amfoto1 Loc: San Jose, Calif. USA

Nearly all DoF calculators ask you the format of your camera. In your case you would choose "APS-C" or "Canon APS-C" or "1.6X" or "T7i" if they actually ask the camera model. If they don't include your specific camera, choose any of the Canon APS-C models including all the Rebel series, M-series mirrorless, the 80D and it's precursors, and the 7D-series are APS-C models all have very close to the same size sensor.

If the DoF calculator asks you to choose camera model/sensor format DO NOT also convert the lens using the 1.6X multiplier. Simply choose 50mm, in the case of a 50mm lens.

If the DoF calculator doesn't ask you the senor format, use the 1.6X multiplier. However, this is unlikely. I don't know of any DoF calculator that doesn't take sensor format into account by asking you to choose either the camera model or the sensor format.

photogeneralist Loc: Lopez Island Washington State

Depth of field is dependent on the actual focal length of the lens (as well as aperture diameter). Angle of view is effected by the combination of lens focal length and crop factor.

burkphoto Loc: High Point, NC

That works only if your camera supports DOF preview. On some dSLRs, once you stop down a few, you can't see anything, anyway. DOF Calculators on computers and smartphones are like incident meters... they're there when you need them. I've used one on my devices for a decade or more.

burkphoto Loc: High Point, NC

Mine asks for a camera model and calculates based on the specs for it.

Delderby Loc: Derby UK

Is your statement meant to be a "stand alone" statement, for any circumstance?

rehess Loc: South Bend, Indiana, USA

and actual sensor size in calculator.

Race Raccoon Loc: Yankton, South Dakota

Seems the OP's question was only dealing w/DOF, so thinking all these other calculations & formulae may be confusing.

photogeneralist Loc: Lopez Island Washington State

50mm x 1.6 = 80mm. The 80mm result gives the effective focal length.

Or put another way, the 50mm lens equates to an 80mm lens in focal length when used on a cropped sensor camera.




Let me jump in here.
Folks are confusing focal length with angle of view. With any given lens focal length, the angle of view comes smaller or larger following the size of the sensor. The sensor incepts a smaller or larger part of a lenses projected image depending on the size of the sensor For ease of understanding we (inaccurately) say that a 100 mm lens on a 1.5 crop sensor camera is equal to a 150 mm lesson a full frame camera. But in truth , only the angle of view is equal. The depth of field is not changed by the size of the sensor onto which a lens is focusing it's light. The dof of the center portion of a full frame camera (all the things being equal) should be the same as the DOF of a crop sensor image. (the crop sensor due to it's smaller size intercepts a smaller angle of view is all) A 50 mm lens at any equal f stop will have the same DOF regardless of the size of the sensor on which it's focusing the light.
Noted expert Tony Northup has a video in which he argues the crop factor also has an effect on f/stop. I did not follow his geometric logic on that argument though.

RWR Loc: La Mesa, CA

Depth of field is dependent upon the reproduction ratio and aperture - the lens focal length is immaterial.

rehess Loc: South Bend, Indiana, USA

Then why do the calculators include Focal Length and Subject Distance??

https://www.cambridgeincolour.com/tutorials/dof-calculator.htm

photogeneralist Loc: Lopez Island Washington State

So you are telling me that a close up with a wideangle has the same DOF as a telephoto if both are taken at the same aperture and presented at the same percentage of size of the frame?
If a photo is taken with a lens that has a 10 mm dia aperture and the lens has a 14 mm focal length then the photo is taken at a F/1.4 f-stop.
If a photo is taken with a lens that has the same 10 mm dia aperture but has a 100 mm focal length then the photo is taken at f/10. Then by RWR's logic IF THE REPRODUCION RATIOS ARE EQUAL and since the aperture diameter is equal in both cases, then the wide-angle F/1.4 and the telephoto F/10 will have identical Depth of field at identical reproduction ratios. I'll have to check that out on my DOF app (photopills) I'm doubtful.

Since the angle of view is linear, a subject at 10 ft distance at 10 mm the has the same reproduction ratio as if shot from 100 ft with a 100 mm lens
10 mm 10 ft F 1.4 close 5'5" far 71'1" DoF about 66 ft. what is that DoF as a percentage of the focusing subject distance 66/10= 660%
100 mm 100 ft F10 close 62 far 208 DoF about 146 ft what is that DoF as a percentage of the focusing subject distance 146/100= 146%

It appears that RWR's statement was incorrect both in terms of absolute values and percentages.

But wait!

I know what he intended to say and he would have been correct if that is what he had said.
Although he is obviously smart enough to also know what I meant, He called me out because I was not precise enough in my language to specify the the comparison should be at the same subject distances. That obviously rankled me . Now I'm being petty enough to call him out because he used the word Aperture when he meant f-stop (aperture is only one of the factors of f-stop. ( f=A/F where f- f stop, A = aperture diameter, and F= focal length)

RWR Loc: La Mesa, CA

This may explain it better than I:
“Is it true that longer lenses produce a shallower depth of field?

“The focal length of the lens does appear to have a significant impact on depth of field, with longer lenses producing much more blur. A 200mm lens focused at 12ft will have a wafer-thin depth of field compared to a 20mm lens focused at 12ft.

“However, if the subject occupies the same proportion of the frame, the depth of field (the area that appears sharp) is essentially the same whether you're shooting with a wide-angle lens or a telephoto!

“You would, of course, have to move closer with a wide lens or further away with a telephoto lens to maintain the same subject size.”
Full article here:
https://www.techradar.com/how-to/photography-video-capture/cameras/what-is-depth-of-field-how-aperture-focal-length-and-focus-control-sharpness-1320959

Edit: I only use this calculator: http://www.photopills.com/calculators/dof-macro

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

You need to state which DoF calculator you are using. If you are using DoFMaster, for instance, you'll need to provide the actual focal length (not the effective length) and the camera type - it is smart enough to know that the circle of confusion is .019mm for Canon, .020mm for most other APS-C cameras. The calculator does the rest.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

But with the smaller circle of confusion, the DoF must have the correct CoC or the calculation will be off. on a Canon crop camera, the CoC is .019mm, and a 50mm lens at F4 at 10 ft has a total DoF of 1.84 ft. if you used the .03mm CoC of a full frame camera, the total DoF would be 2.94 ft - or 1.84 x 1.6.

kymarto Loc: Portland OR and Milan Italy

DOF is an invariable optical parameter determined by focal length and aperture. Always use the actual focal length for DOF calculations. Only angle of view is determined by crop factor.