Measuring Background Blur

Measuring background blur can be an important tool when using M4/3 and other smaller sensor cameras, especially for photographers who previously used full frame gear. As humans we often fall into patterns of behaviour, some of which can be counterproductive if we have not adapted to a new situation.

NOTE: Click on images to enlarge.

OM-D E-M1X + M.Zuiko 100-400 mm f/5-6.3 IS @ 253 mm, efov 506 mm, f/6.3, 1/250, ISO-2500, Bird Detection AI Subject Tracking, cropped to 4552 pixels on the width, subject distance 1.6 metres

In a previous article we discussed achieving shallow depth-of-field when using smaller sensor cameras like M4/3.

OM-D E-M1X + M.Zuiko PRO 40-150 mm f/2.8 @ 150 mm, efov 300 mm, f/2.8, 1/1000, ISO-200, subject distance 700 millimetres

The objective of this previous posting was to remind folks that sensor size does not directly impact depth-of-field. Factors like aperture, lens focal length, distance from subject, and distance from subject to background all need to be considered.

OM-D E-M1X + M.Zuiko 100-400 mm f/5-6.3 IS @ 400 mm, efov 800 mm, f/6.3, 1/2500, ISO-5000, Pro Capture H, cropped to 3568 pixels on the width, subject distance 1.6 metres

Over the past number of years I’ve had some interesting chats with photographers when I’ve been out using smaller sensor camera gear. One of the most common misunderstandings that many people have is that shallow depth-of-field cannot be achieved with a smaller sensor camera. This simply is not true.

OM-D E-M1X + M.Zuiko 60 mm f/2.8 macro, f/2.8 1/320, ISO-400, Handheld Hi Resolution, full frame capture, subject distance 270 mm

Shallow depth-of-field can absolutely be achieved with smaller sensor cameras. We just need to adapt our technique when compared to shooting with full frame equipment.

Nikon 1 V3 + 1 Nikkor 70-300 mm f/4.5-5.6 @ 300 mm, efov 810 mm, f/5.6, 1/1000, ISO-2800

I recently came across an interesting online tool that a photographer can use when measuring background blur. This tool is very simple to use and can be instructive when comparing background blur between different camera formats, lenses and apertures.

OM-D E-M1X + M.Zuiko PRO 40-150 mm f/2.8 with M.Zuiko MC-14 teleconverter @ 210 mm, efov 420 mm, f/4, 1/80, ISO-2500, handheld in-camera focus stacking, subject distance 1.2 metres

If you are transitioning from a full frame camera system, considering this as an option, or are interested in shallow depth-of-field, this tool may be of specific benefit to you.

OM-D E-M1X + M.Zuiko 100-400 mm f/5-6.3 IS with MC-14 teleconverter @ 560 mm, efov 1120 mm, f/9, 1/1600, ISO-2500, subject distance 4.9 metres, cropped to 4762 pixels on the width, Bird Detection AI used

The more we understand how to adapt our technique based on the camera gear that we are using, the better able we are to get the maximum performance from it.

Olympus OM-D E-M1X + M.Zuiko 60 mm f/2.8 macro, efov 120 mm, f/8, 1/250, ISO-6400, Handheld Hi Res mode

Experimenting with the measuring background blur tool referenced in this article can be a fun and informative thing to do. I’d suggest reading our previous article about achieving shallow depth-of-field with M4/3, then entering various camera format and lens comparisons on the measuring background blur tool. This may help you consider a wider variety of options and potential lens match-ups.

Technical Note:

Photographs were captured handheld using camera gear as noted in the EXIF data. This is the 1,091st article published on this website since its original inception.

Olympus TG-5 @ 18 mm, efov 100 mm, f/4.9, 1/320, ISO-800, microscopic mode

How you can help keep this site advertising free

My intent is to keep this photography blog advertising free. If you enjoyed this article and/or my website and would like to support my work, you can purchase an eBook, or make a $10 CDN donation through PayPal. Both are most appreciated. You can use the Donate button below. Larger donations can be made to through PayPal.


Word of mouth is the best form of endorsement. If you like our website please let your friends and associates know about our work. Linking to this site or to specific articles is allowed with proper acknowledgement. Reproducing articles, or any of the images contained in them, on another website or in any social media posting is a Copyright infringement.

Article is Copyright 2021 Thomas Stirr. Images are Copyright 2019-2021 Thomas Stirr. All rights reserved. No use, duplication or adaptation of any kind is allowed without written consent. If you see this article reproduced anywhere else it is an unauthorized and illegal use. Posting comments on offending websites and calling out individuals who steal intellectual property is always appreciated!

Leave a Reply

Your email address will not be published. Required fields are marked *