Macro question on ratio in specs

[Satyaa]

I don't shoot macro. Therefore, never tried to understand the specs. My only interest in a lens that says 'Macro' is its ability to focus a bit closer than the non-Macro lenses.

But this question lingers on.

What is the actual definition of the Macro/Reproduction ratio give in the specs?

Internet search result says:
"Magnification Ratio = Image size on sensor : Actual size of subject"

Let's say there is a bug that is 17mm x 13mm in size and its image fills the mft sensor 100%. I understand this as 1:1 macro. Correct?

Let's say the same bug when shot with a FF camera also fills an area of 17x13mm. That lens should also qualify as 1:1 macro. The fact that FF sensor area is approximately four times that of an MFT sensor, and that the image does not fill the entire sensor, does not matter. Correct?

While this question was on my mind for a while, the debate in the comments of Olympus 50-200/2.8 lens announcement article has increased my curiosity to understand this. I don't understand the logic to specify a different ratio as "35mm equivalent". That would be necessary if the ratio was of sensor size itself, not if the ratio is of the captured image size.

What am I missing?

Thanks.

 

[number_5]

While this question was on my mind for a while, the debate in the comments of Olympus 50-200/2.8 lens announcement article has increased my curiosity to understand this. I don't understand the logic to specify a different ratio as "35mm equivalent". That would be necessary if the ratio was of sensor size itself, not if the ratio is of the captured image size.

If you go to OM System 50-200/2.8 spec page, the max mag stated is 0.25x, and when they specify the "35mm equivalent," it means they applied the sensor crop factor, and you ended with 0.5x.

 

[Satyaa]

While this question was on my mind for a while, the debate in the comments of Olympus 50-200/2.8 lens announcement article has increased my curiosity to understand this. I don't understand the logic to specify a different ratio as "35mm equivalent". That would be necessary if the ratio was of sensor size itself, not if the ratio is of the captured image size.

If you go to OM System 50-200/2.8 spec page, the max mag stated is 0.25x, and when they specify the "35mm equivalent," it means they applied the sensor crop factor, and you ended with 0.5x.

That's my question! If the actual object is 40mm and is captured on a 10mm area of the sensor, it should be 1:4 ratio (or 0.25x).

How does it matter that the MFT sensor is 17mm or a FF sensor is 35mm long?

Thanks.

 

[lunic]

I don't shoot macro. Therefore, never tried to understand the specs. My only interest in a lens that says 'Macro' is its ability to focus a bit closer than the non-Macro lenses.

But this question lingers on.

What is the actual definition of the Macro/Reproduction ratio give in the specs?

Internet search result says:
"Magnification Ratio = Image size on sensor : Actual size of subject"

Let's say there is a bug that is 17mm x 13mm in size and its image fills the mft sensor 100%. I understand this as 1:1 macro. Correct?

Let's say the same bug when shot with a FF camera also fills an area of 17x13mm. That lens should also qualify as 1:1 macro. The fact that FF sensor area is approximately four times that of an MFT sensor, and that the image does not fill the entire sensor, does not matter. Correct?

While this question was on my mind for a while, the debate in the comments of Olympus 50-200/2.8 lens announcement article has increased my curiosity to understand this. I don't understand the logic to specify a different ratio as "35mm equivalent". That would be necessary if the ratio was of sensor size itself, not if the ratio is of the captured image size.

What am I missing?

Thanks.

The 'equivalent' magnification factor is related to the 'actual area' that can be captured, so it’s an essential spec. Unfortunately, confusion often arises because marketing press releases tend to highlight the larger of the magnification-related numbers, without explaining the underlying process.

This is how 'equivalent magnification' works.

The new M.Zuiko Digital 50–200mm lens can capture a subject area of 69.1 × 51.9 mm at its closest focusing distance when set to 200mm, which corresponds to an actual magnification of 0.25×.

At the same time, a full-frame camera using a 0.50× macro lens can capture an area of 72 × 48 mm at its closest focusing distance. (For comparison, we can change the aspect ratio to 3:2 while keeping the same diagonal length.) Therefore, in terms of the 'actual area' captured in closest focusing distance, you can say two lenses are 'equivalent'.

