Read Depth of field with EXIF data

[SeveBri]

Hi , i take macro photography and the main problem is depth of field .

To check I took pictures with a tripod , always from the same distance, ISO and shutter speed.

I only changed the aperture value. 7,1 -8 -10-16 .

I read the related Exif data focus distance upper / lower , but to my surprise they never change, they are always the same for all the shots.   why is this happening? .

If I use a simulation SW as a DOFsimulator ,this value varies .

I use Eos 5d mark iv + ef 100 L macro

Thanks Alessandro

[Waddizzle]

You did not provide any distance or DoF info.  It is not possible to answer your question without data. I assume that your subject is less than a foot from the camera.  Take a look at the top row of the Depth of Field Table.

[SeveBri]

Hi ,I shoot pictures at different distances, 30 -50-70 80 100 cm the result is in the table .

			EXIF
File	Distance cm		FocusUpper	FocusLower	mm
Cm30_7_1	30		32	31	1
Cm30_8	30		0,32	0,31
Cm30_10	30		0,32	0,31
Cm30_14	30		0,32	0,31
Cm50_7_1	50		54	50	4
Cm50_8	50		0,54	0,5
Cm50_10	50		==	==
Cm50_11	50		==	==
Cm50_16	50		==	==
Cm70_7_1	70		74	67	7
Cm70_8	70		==	==
Cm70_10	70		==	==
Cm70_11	70		==	==
Cm70_16	70		==	==
Cm80_7_1	80		83	74	9
Cm80_8	80
Cm80_10	80
Cm80_11	80
Cm80_16	80
Cm100_7_1	100		109	96	13
Cm100_8	100
Cm100_10	100
Cm100_11	100
Cm100_16	100

[Waddizzle]

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@SeveBri wrote:

Hi , i take macro photography and the main problem is depth of field .

To check I took pictures with a tripod , always from the same distance, ISO and shutter speed.

I only changed the aperture value. 7,1 -8 -10-16 .

I read the related Exif data focus distance upper / lower , but to my surprise they never change, they are always the same for all the shots.   why is this happening? .

If I use a simulation SW as a DOFsimulator ,this value varies .

I use Eos 5d mark iv + ef 100 L macro

Thanks Alessandro

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I am not familiar with any Canon camera that adds Depth of Field to the EXIF data, just an aperture setting.  Your printout is from your simulator,  which is not EXIF data.  These focusing distances are very small, and the estimated DoF are even smaller.

You are probably looking at rounding errors.  The software probably does not have enough significant digits to resolve those small differences in aperture at macro focusing distances.

[SeveBri]

Hi , The values ​​that I have highlighted are the reading of the Exif data of each single photo .

They are not simulated but real data  .  

I wrote them in an excel file. 

It may be that the sw rounds the values, because they are very small.

I will test with a normal lens and with greater distances.

Thanks