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New Contributor
Posts: 3
Registered: ‎07-23-2020

Read Depth of field with EXIF data

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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VIP
Posts: 10,189
Registered: ‎08-13-2015

Re: Read Depth of field with EXIF data

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.

 

A557FCF0-2474-4A23-980A-77488FE7DC53.jpeg

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"Doctor told me to get out and walk, so I bought a Canon."
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New Contributor
Posts: 3
Registered: ‎07-23-2020

Re: Read Depth of field with EXIF data

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

 

   EXIF 
FileDistance cm FocusUpperFocusLowermm 
       
Cm30_7_130 32311 
Cm30_830 0,320,31  
Cm30_1030 0,320,31  
Cm30_1430 0,320,31  
Cm50_7_150 54504 
Cm50_850 0,540,5  
Cm50_1050 ====  
Cm50_1150 ====  
Cm50_1650 ====  
Cm70_7_170 74677 
Cm70_870 ====  
Cm70_1070 ====  
Cm70_1170 ====  
Cm70_1670 ====  
Cm80_7_180 83749 
Cm80_880     
Cm80_1080     
Cm80_1180     
Cm80_1680     
Cm100_7_1100 1099613 
Cm100_8100     
Cm100_10100     
Cm100_11100     
Cm100_16100     
       

 

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VIP
Posts: 10,189
Registered: ‎08-13-2015

Re: Read Depth of field with EXIF data


@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

 

 

 


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.

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"Doctor told me to get out and walk, so I bought a Canon."
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New Contributor
Posts: 3
Registered: ‎07-23-2020

Re: Read Depth of field with EXIF data

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

 

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