 

[Myrmeleon]

I don't shoot macro. Therefore, never tried to understand the specs. My only interest in a lens that says 'Macro' is its ability to focus a bit closer than the non-Macro lenses.

But this question lingers on.

What is the actual definition of the Macro/Reproduction ratio give in the specs?

Internet search result says:
"Magnification Ratio = Image size on sensor : Actual size of subject"

Let's say there is a bug that is 17mm x 13mm in size and its image fills the mft sensor 100%. I understand this as 1:1 macro. Correct?

Correct.

Let's say the same bug when shot with a FF camera also fills an area of 17x13mm. That lens should also qualify as 1:1 macro. The fact that FF sensor area is approximately four times that of an MFT sensor, and that the image does not fill the entire sensor, does not matter. Correct?

Correct.

While this question was on my mind for a while, the debate in the comments of Olympus 50-200/2.8 lens announcement article has increased my curiosity to understand this. I don't understand the logic to specify a different ratio as "35mm equivalent". That would be necessary if the ratio was of sensor size itself, not if the ratio is of the captured image size.

What am I missing?

Thanks.

The "35mm equivalent" number specifies at what true (physical) magnification your subject would fill the Full Frame sensor the same amount as it fills the MFT sensor. So if you want the 13 x 17 mm bug to fill the entire Full Frame sensor, you need to shoot it at approximately twice the MFT magnification (2:1 instead of 1:1). It's a bit confusing and I think everyone should use true magnification numbers, not the equivalent ones, to avoid this confusion.

 

[Skeeterbytes]

The subject bug will be actual size on the sensor with a 1X spec lens, working at the closest possible distance. If said bug is 1cm long at 1X it will take 1cm space on the sensor. Sensor format has no effect--it will be 1cm regardless.

We have three Oly macros: 60, 30, 90mm that deliver 1.0X, 1.25X, 2.0X maximum magnification. You can record the 1cm bug as 2cm using max magnification of the 90, but it will spill over the frame edges because the X axis is only 17.3mm.

HTH

Rick

 

[Photongraphy]

While this question was on my mind for a while, the debate in the comments of Olympus 50-200/2.8 lens announcement article has increased my curiosity to understand this. I don't understand the logic to specify a different ratio as "35mm equivalent". That would be necessary if the ratio was of sensor size itself, not if the ratio is of the captured image size.

If you go to OM System 50-200/2.8 spec page, the max mag stated is 0.25x, and when they specify the "35mm equivalent," it means they applied the sensor crop factor, and you ended with 0.5x.

That's my question! If the actual object is 40mm and is captured on a 10mm area of the sensor, it should be 1:4 ratio (or 0.25x).

How does it matter that the MFT sensor is 17mm or a FF sensor is 35mm long?

Thanks.

--
See my profile (About me) for gear and my posting policy. My profile picture is of the first film camera I used in the early 80s, photo credit the internet.

I think this indeed is just marketing BS, in where OM implies that magnification X 'translates to 2X' in FF to get the same image (as in FOV)...

 

[Bassam Guy]

I don't shoot macro. Therefore, never tried to understand the specs. My only interest in a lens that says 'Macro' is its ability to focus a bit closer than the non-Macro lenses.

But this question lingers on.

What is the actual definition of the Macro/Reproduction ratio give in the specs?

Internet search result says:
"Magnification Ratio = Image size on sensor : Actual size of subject"

Let's say there is a bug that is 17mm x 13mm in size and its image fills the mft sensor 100%. I understand this as 1:1 macro. Correct?

Let's say the same bug when shot with a FF camera also fills an area of 17x13mm. That lens should also qualify as 1:1 macro. The fact that FF sensor area is approximately four times that of an MFT sensor, and that the image does not fill the entire sensor, does not matter. Correct?

While this question was on my mind for a while, the debate in the comments of Olympus 50-200/2.8 lens announcement article has increased my curiosity to understand this. I don't understand the logic to specify a different ratio as "35mm equivalent". That would be necessary if the ratio was of sensor size itself, not if the ratio is of the captured image size.

