Extreme macro

Started 2 months ago | Questions thread
Gerry Winterbourne Forum Pro • Posts: 17,498
Re: Extreme macro
1

jimhughes wrote:

petrochemist wrote:

jimhughes wrote:

Filters and extension tubes don't increase "magnification" - they just reduce the minimum focus distance. 2 macro lenses of the same focal length might have different minimum focus distances, so the subject will fill different amounts of the frame.

I have a blog post about this:

https://jimhphoto.com/index.php/2020/04/18/macro-confusion/

In macro the magnification is DEFINED as image size/object size. Being able to focus closer (reduced the minimum focus distance) increases the magnification available.

Many macro lenses change their focal length as they are focused closer, this is typically what happens, when you have macro lenses of the same nominal focal length but different MFDs. Note however some macro lenses max out at 1:2, and a few reach 2:1 or more.

That's why I put "magnification" in quotes. What we're really talking about is reproduction ratio.

That may be what you are talking about. I and pertrochemist are talking about magnification as such.

The OP asked about fitting a 1/2 inch object on a Canon APS-C sensor; that's a magnification of about 2:1.

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Gerry
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First camera 1953, first Pentax 1985, first DSLR 2006
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