Question re DoF calculator

[Mirage]

Colin,

I joined this site in order to seek advice on how to use the Cambridge in Colour Depth of Field Calculator for a 15.6mm x 23.5mm APS-C sensor camera (Ricoh GRiii and GR iiix specifically). The calculator seems to have an APS category but there are a broad range of sensor sizes within the APS category. Thus, I not sure if that is the correct camera category for me to use in the calculator.

Could you please suggest how I should try to determine which camera category in the calculator would be accurate for my sensor size or whether it simply does not cover such APS-C cameras?

Regards

Mark

[lunaticitizen]

If you're okay with another website's DOF calculator you can try this:
https://www.pointsinfocus.com/tools/depth-of-field-and-equivalent-lens-calculator/#{%22c%22:[{%22av%22:%228%22,%22fl%22:18.3,%22d%22:1829,%22cm %22:%220%22}],%22m%22:0}

You can choose 'Custom' in the 'Sensor Size' field and then you can just input '23.5x15.6' without single quotes.

[Round Tuit]

Welcome to CiC.
Your camera uses crop factor of 1.5

[xpatUSA]

Mark,

It sounds like you are quite concerned about determining an accurate DOF for your camera and lens.

If you shoot scenery, i.e. landscapes, cityscapes and such, it is actually possible to forget complicated DOF calculations and still get satisfactory pictures. May I suggest that you read the following a few times and then give it a try:

http://www.trenholm.org/hmmerk/DOFR.html

A case in point too is that even if you were to calculate DOF for a shot to within a millimeter or two - as soon as you resize the image for any reason, the DOF changes!

Another point is that most DOF calculators follow convention by assuming that the output image is an 8x10-inch print viewed at 10 inches from your nose. How many people do that these days?! I myself view only on a 24-inch monitor from about 18" distance - meaning that the conventional DOF calculator does not apply.

Furthermore, I am short-sighted but do not wear glasses at the computer. That effectively changes the CoC which in turn changes the actual DOF.

In other words, getting a good DOF is a bit of a crap-shoot and on-line calculators only get you in the ball-park and, frankly, entering your exact sensor dimensions could be a waste of your time, sorry to say.

Some further reading on thinking "outside the box" re: DOF ...

http://www.trenholm.org/hmmerk/TIAOOFe.pdf

http://kronometric.org/phot/iq/DepthOfField-Lyon.pdf

Both heavy going but worth it, IMHO ...

[Manfred M]

Ted - what you write is all technically correct.

That being said, CiC DoF calculator has an "Advanced" mode which is accessed by clicking on the "Show Advanced" label and the user can set image size, viewing distance, etc. to fix those issues.

The one rule of thumb I was taught many years ago was to stop down one more stop than the calculator shows, just to be safe. The distance markings on modern autofocus lenses are not particularly accurate, if they are shown at all...

[William W]

. . . I joined this site in order to seek advice on how to use the Cambridge in Colour Depth of Field Calculator for a 15.6mm x 23.5mm APS-C sensor camera (Ricoh GRiii and GR iiix specifically) The calculator seems to have an APS category but there are a broad range of sensor sizes within the APS category. Thus, I not sure if that is the correct camera category for me to use in the calculator.

Could you please suggest how I should try to determine which camera category in the calculator would be accurate for my sensor size or whether it simply does not cover such APS-C cameras?

Use the drop down menu and select "Digital SLR with CF of x1.5"



WW