Question 1

What is the depth of field of the Tamron 20mm F2.8 Di III OSD at f/2.8 and 3 m?

Accepted Answer

At 20mm, f/2.8 and focus at 3 m, acceptable sharpness runs from 1.88 to 7.49 m — about 561 cm in total.

Question 2

What is the hyperfocal distance of the Tamron 20mm F2.8 Di III OSD?

Accepted Answer

At 20mm and f/8 on a Full Frame sensor the hyperfocal distance is about 1.75 m. Focus there and everything from 0.88 m to infinity is sharp.

Question 3

How do I get more background blur with the Tamron 20mm F2.8 Di III OSD?

Accepted Answer

Open the aperture to f/2.8, move closer to your subject and increase the distance between subject and background. You can check the result in the calculator above.

Aperture	Hyperfocal	1 m	2 m	3 m	5 m	10 m
f/2.8	4.97 m	0.84–1.25	1.43–3.32	1.88–7.49	2.50–∞	3.33–∞
f/4	3.49 m	0.78–1.39	1.28–4.63	1.62–20.6	2.06–∞	2.59–∞
f/5.6	2.50 m	0.72–1.65	1.12–9.67	1.37–∞	1.67–∞	2.00–∞
f/8	1.75 m	0.64–2.27	0.94–∞	1.11–∞	1.30–∞	1.49–∞
f/11	1.28 m	0.57–4.26	0.79–∞	0.90–∞	1.02–∞	1.14–∞
f/16	0.89 m	0.48–∞	0.62–∞	0.69–∞	0.76–∞	0.82–∞
f/22	0.65 m	0.40–∞	0.49–∞	0.54–∞	0.58–∞	0.61–∞

Tamron 20mm F2.8 Di III OSD — depth of field calculator

Key numbers

Depth of field table

FAQ

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