sippyjug104 Loc: Missouri

These posts may be preaching to the Choir telling many what they have known for quite some time however there are some that read these posts that are starting anew in this venture so please bear with me for I enjoy sharing what we do and how we do it.

The other day I posted information regarding the 'Effective Aperture' when shooting at varying amounts of magnification compared to what the aperture setting on the lens or camera may say.

Today I would like to explain how to determine the amount of magnification achieved for those like myself that use ways of extending the lens, use reverse mounted lens, microscope objectives, etc. other than using a manufactured calibrated magnification lens.

It's a quite simple process so here we go:

First determine the sensor width of your camera. For example a full-frame camera is 36mm wide. A crop APS-C sensor (the one that I am using) is 23.5mm wide.

Second place a scale that measures millimeters in line with the lens and focus on it. We'll refer to this as the frame width that we will be able to count the number of millimeters we see when viewed. In my case it is 'four' millimeters as shown in the image above.

Now we simply divide the width of the camera sensor in millimeters by the number of millimeters we can view in the frame width.

So...a 23.5mm wide sensor divided by 4mm viewed in the frame width = 5.875X magnification with the combination of extension and lens (microscope objective in my case).

Keep in mind that an APS-C sensor camera will have a factor of 1.6X compared to the field of view of a full-frame camera so the the results of the two in comparison will not be the same.

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sscnxy

Please keep up these posts, Sippyjug. We neophytes have much to learn and getting it first-hand from a master has no equal. Thank you!

NY

sscnxy

Please keep up these posts, Sippyjug. We neophytes have much to learn and getting it first-hand from a master has no equal. Thank you!

NY

JimmyTB

I second that. In college some professors would encourage people to ask questions even if they thought that they were dumb questions, because chances are there were many in the class with the same question, just too afraid to ask. You posts like this are sort of the flip side of that coin. These tips and hints that some may think are too basic are just what we neophytes need to help us learn. We can spend days or weeks experimenting with no clue what we are doing or we can learn from those who have already done it and start practicing and experimenting from there. Thank you for your generosity sharing your hard-won knowledge.

sippyjug104 Loc: Missouri

Thanks ever so much for the kind reply. Gosh knows that I have spent an untold amount of time experimenting with gear and techniques with only a glimmer of hope...and stubbornness to keep trying. I have boxes of experimental ways to diffuse the lighting. If I can help others in any way by sharing my experiences then it has all been worth it.

sippyjug104 Loc: Missouri

Thanks, sharing is truly caring and it is one of the few things in life that costs nothing to do.