What am I missing?

Thanks.

The definition of the term "macro" is an unfortunate relic of film days and means exactly what you said (although it is 17.3mm wide, not 17mm). With a FT (MFT) sensor, a 1:1 photo of a metric ruler will be exactly 17.3mm wide on the sensor itself. With 35mm film/sensor (which is really 36mm wide), a 1:1 photo will be exactly 36mm wide on the film/sensor.

You are missing nothing.

 

[Satyaa]

I don't shoot macro. Therefore, never tried to understand the specs. My only interest in a lens that says 'Macro' is its ability to focus a bit closer than the non-Macro lenses.

But this question lingers on.

What is the actual definition of the Macro/Reproduction ratio give in the specs?

Internet search result says:
"Magnification Ratio = Image size on sensor : Actual size of subject"

Let's say there is a bug that is 17mm x 13mm in size and its image fills the mft sensor 100%. I understand this as 1:1 macro. Correct?

Let's say the same bug when shot with a FF camera also fills an area of 17x13mm. That lens should also qualify as 1:1 macro. The fact that FF sensor area is approximately four times that of an MFT sensor, and that the image does not fill the entire sensor, does not matter. Correct?

While this question was on my mind for a while, the debate in the comments of Olympus 50-200/2.8 lens announcement article has increased my curiosity to understand this. I don't understand the logic to specify a different ratio as "35mm equivalent". That would be necessary if the ratio was of sensor size itself, not if the ratio is of the captured image size.

What am I missing?

Thanks.

The 'equivalent' magnification factor is related to the 'actual area' that can be captured, so it’s an essential spec. Unfortunately, confusion often arises because marketing press releases tend to highlight the larger of the magnification-related numbers, without explaining the underlying process.

This is how 'equivalent magnification' works.

The new M.Zuiko Digital 50–200mm lens can capture a subject area of 69.1 × 51.9 mm at its closest focusing distance when set to 200mm, which corresponds to an actual magnification of 0.25×.

At the same time, a full-frame camera using a 0.50× macro lens can capture an area of 72 × 48 mm at its closest focusing distance. (For comparison, we can change the aspect ratio to 3:2 while keeping the same diagonal length.) Therefore, in terms of the 'actual area' captured in closest focusing distance, you can say two lenses are 'equivalent'.

I think you nailed it there. May be we need to further clarify to say that the 'capture' in your sentence means fill the frame.

In other words, if a 0.25x macro lens is required to fill the MFT frame with a subject 69x52mm (appx), then a 0.5 macro lens is required to fill the FF frame with a similar object 72x48mm (adjusted for aspect ratio).

When they say equivalent magnification, they are saying fill a different sized frame.

Thanks.

 

[Satyaa]

I don't shoot macro. Therefore, never tried to understand the specs. My only interest in a lens that says 'Macro' is its ability to focus a bit closer than the non-Macro lenses.

But this question lingers on.

What is the actual definition of the Macro/Reproduction ratio give in the specs?

Internet search result says:
"Magnification Ratio = Image size on sensor : Actual size of subject"

Let's say there is a bug that is 17mm x 13mm in size and its image fills the mft sensor 100%. I understand this as 1:1 macro. Correct?

Correct.

Let's say the same bug when shot with a FF camera also fills an area of 17x13mm. That lens should also qualify as 1:1 macro. The fact that FF sensor area is approximately four times that of an MFT sensor, and that the image does not fill the entire sensor, does not matter. Correct?

Correct.

While this question was on my mind for a while, the debate in the comments of Olympus 50-200/2.8 lens announcement article has increased my curiosity to understand this. I don't understand the logic to specify a different ratio as "35mm equivalent". That would be necessary if the ratio was of sensor size itself, not if the ratio is of the captured image size.

What am I missing?

Thanks.

The "35mm equivalent" number specifies at what true (physical) magnification your subject would fill the Full Frame sensor the same amount as it fills the MFT sensor.

That highlighted key phrase was what I was missing.

