Macrophotography - the silly 1:1 criterion

[Doug Kerr]

We continue to encounter reference to the silly "image magnification of at least 1:1" criterion as a benchmark of "true macrophotography".

A typical context is:

"Although the DMC-FZ200 can focus as close as 1 cm, it does not attain [an image magnification of] 1:1"​

What do we mean by "macrophotography"? We generally mean "the photography of small objects".

That seems strange, given that macro means "large". But the term first emerged as a way to describe the photography of small objects that were large enough that they did not need to be photographed "through a microscope" (microphotography). That is, objects that were not (quite) "microscopic" were "macroscopic".​

Now, what is our real objective here. Just to be able to photograph a "small" object? Well, with a 35 mm lens on my dSLR I can photograph a postage stamp at a distance of 25 feet. We don't mean that.

We mean the ability to fill a substantial part of the frame with our object, so it will fully benefit from the resolution of the camera.

So what then is a "small" object? Well, certainly there is no really meaningful definition—nor is one really needed, or useful. But let's look at the implications of the notion that "microphotography really exists when the image magnification is at least 1:1".

If I have an "8 x 10" film camera, with a setup that gives me an image magnification of 1:1, I can well fill the frame with a ladies' high-heeled shoe.

With a "full frame 35-mm format" digital camera and an image magnification of 1:1, I can well fill the frame with a very large postage stamp.

With a four-thirds format digital camera and an image magnification of 1:1, I can well fill the frame with the "portrait" on a small postage stamp.

With our new Lumix DMC-FZ200 * (7.7 mm sensor**) and an image magnification of 1:1, I can well fill the frame with a medium-sized ant.

* On the UPS truck as we speak.

** We have decided that in general, to describe the size of a digital camera sensor, we will state its size.​

So isn't attainment of an image magnification of 1:1 a silly benchmark for the attainment of "real macrophotography"?

To describe the "macrophotographic" capabilities of a certain camera (body and lens), we would be well served to quote the size of the smallest "object frame" that could be made to fill the frame. And not screw around with the notion of "is this real macrophotography".

Best regards,

Doug

 

[Bart_van_der_Wolf]

We continue to encounter reference to the silly "image magnification of at least 1:1" criterion as a benchmark of "true macrophotography".

Hi Doug,

I don't care too much about what others might call "true macrophotography". BTW the formal description of this type of photography is called "Photomacrography". Those who require the qualification of 'true' to make their point are often caught in some type of dogmatic thinking. I prefer to keep an open mind and leave room to learn something.

What can be important in this type of photography is to allow calibration of the measurements that are made later, based on the recorded image dimensions. Many objects/subjects do not allow to include a calibration reference alongside the object at shooting time, which is when it becomes useful to know the magnification factor that was used to record the object. That will allow an almost direct scaling of the sensor image dimensions to the actual object dimensions.

I agree that this doesn't allow to intuitively grasp the maximum size of object one can fill the frame with, without knowing the sensor dimensions. That is the practical angle towards planning a shot, how large is the object in the plane of focus, how large is the sensor, ergo what is the required magnification factor, and can we achieve that given the focal length and minimum focus distance.

With our new Lumix DMC-FZ200 * (7.7 mm sensor**) and an image magnification of 1:1, I can well fill the frame with a medium-sized ant.

** We have decided that in general, to describe the size of a digital camera sensor, we will state its size.​

Diagonal size (6.17 x 4.55 mm, diagonal 7.67mm), agreed.

To describe the "macrophotographic" capabilities of a certain camera (body and lens), we would be well served to quote the size of the smallest "object frame" that could be made to fill the frame.

Yes, that can be useful. However, it is often possible to adjust the close-up capabilities with an additional converter lens.

Here I used an old/spare 50mm lens, handheld in reverse in front of the fixed zoom lens, combined with the "macro" setting of a simple Canon Powershot G3, to shoot an itsy-bitsy spider of about 1-1.5mm if I recall correctly:

I could have measured it quite accurately, had I known the magnification factor, but on that occasion measuring was not what I intended to do. Getting the shot was challenging enough, given the limited means.

Cheers,
Bart

 

[Doug Kerr]

Hi, Bart,

BTW the formal description of this type of photography is called "Photomacrography".

Indeed. I used the term we most often see in the context of this issue.

However, it is often possible to adjust the close-up capabilities with an additional converter lens.

Yes, and I originally referred to a camera "setup", but backed off for simplicity's sake!

Here I used an old/spare 50mm lens, handheld in reverse in front of the fixed zoom lens, combined with the "macro" setting of a simple Canon Powershot G3, to shoot an itsy-bitsy spider of about 1-1.5mm if I recall correctly:

I could have measured it quite accurately, had I known the magnification factor, but on that occasion measuring was not what I intended to do. Getting the shot was challenging enough, given the limited means.

A wonderful, and wondrous, result.

Thanks.

Best regards,

Doug