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Variable a Focus Lens Sourcing

Started Sep 21, 2018 | Discussions
SmoothOperator Regular Member • Posts: 386
Variable a Focus Lens Sourcing
1

Does anyone know where I can source a variable focus lens to play with.  The ml-20-35, by optotune seems really interesting.  Edmund optics carries the electrical versions.   M12(s-mount) to c-mount to nex are readily available, but I can't seem to find anyone carrying the manual lens.

https://www.optotune.com/products/focus-tunable-lenses/manual-lens-ml-20-35

I think it would be interesting to play with because it seems to approximate human vision.  I'm really curious what happens when the focal length of a lens is changed without changing the distance.

Holger Bargen Veteran Member • Posts: 4,906
Re: Variable a Focus Lens Sourcing

SmoothOperator wrote:

Does anyone know where I can source a variable focus lens to play with. The ml-20-35, by optotune seems really interesting. Edmund optics carries the electrical versions. M12(s-mount) to c-mount to nex are readily available, but I can't seem to find anyone carrying the manual lens.

https://www.optotune.com/products/focus-tunable-lenses/manual-lens-ml-20-35

I think it would be interesting to play with because it seems to approximate human vision. I'm really curious what happens when the focal length of a lens is changed without changing the distance.

Sounds like a revolutionary new technolgy. If optical quality and durability of these lenses is good it could become a key fo a new generation of lenses.

Thank you for sharing!

Best regards

Holger

 Holger Bargen's gear list:Holger Bargen's gear list
Pentax K-5 Pentax K-S1 Pentax K-1 Pentax smc DA 55-300mm F4.0-5.8 ED Sigma 70mm F2.8 EX DG Macro +7 more
petrochemist Veteran Member • Posts: 3,619
Re: Variable a Focus Lens Sourcing

SmoothOperator wrote:

Does anyone know where I can source a variable focus lens to play with. The ml-20-35, by optotune seems really interesting. Edmund optics carries the electrical versions. M12(s-mount) to c-mount to nex are readily available, but I can't seem to find anyone carrying the manual lens.

https://www.optotune.com/products/focus-tunable-lenses/manual-lens-ml-20-35

I think it would be interesting to play with because it seems to approximate human vision. I'm really curious what happens when the focal length of a lens is changed without changing the distance.

Interesting but the last bit is pretty easy to predict. as you increase the focal length the bit thats focused will move away. The simple lens formula 1/F= 1/i + 1/s should apply

F = focal length, i = image distance (your keeping this fixed) s= subject distance ( the bit thats focused)

 petrochemist's gear list:petrochemist's gear list
Pentax K100D Sigma SD14 Pentax K-7 Panasonic Lumix DMC-GF2 Pentax Q +19 more
OP SmoothOperator Regular Member • Posts: 386
Re: Variable a Focus Lens Sourcing

petrochemist wrote:

SmoothOperator wrote:

Does anyone know where I can source a variable focus lens to play with. The ml-20-35, by optotune seems really interesting. Edmund optics carries the electrical versions. M12(s-mount) to c-mount to nex are readily available, but I can't seem to find anyone carrying the manual lens.

https://www.optotune.com/products/focus-tunable-lenses/manual-lens-ml-20-35

I think it would be interesting to play with because it seems to approximate human vision. I'm really curious what happens when the focal length of a lens is changed without changing the distance.

Interesting but the last bit is pretty easy to predict. as you increase the focal length the bit thats focused will move away. The simple lens formula 1/F= 1/i + 1/s should apply

F = focal length, i = image distance (your keeping this fixed) s= subject distance ( the bit thats focused)

That is the simple part, but what about image size, depth of field and such.  I suppose I could get some intuition by swapping in and out my 50mm macro and my 105mm enlarging lens.  My intuition from practicing with my eyes focusing on a finger close to my face, then far away is that the field of view doesn't really change.

OP SmoothOperator Regular Member • Posts: 386
Re: Variable a Focus Lens Sourcing

Holger Bargen wrote:

SmoothOperator wrote:

Does anyone know where I can source a variable focus lens to play with. The ml-20-35, by optotune seems really interesting. Edmund optics carries the electrical versions. M12(s-mount) to c-mount to nex are readily available, but I can't seem to find anyone carrying the manual lens.

https://www.optotune.com/products/focus-tunable-lenses/manual-lens-ml-20-35

I think it would be interesting to play with because it seems to approximate human vision. I'm really curious what happens when the focal length of a lens is changed without changing the distance.

Sounds like a revolutionary new technolgy. If optical quality and durability of these lenses is good it could become a key fo a new generation of lenses.

Thank you for sharing!

Best regards

Holger

I think someone should kickstart this.  I think combining a helicoid with a focus tunable lens would really be quite useful.  You wouldn't have to trade off between depth of field and working distance.  Though, it would probably only be feasible in the 35-80mm range due to conventional constraints like aperture and sensor size.

petrochemist Veteran Member • Posts: 3,619
Re: Variable a Focus Lens Sourcing

SmoothOperator wrote:

petrochemist wrote:

SmoothOperator wrote:

Does anyone know where I can source a variable focus lens to play with. The ml-20-35, by optotune seems really interesting. Edmund optics carries the electrical versions. M12(s-mount) to c-mount to nex are readily available, but I can't seem to find anyone carrying the manual lens.

https://www.optotune.com/products/focus-tunable-lenses/manual-lens-ml-20-35

I think it would be interesting to play with because it seems to approximate human vision. I'm really curious what happens when the focal length of a lens is changed without changing the distance.

Interesting but the last bit is pretty easy to predict. as you increase the focal length the bit thats focused will move away. The simple lens formula 1/F= 1/i + 1/s should apply

F = focal length, i = image distance (your keeping this fixed) s= subject distance ( the bit thats focused)

That is the simple part, but what about image size, depth of field and such. I suppose I could get some intuition by swapping in and out my 50mm macro and my 105mm enlarging lens. My intuition from practicing with my eyes focusing on a finger close to my face, then far away is that the field of view doesn't really change.

DOF and FOV will both be identical to a normal lens of the same focal length & the same degree of focus...

Things get more interesting when you pair one of these with another lens, to make a zoom, that can be retrofocus or telphoto...

 petrochemist's gear list:petrochemist's gear list
Pentax K100D Sigma SD14 Pentax K-7 Panasonic Lumix DMC-GF2 Pentax Q +19 more
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