Why doesn't Panasonic make a m 4/3rds speed booster for m 4/3 lenses?

Discussion in 'Accessories' started by Vantage-Point, May 17, 2017.

  1. Vantage-Point

    Vantage-Point New to Mu-43

    3
    Apr 15, 2017
    Hello everyone. I am new to this forum. I just recently bought a Panasonic GX85. I like the portability of the camera and lenses but like a lot of m 4/3 users, I wish the camera was more usable in low light. I see that some third party companies have focal reducers that adapt Canon and Nikon lenses (APS-C and Full Frame lenses) to the m 4/3 mount. This makes for a bulky setup . If Panasonic made a focal reducer (speed booster) that allows m 4/3 lenses to act like like a Full Frame lens (add 2 stops of light) I'm sure it would sell well, sell more m 4/3 lenses, and attract more people to m 4/3rds. Some features I would like to see it have are: A weather resistant body. It must be compatible with the high speed focus systems of Panasonic (DFD, contrast and phase based focusing) and Olympus. It needs to work with body and lens image stabilization. Hopefully something like this could be mass produced for between $350 to $500 USD. What do you think?
     
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  2. Andym72

    Andym72 Mu-43 Veteran

    346
    Mar 4, 2013
    Reading, UK
    Because speedboosters aka focal reducers need the lens being adapted to throw a larger image circle that is needed by the m43 sensor and then what the focal reducer does is reduce the size of this image circle down to the size of the m43 sensor, and as a consequence the same amount of light is squashed into a smaller area, resulting in more light per unit area on the sensor. Usually a 1.4x focal reducer will increase the effective max aperture of the adapted lens by 1 stop - a 1 stop larger lens aperture has twice the area, and since the area of a circle is proportional to the radius of the circle squared, the radius of a 1 stop larger aperture has increased by √2, which is approx 1.4. So you see, that is how the value of 1.4 is related to 1 stop more light.
     
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  3. Linden

    Linden Mu-43 Regular

    28
    May 1, 2017
    Knox, TN
    I think this is pure physics. Full frame and APS-C lenses have larger projected image circles for larger sensors, so the speed boosters essentially act like a magnifying glass to focus this light onto the smaller m4/3 sensor. As a result you get a higher intensity of light in a smaller area (like using a magnifying glass to start a fire, for example).

    You can't make a m4/3 speed booster for m4/3 lenses because they're already made for that specific sensor size (one reason the lenses are so small and light). There's no "excess light" transmitted by the lens to concentrate into a smaller area.
     
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  4. Phocal

    Phocal Mu-43 Hall of Famer

    Jan 3, 2014
    Ok............so...............................um.......................................there are lenses in the m4/3 mount from f0.95 to f6.7............what focal length is there not a fast lens available that you want?
     
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  5. Linden

    Linden Mu-43 Regular

    28
    May 1, 2017
    Knox, TN
    I agree. A FF lens + speed booster is just a bulky option vs buying a fast native lens, unless a needed option doesn't exist natively for whatever reason.

    Perhaps the thought was that for $350-500 we could just boost all of our native (cheap, slow) lenses and therefore not need to pay the big $$$ for fast glass. It sounds good in theory, but it's impossible based on physics and there's also zero incentive for a manufacturer to make one (if it were possible) and negate much of the need for its own line of premium glass.
     
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  6. Carbonman

    Carbonman Mu-43 All-Pro Subscribing Member

    Jul 10, 2014
    Vancouver BC
    Graham
    Add to the above comments; Panasonic only made a small handful of different 4/3rds lenses. It doesn't make sense for them to support such a small market when you can buy a 4/3rds to m4/3rds adapter from Olympus. Both Panasonic and Olympus want the old product lines completely out of their business streams so they can concentrate on selling the product rolling out of their factories right now.
     
  7. Phocal

    Phocal Mu-43 Hall of Famer

    Jan 3, 2014
    They are only talking about m4/3 lenses, the m is separated by a space in their post. I made that mistake when I first read it also. They want a way to speedboost m4/3 lenses on a m4/3 camera so they don't have to buy fast glass, just an adapter that makes all the lenses fast.
     
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  8. Vantage-Point

    Vantage-Point New to Mu-43

    3
    Apr 15, 2017
    I do own fast glass. I currently have the Panasonic 12-35 mm f2.8, 35-100mm F2.8 , 15 mmF1.7, 25 mm f1.7, and the42.5 mm F1.7. I was just wondering if a speed booster could be made for m4/3 lenses to allow for lower isos in low light.
     
  9. tino84

    tino84 Mu-43 Veteran

    241
    Dec 29, 2013
    Why would panasonic and olympus build such a thing for a native mount instead of make a fast glass directly? You can buy a 42,5 1.2 and have no more problems of high ISO.
     
