felt like I was so far away from the subject. I can create 50ft of distance behind the subject, but it just makes it more difficult to find a shaded area.

What would be a more appropriate distance for my 70mm at f2.8 or f3.2?

 

[Designer]

I also have a 70-200mm f2.8, but I always felt like I was so far away from the subject. I can create 50ft of distance behind the subject, but it just makes it more difficult to find a shaded area.

What would be a more appropriate distance for my 70mm at f2.8 or f3.2?

I would definitely use the 200mm.

You want background blur? That's how to get it.

Instead of trying to find shade, go out in the very early morning, and let the low morning sun shine directly onto your subject's face. When the sun is low in the sky, people will not be distressed by brilliant sunshine.

Or late afternoon, as you prefer.

The sunshine will probably let you do the portrait without using flash, providing it is illuminating the face.

 

[Derrel]

Nikon's 3-D Matrix metering can determine skin tones, based on color, and can measure reflectance values from said skin tones. The metering is fairly "smart" and there's very,very little interpreting needed.

STAY AWAY from using f/2.8 or f/3.2 unless you know what you're doing, and if you want to have some out of focus shots where focs placement was not 100% perfect at closer distances with a 24-70mm zoom. Wide apertures like f/2.8 or f/3.2 demand extremely precise focus placement, and there's almost no leeway for error when shooting at close distances with those types of wide apertures. Stopping down a bit on closer-range shot, to f/5.6 or even f/6.3, can help to achieve a look of realism, where the entire person is in-focus. For example, at f/2.8 on a half-body, close0range shot of a woman...if you focus on the eyes, her bosom might very well be renderd as out of focus, and this can be distractring and can look "affected", as I call it.

When doing portraits, I like the entire person to be in a band of crisp,sharp focus! None of this "only the near eye in-focus" stuff for me! I like to have the lens stopped down to f/5.6 or f/6.3 or even f/7.1, so that I have a BAND of focus to work within! Not six inches, but more like 18 inches or more, of acceptable, sharp focus; I want a depth of field that can allow the subject to move a little bit, before the focus area becomes too far forward or back. I want BOTH eyes AND the tip of the nose and the bosom to be in good focus! This means, at closer subject distances or with longer lenses, stopping the lens down, often to f/7.1 or f/8.

Work more on good pictures than on shallow DOF. Try some shots at f/4.5 to f/5.6, to get things SHARP, and lloking "real", and not "affected".

The 24-70mm lens is not really a great portrait lens at the shorter lengths, since you'd often be pretty close-in with the zoom in its 24 to 50mm range, so for half-body and tighter shots, keep the lens in the 70mm to 50mm range, and pay attention to the background diastance BEHIND the subject! Keep the backdrop FAR away to keep it as defocused as possible; if the background contributes to the scene, then dont worry about defocusing it so much.

Stay AWAY from spot metering unless you really KNOW, exactly, how to use it!

 

[gossamer]

So much amazing advice. Thank you all so much for spending the time to help me. Your affirmation of many of the things I've understood but weren't completely clear are appreciated.

Here's a pic I did as a test before trying to go again tomorrow morning. This is with the 70-200mm at 200mm (really 300mm) at f2.8 with my Flashpoint XPLOR 600 set at 1/128. I thought it was important to have at least some light from the strobe for the catchlight.

I'm not sure how the color looks here because I saved it small enough to fit here.

 

[Derrel]

Color looks realistic. I agree--having the flash is worth it, just for the eye catchlights.

As far as the distance: never shoot at closer than 7 feet for a single person, but instead, use a longer lens length. As far as distance and frame size: at 20 feet an 85mm lens shoots a picture area that is 8.47 feet tall on FX Nikon...to get the same frame height, 8.47 feet, a DX Nikon and 85mm lens needs to be around 34.5 feet away. So, what distance depends on the frame area desired...the half-body shot of Melissa could be made from closer, or farther, depending on the focal length used.