My World: Which lens for Macro?

[fahim mohammed]

Better than 1:1

 

[Tom dinning]

Is that the new toy?

 

[fahim mohammed]

Is that the new toy?

Neither new nor mine, Tom.

Someone wanted to show me what they were seeing in a certain tissue sample of mine. Talk about macro!!

p.s. i did not understand a thing.

 

[Dr Klaus Schmitt]

http://macrolenses.de

Go choose....

 

[Doug Kerr]

I will take this opportunity to remind us that the infamous "1:1" image magnification, often used as the criterion of "real macro performance" for a lens, is not very definitive with regard to our actual photographic needs.

Almost always, what we are really interested in is what sized object (or object field) will fill our frame. At the "1:1" benchmark, that is a field whose size equals the fame size. For a camera with a four-thirds sensor, that would be an object less than 13.5 mm in diameter (about 2/3 the diameter of an American dime coin).

For an 8" × 10" format camera, that object might be a ladies' shoe.

Best regards,

Doug

 

[fahim mohammed]

Sure.

Best regards.

 

[Dr Klaus Schmitt]

I will take this opportunity to remind us that the infamous "1:1" image magnification, often used as the criterion of "real macro performance" for a lens, is not very definitive with regard to our actual photographic needs.

Almost always, what we are really interested in is what sized object (or object field) will fill our frame. At the "1:1" benchmark, that is a field whose size equals the fame size. For a camera with a four-thirds sensor, that would be an object less than 13.5 mm in diameter (about 2/3 the diameter of an American dime coin).

For an 8" × 10" format camera, that object might be a ladies' shoe.

Best regards,

Doug

Ehemm Doug, sorry, but at 1:1 the object size is identical to the size on the sensor, i.e. a 1mm object will be exactly 1mm on the sensor. It has nothing to do with sensor size nor field size, it is a parameter of the lens only.

 

[Asher Kelman]

Klaus, is he starting from the standpoint "where we have no units of measurement", just some camera. In that world one could say that a 1:1 image that fills sheet of film is that size too.

Asher

 

[Doug Kerr]

Hi, Klaus,

Ehemm Doug, sorry, but at 1:1 the object size is identical to the size on the sensor, i.e. a 1mm object will be exactly 1mm on the sensor.. . .

Quite so.

It has nothing to do with sensor size nor field size . . .

Quite so.

. . .it is a parameter of the lens only.

Quite so.

Now, all that having been said, if we are operating at a magnification of 1:1, and our frame size is 36 mm × 24 mm, then the size of the object field (at the object distance for which the magnification is 1:1, at which distance we presumably are focused) will be 36 mm × 24 mm, for the very reasons you cite. If our frame size is 11 in. × 14 in., then the size of the object field is 11 in. × 14 in.

And my point is that if macrophotography is to be thought of as the photography of small (but not microscopic) objects, I don't consider an object that occupies most of an 11 in. × 14 in. region "small".

Best regards,

Doug

 

[Dr Klaus Schmitt]

Absolutely Doug, I just wanted to be clear. Surely, there were lenses built for shipbuilding drawings which copied 1:1, not what I woudl call "m,acro" rather than "repro"

 

[Doug Kerr]

Hi, Klaus,

Absolutely Doug, I just wanted to be clear. Surely, there were lenses built for shipbuilding drawings which copied 1:1, not what I woudl call "m,acro" rather than "repro"

Of course.

Best regards,

Doug