So if you want the 13 x 17 mm bug to fill the entire Full Frame sensor, you need to shoot it at approximately twice the MFT magnification (2:1 instead of 1:1). It's a bit confusing and I think everyone should use true magnification numbers, not the equivalent ones, to avoid this confusion.

Edit: This part I agree. The size of image captured in relation to the real-life subject should be the metric. They should not adjust it for sensor size. Thank God they didn't invent another ratio for pixel count

 

[DrHook59]

I wouldn't worry at all about the term 'Macro'. It is so abused and argued over nowadays it's not worth getting into a fight about. Just shoot what you want, how you want, at the focal length you want, and enjoy the results. 'Macro' is not a legal requirement for anything but competitions when there are definitive and stupid entry requirements. People shoot bugs at all distances, and as far as I'm concerned people who like insects enjoy them no matter how close or far away they are, without bothering to quantify the image according to some 'rules'. Take your lens, attach it to your camera, look through the viewfinder at your subject and compose according to your intent. Don't get caught up in the technical side of it so much - it's far more fun than that, whether it's a close-up, a macro or a micro image. They all count!

 

[Jens_ac]

I don't shoot macro. Therefore, never tried to understand the specs. My only interest in a lens that says 'Macro' is its ability to focus a bit closer than the non-Macro lenses.

But this question lingers on.

What is the actual definition of the Macro/Reproduction ratio give in the specs?

Internet search result says:
"Magnification Ratio = Image size on sensor : Actual size of subject"

Let's say there is a bug that is 17mm x 13mm in size and its image fills the mft sensor 100%. I understand this as 1:1 macro. Correct?

Let's say the same bug when shot with a FF camera also fills an area of 17x13mm. That lens should also qualify as 1:1 macro. The fact that FF sensor area is approximately four times that of an MFT sensor, and that the image does not fill the entire sensor, does not matter. Correct?

While this question was on my mind for a while, the debate in the comments of Olympus 50-200/2.8 lens announcement article has increased my curiosity to understand this. I don't understand the logic to specify a different ratio as "35mm equivalent". That would be necessary if the ratio was of sensor size itself, not if the ratio is of the captured image size.

What am I missing?

Thanks.

 

[Sdlv]

. . . Let's say there is a bug that is 17mm x 13mm in size and its image fills the mft sensor 100%. I understand this as 1:1 macro. Correct?

Let's say the same bug when shot with a FF camera also fills an area of 17x13mm. That lens should also qualify as 1:1 macro. The fact that FF sensor area is approximately four times that of an MFT sensor, and that the image does not fill the entire sensor, does not matter. Correct? . . .

Roughly correct.

Magnification is invariant to sensor size. Shooting at 1:1, a 17mm bee will project a 17mm image on the sensor, no matter what the sensor size. If the sensor is 17mm, as in MFT, that projection will fill the sensor's width. If using a 35mm FF sensor, the bee's projection will only cover half the field width. The magnification is the same, but when we make the images the same size and place them side by side, the MFT's image gives the illusion of having twice the FF's magnification.

The MFT's field-of-view at 1:1 is (roughly) 17mm; with FF, it's (roughly) 35mm. If the FF user desires to match the match the MFT's 17mm FOV in camera, it requires shooting the FF at 2:1 magnification (rather than 1:1).

. . . Steven

 

[Will Rose]

Satyaa,

Your understanding is correct, and you’re not missing anything.

Macro means that the image of the object produced on the imaging plane (sensor or film) is the same size (at least) as the object itself. A 17mm object is 17mm on the sensor. It’s that simple.

The easiest way to understand it is to imagine you’re taking a picture of a bug. If you picked the bug up and set it on the sensor, that’s 1:1 macro size.

The next important thing to understand is that “macro” is exclusively a property of the LENS. The sensor has nothing to do with it. Imagine our bug. A 17mm bug is 17mm regardless of whether you set him on a tiny phone sensor, or an MFT sensor, or a FF sensor, or a big medium format sensor. The bug is the size he is, 17mm. How big the sensor is or what resolution it has doesn’t change the fact the bug is 17mm.

