Minimum focus distance vs working distance

[dodfr]

Hello,

I was recently reading a few macro lens articles including the new 100mm Sony.

One thing that bother me is that constructors always show Minimum Focus Distance value but rarely the Minimum Working Distance that makes a huge difference and from my point of view a much more interesting information.

I say this because if MFD is for example 30 cm but because the lens is 25 cm long plus the small focal length distance between back lens and the sensor let say the minimum distance left between the lens then the object will cannot be closer 4cm that will be the MWD.

This MWD is in my opinion the only distance that matters because it is the one I will use and I want it showed in lens specs right way instade of havging to make mind calculation. MWD is the one that will tell me I may have problem with shadows because of the lens being too close (whenever macro world always have to deal with shadow), this is the one that will tell me I will need to push leaves or grass away if I don't want them to touch my lens and also this is the one that will tell me I must remove the the lens hood because the lens hood may be too long and "eat" the space left between lens and object and may touch the object.

So question is why constructors do not always show the MWD like they do for MFD and macro ratio ?

But may be my question is stupid ? because with my Sony RX10IV, Sony don't even show difference between MWD and MFD as they "wrongly" use MFD term instead of MWD because the 72cm MWD is showed as MFD in specs (this gives 0.5x macro ratio that is insane by the way at such distance) and the MFD is closer to 100cm from object to RX10IV sensor.

So question is why do they not always show in the specs the MWD next to MFD but only MFD ?

Thanks for your upcoming answers.

 

[Lester Lefkowitz]

You have brought up a subject dear to my heart, and one that burns my rear end!

You are absolutely correct; what matters is how much space we have between the FRONT of the lens and the subject: the WORKING DISTANCE, or at closest focus the Minimum Working Distance MWD.

I think the problems stenms from the fact that conventional lenses are used such that the amount of space lost by the physical extent of the lens matters little when the minimum focusing distance is usually measured in feet or meters. For the average photographer, they just want a feel for how close they can get to a subject before they get punched in the face.

But for us close-up/macro nerds, who used UNconventional lenses, it is not uncommon for the physical extent of the lens to take up half of the minimum focusing distance.

How hard would it befor for a macro lens manufacturer to specifiy the actual working distance with the lens at 1X (or also at 1/2X and 1/4X, thank you)?

If I have a need to know prior to a purchase, a google search of reviews usually turns up the information...but not always.

When I becone president of the world, this defect will be corrected...on my first day in office.

Ledster Lefkowitz, author of The Manual of Close-Up and Macro Photography, Volumes I & II

www.MacroPhotographer.net

 

[dodfr]

You have brought up a subject dear to my heart, and one that burns my rear end!

You are absolutely correct; what matters is how much space we have between the FRONT of the lens and the subject: the WORKING DISTANCE, or at closest focus the Minimum Working Distance MWD.

I think the problems stenms from the fact that conventional lenses are used such that the amount of space lost by the physical extent of the lens matters little when the minimum focusing distance is usually measured in feet or meters. For the average photographer, they just want a feel for how close they can get to a subject before they get punched in the face.

But for us close-up/macro nerds, who used UNconventional lenses, it is not uncommon for the physical extent of the lens to take up half of the minimum focusing distance.

How hard would it befor for a macro lens manufacturer to specifiy the actual working distance with the lens at 1X (or also at 1/2X and 1/4X, thank you)?

If I have a need to know prior to a purchase, a google search of reviews usually turns up the information...but not always.

When I becone president of the world, this defect will be corrected...on my first day in office.

Ledster Lefkowitz, author of The Manual of Close-Up and Macro Photography, Volumes I & II

www.MacroPhotographer.net

Thanks for the answer, so my question was not as stupid as I thought

For example for the latest Sony 100mm macro lens, specs says 26cm MFD for 1.4x but as lens size is 15cm this mean 11cm but you also have to remove the back lens to sensor distance, let say 2 cm so 9cm MWD for 1.4x that increase to 12cm for 1.0x and 18 cm for 0.5x if linear calculation.

And as this lens can receive a TC you may still have 1.0x @ 17,5cm with a TC1.4 or 25cm with a TC2.0 that is much more confortable distance.

But anyway to avoid such calculation this is why we need MWD specs directly in specs sheets from manufacturers because macro lens are for macro photographers and macro photographers do care about MWD not MFD.

 

[Lester Lefkowitz]

You have brought up a subject dear to my heart, and one that burns my rear end!

You are absolutely correct; what matters is how much space we have between the FRONT of the lens and the subject: the WORKING DISTANCE, or at closest focus the Minimum Working Distance MWD.

I think the problems stenms from the fact that conventional lenses are used such that the amount of space lost by the physical extent of the lens matters little when the minimum focusing distance is usually measured in feet or meters. For the average photographer, they just want a feel for how close they can get to a subject before they get punched in the face.

But for us close-up/macro nerds, who used UNconventional lenses, it is not uncommon for the physical extent of the lens to take up half of the minimum focusing distance.

How hard would it befor for a macro lens manufacturer to specifiy the actual working distance with the lens at 1X (or also at 1/2X and 1/4X, thank you)?

If I have a need to know prior to a purchase, a google search of reviews usually turns up the information...but not always.

When I becone president of the world, this defect will be corrected...on my first day in office.

Ledster Lefkowitz, author of The Manual of Close-Up and Macro Photography, Volumes I & II

www.MacroPhotographer.net

Thanks for the answer, so my question was not as stupid as I thought

For example for the latest Sony 100mm macro lens, specs says 26cm MFD for 1.4x but as lens size is 15cm this mean 11cm but you also have to remove the back lens to sensor distance, let say 2 cm so 9cm MWD for 1.4x that increase to 12cm for 1.0x and 18 cm for 0.5x if linear calculation.
And as this lens can receive a TC you may still have 1.0x @ 17,5cm with a TC1.4 or 25cm with a TC2.0 that is much more confortable distance.

But anyway to avoid such calculation this is why we need MWD specs directly in specs sheets from manufacturers because macro lens are for macro photographers and macro photographers do care about MWD not MFD.

Right on, brother!

Lester Lefkowitz