Calculating TStop to achieve a specific DOF with a specific lens

[eco_bach]

Shooting a tracking shot using a 24-70Mk2L Canon zoom at 24 mm.

I need perfect focus from roughly 3-15ft.

How do I calculate the correct T-stop required?

 

[j1clark@ucsd.edu]

Shooting a tracking shot using a 24-70Mk2L Canon zoom at 24 mm.

I need perfect focus from roughly 3-15ft.

How do I calculate the correct T-stop required?

You find an online tool, or use one of the handy smart phone apps.

Here are two I use:

pCam

Toland

 

[hscully]

Here's another on iTunes if you have an iPhone. I use it all the time https://itunes.apple.com/us/app/simple-dof-calculator/id301222730?mt=8

 

[Samuel H]

And my web-based one:
http://www.similaar.com/foto/dof/dof.php
http://www.similaar.com/foto/dof/dof2.php

Keep in mind: T-stop will tell you more accurately how much light hits the sensor, but f-stop is the one that controls DoF (i.e. light absorption by the different glass elements doesn't affect DoF)

 

[Shooter]

How do I calculate the correct T-stop required?

You will note from the Tools the others has suggested that it is a combination of a Stop Setting plus a Focus Mark that is required to achieve your DOF goal.

They interact with each other .

 

[Bern Caughey]

f-stops are used to calculate DOF, & T-Stops are used for calculating exposure.