How do you know it's actually macro with a digital camera?

[Terry McDaniel]

With film you can always measure the image on the negative and measure the subject to see if you have true macro. With digital I can take about any photo and crop till it looks macro, but is it true macro? Obviously, you cannot get a large insect completely on a APS-C or smaller sensor. Is it cheating to call a cropped photo a macro photo?
This caterpillar hunter is what I'm talking about. Shot with Nikon P610, in close up mode, probably three or four inches from the bug. Then cropped to just the head and thorax. I'd post it in insects, but won't post it in macro.

 

[Jack Dawe]

Good question. I've often wondered what the difference is between snapping an insect with my 100mm macro lens and my 100-400mm at 100mm.

 

[Darren75]

I don't know. What is true macro? When a bug is frame filling I see it as macro.

 

[JohnPD]

I don't know the first thing about macro, but if it looks like a macro, does it matter how it was achieved?

 

[RichardB]

What is the "official" definition of macro?

 

[Levina de Ruijter]

From the Wiki:

Macro photography (or photomacrography or macrography, and sometimes macrophotography is extreme close-up photography, usually of very small subjects and living organisms like insects, in which the size of the subject in the photograph is greater than life-size (though macrophotography also refers to the art of making very large photographs).

By the original definition, a macro photograph is one in which the size of the subject on the negative or image sensor is life-size or greater. In some senses, however, it refers to a finished photograph of a subject that is greater than life-size.

The ratio of the subject size on the film plane (or sensor plane) to the actual subject size is known as the reproduction ratio. Likewise, a macro lens is classically a lens capable of reproduction ratios of at least 1:1, although it often refers to any lens with a large reproduction ratio, despite rarely exceeding 1:1.

Link

Personally I have always taken macro to be an extreme close-up, no matter how it is achieved.

 

[RichardB]

The original definition is a photo in "which the size of the subject on the negative or image sensor is life-size or greater."

Life-size? When I look at that beetle in the OP, then it is much larger than any beetle in real life is. So what is "life-size" exactly here. An ant is really tiny, but in the photos I see posted they are huge. How can they not be macro? How can that beetle above not be macro?

 

[Levina de Ruijter]

Here's an article from 2011 (from a note in the Wiki) about magnification.

 

[Terry McDaniel]

Thanks for all the comments. This helps: "By the original definition, a macro photograph is one in which the size of the subject on the negative or image sensor is life-size or greater. In some senses, however, it refers to a finished photograph of a subject that is greater than life-size."

 

[JohnPD]

So then your beetle is macro after all?

 

[Levina de Ruijter]

Thanks for all the comments. This helps: "By the original definition, a macro photograph is one in which the size of the subject on the negative or image sensor is life-size or greater. In some senses, however, it refers to a finished photograph of a subject that is greater than life-size."

So it can be both: if the subject on the negative or image sensor is life-size or greater. Or if it's not but cropped to the extent that the subject is life-size or greater. Is that how to interpret this statement?

 

[Terry McDaniel]

That’s what I’m thinking. So I reckon I’ll post bug pictures in the macro thread, if it’s enlarged enough to show detail.

 

[Levina de Ruijter]

That’s what I’m thinking. So I reckon I’ll post bug pictures in the macro thread, if it’s enlarged enough to show detail.

Yes, I agree. Post away!

 

[Archibald]

In common usage, "macro photography" has for many years had a pretty loose meaning. It just means close, probably closer than your normal equipment could easily manage. The formal definition is that the magnification of the image is greater than or equal to 1:1, but I have also heard it stated as greater than 1x.

These definitions aren't very useful, IMO, because they ignore sensor size. Thus, while a frame-filling image of a 3 centimeter bug would be considered macro on a full frame camera, it wouldn't be when taken on a phone.

We don't have a better definition of macro for now, but for most of us, if it looks closer than normal, it is macro.

 

[Jack Dawe]

This helps: "By the original definition, a macro photograph is one in which the size of the subject on the negative or image sensor is life-size or greater.

I get that—in theory. I'm sure I'm being very stupid, but how can you tell that your sensor is showing the subject at a ratio of 1:1? Personally I'll settle for "If it looks like a macro, it's a macro".

 

[Terry McDaniel]

Jack, that was my thought also. Easy to measure an image on a negative, not so easy with a sensor. I suppose there could be a way to count pixels, but I’m not smart enough for that.

 

[Archibald]

Jack, that was my thought also. Easy to measure an image on a negative, not so easy with a sensor. I suppose there could be a way to count pixels, but I’m not smart enough for that.

The whole image is 36mm wide for FF, and about 23mm for crop.

If you are shooting with the RF 100mm macro lens, the magnification is shown in the viewfinder.

You don't need to know the image size, but it isn't hard to work it out if you want to know.

 

[Bryn]

A photo is a macro when the subject is focused on with much sharper-than-usual details, and the rest is slightly blurred out. Then again, the "Macro" setting helps with this wonderfully