When you see references to “35mm equivalent magnification” this means the magnification required to fill the frame with the desired object on a FF camera. You'd need a 2:1 macro lens on a full frame camera to fill the frame with an object that fills the frame on MFT at 1:1, simply because the FF sensor is bigger, and so the projected image needs to be bigger to fill it.

This means that when you’re taking pictures at a 1:1 macro reproduction ratio, it is pixel density, as opposed to total pixels, that determines how many pixels you get on your bug. If you have a 17mm bug at 1:1 macro, you would need an 80mp FF sensor to get the same number of pixels on that bug as a 20MP MFT sensor.

I hope this helps.

 

[lunic]

I think this indeed is just marketing BS

NO. Equivalent magnification reflects real-world results.

A 1.0× μ4/3 macro lens can capture the area of 17.3×13mm at its closest focusing distance. To fill a full-frame sensor with an area of 18×12mm, (representing a hypothetical 3:2-ratio 4/3" sensor) you would need a 2.0× magnification lens, not a 1.0×.

 

[James Stirling]

I think this indeed is just marketing BS

NO. Equivalent magnification reflects real-world results.

A 1.0× μ4/3 macro lens can capture the area of 17.3×13mm at its closest focusing distance. To fill a full-frame sensor with an area of 18×12mm, (representing a hypothetical 3:2-ratio 4/3" sensor) you would need a 2.0× magnification lens, not a 1.0×.

The 1:1 definition of macro being subject in real life being the same as the subject on the sensor is a standard definition used universally .

An example amongst my too large macro gear I have the older Nikon F 200mm F/4 , I have used it on FF , APS and even 1" cameras on adapters. The lens remains a 1:1 the difference is in the size of real life object that fits in the smaller sensors.

1:1 macro defintions :

Our host:

https://www.dpreview.com/articles/6519974919/macro-photography-understanding-magnification

Canon, Nikon , Sony , Fuji and Pentax all have different sensor sizes in their gear

Canon:

https://www.eos-magazine.com/articles/eospedia/what-is/macro.html

Nikon:

https://www.nikon.co.uk/en_GB/product/lenses/mirrorless/nikkor-z-mc-105mm-f2.8-vr-s

Sony:

https://www.sony.co.uk/electronics/macro-photography-lenses

Fuji

https://www.fujifilm.com/me/en/news/Introducing-the-FUJINON-XF30mmF2.8-R-LM-WR-Macro

Pentax/Ricoh

https://www.ricoh-imaging.co.jp/english/products/lens/k/macro/

Allan Walls an excellent resource for all aspects of macro photography , both on YT and his website

No rebuttals for whiners

https://www.dpreview.com/forums/post/68429421











--
Jim Stirling:
"To argue with a person who has renounced the use of reason, is like administering medicine to the dead." - Thomas Paine
Feel free to tinker with any photos I post

 

[lunic]

I think this indeed is just marketing BS

NO. Equivalent magnification reflects real-world results.

A 1.0× μ4/3 macro lens can capture the area of 17.3×13mm at its closest focusing distance. To fill a full-frame sensor with an area of 18×12mm, (representing a hypothetical 3:2-ratio 4/3" sensor) you would need a 2.0× magnification lens, not a 1.0×.

(Google Chrome Machine Translation)

https://nij.nikon.com/products/lineup/nikkor/zmount/nikkor_z_dx_mc_35mm_f17/features01.html

So we have another lensmaker using the term "equivalent" in magnification.

"For the first time with a NIKKOR Z DX lens, a maximum magnification of 0.67x (equivalent to life size*1) has been achieved. (...) It also enables dynamic depictions of subjects as small as approximately 2.4 x 3.6 cm, filling the entire frame."

(the 1:1 magnification is often referred as "life size".)

Of course, "equivalent magnification" is often dismissed as marketing BS, but it's actually based on the smallest frame size - which, in a way, reflects the REALITY.

It's genuinely interesting to see how those who, in other contexts, firmly insist on multiplying the crop factor everywhere, now argue against doing so here. I can't seem to stop being intrigued by how people think.