  10. tkbslc

    tkbslc Mu-43 Hall of Famer

    No.

    For a speed booster to be possible, you need 2 things:

    1) A larger imaging circle. The speed booster works by using special optics to squeeze a larger imaging circle from the lens onto a sensor designed for a smaller one. 4/3 and m4/3 lenses have 2x crop imaging circles, so there's no extra image to gain. So we already strike out/

    2) You need room to fit the speed booster in the light path without interfering with the original mount depth. If the speed booster increases the distance between the lens and the sensor, you lose infinity focus. That's exactly how macro extension tubes work. This is why you can never see a speed booster designed to mount native lenses to the original mount. There's no room.
     
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  11. Klorenzo

    Klorenzo Mu-43 All-Pro

    Mar 10, 2014
    Lorenzo
    I think a properly designed booster may solve this problem. There are adapters, with optical elements, allowing to mount lenses at a larger flange distance than the one they were designed for (keeping full focus functionality).
    But I'm not sure if these adapters alter the focal length or the lens speed in any way fundamentally not compatible with the speed booster function.


    As a side note a m43 -> m43 to speed-booster cannot exist for a simple abstract reasoning: if these were possible, I could stack as many boosters as I want to gain extra stops at each step. So eventually one should start to wonder: where exactly is this extra light coming from?
     
    Last edited: May 18, 2017
  12. tkbslc

    tkbslc Mu-43 Hall of Famer

    Those adapters work by adding a teleconverter element. For example Canon FD to EF adapter has a 1.2x teleconverter. Obviously if you add a TC and a speed booster together, you are basically back where you started!
     
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  13. Petrochemist

    Petrochemist Mu-43 Top Veteran

    717
    Mar 21, 2013
    N Essex, UK
    Mike
    No 2 is worse than you're making out. To use a focal reducer the lens has to be CLOSER to the sensor than it does without the optics. My EOS based reducer mounts the lens ~19mm further away the the MFT mounting, with a standard adapter thats nearer 23mm, so the optics with the 0.71x reducer I have need the lens ~4mm closer in.
    To use a similar reducer on a MFT lens the lens would have to sit ~4mm inside the lens mount with the reducer optics closer still.
    I suspect if additional relay lenses are used this problem could be solved t the cost of an inverted image & greatercomplexity/abberations. Even then the coverage issue would still remain.
     
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  14. Drdave944

    Drdave944 Mu-43 Top Veteran Subscribing Member

    939
    Feb 2, 2012
    Canon has mirrorless cameras and special M lenses to put on them. What if you want to use their other glass? Presto! You can buy an adapter that maintains all the functions of the glass,such as autofocus and IS. It is an APS-C size picture which is cropped . It does not change the focal length or F stop. It gives users an incentive to use their M-Cameras,which are very basic units,but are quite nice. So ,unless there is a financial incentive,don't hold your breath.
     
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  15. tkbslc

    tkbslc Mu-43 Hall of Famer

    Metabones lets you do that with Canon to most mirrorless systems
     
  16. pdk42

    pdk42 One of the "Eh?" team

    Jan 11, 2013
    Leamington Spa, UK
    Yeah, come on Panasonic - that's just what we all need! I'd buy one for sure. Two in fact - then stack them and make my lenses 2-stops faster.

    Hell, why not three or four and go for broke!! In fact, if I keep adding these adapters then there'd be a point at which I'd melt the sensor with the light intensity. Maybe that's why they don't make them - can you imagine the health and safety issues with devices like that? They could start forest fires, or even initiate thermonuclear reactions. Yeah, I guess that's why Panasonic don't make them. Smart people those engineers.
     
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  17. pellicle

    pellicle Mu-43 Hall of Famer

    Feb 10, 2010
    Southport, OzTrailEYa
    pellicle
    Hi

    The answer is no, because (as answered neatly above):

    Perpetual motion machines are constrained by the same physics
     
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  18. callie

    callie Mu-43 Regular

    46
    Oct 28, 2016
    Eddie
    I seems that the description/Purpose of the 'Speed booster' is somehow not understood.
     
  19. Clint

    Clint Mu-43 All-Pro Subscribing Member

    Apr 22, 2013
    San Diego area, CA
    Clint
    Don't wish for "the camera was more usable in low light." They are very useable in low light. And if you want to shoot in very dim light, there are over two dozen lenses from f/0.95 - f/2.0.
     
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  20. Linden

    Linden Mu-43 Regular

    28
    May 1, 2017
    Knox, TN
    Exactly. Just think of them as lenses with built-in speed boosters. :biggrin:
     
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