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09-05-2017, 11:46 PM   #16
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QuoteOriginally posted by 6BQ5 Quote
So, mounting a 50mm f/1.4 lens on this adapter will give me an optic system that works like a 25mm f/0.7. Apply the Q7 crop factor of 4.7x I will have an image that is equivalent to a 117.5mm lens on FF showing a depth of field as if that 117.5mm lens was set to f/3.29?
There is an easier way to look at this:

If the Q7 has a sensor format factor of x4,7 and this Speed Bosster has x0,5 then it effectively halves the format factor into x2,35.
Remember 1 inch sensor is x2,7 (think RX100 or Nikon 1). MFT is x2.
So the light gathering/noise/DoF characteristics of your Q now are better than those of a 1" camera and closer to a mFT camera.

Since you are facing x0,5 less magnification of lens faults, you'll see things like CA's also reduced by half. Similar to a teleconverter magnifying lens weaknesses a good quality wide angle converter can reduce them.

09-06-2017, 06:02 AM   #17
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Everything about this is weird:
  • The name is weird; it's silly and might even offend people of faith.
  • The timing is weird; the Q system "peaked" long ago - MS Optics launched a native Q-mount lens in 2012. It's also not april 1...
  • The mixing of brands is weird; a K to Q or Nikon F to Nikon 1 focal reducer would make a lot more sense (I don't know if the Nikon 1 has enough room; the flange focal distance is much greater). Remarkably, Metabones still haven't made a K to Sony E/Fuji X/MFT focal reducer.
In summary, this is weird.

I want one.

Last edited by Jens Lyn IV; 09-06-2017 at 06:15 AM.
09-06-2017, 06:41 AM   #18
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QuoteOriginally posted by beholder3 Quote
There is an easier way to look at this:

If the Q7 has a sensor format factor of x4,7 and this Speed Bosster has x0,5 then it effectively halves the format factor into x2,35.
Remember 1 inch sensor is x2,7 (think RX100 or Nikon 1). MFT is x2.
So the light gathering/noise/DoF characteristics of your Q now are better than those of a 1" camera and closer to a mFT camera.

Since you are facing x0,5 less magnification of lens faults, you'll see things like CA's also reduced by half. Similar to a teleconverter magnifying lens weaknesses a good quality wide angle converter can reduce them.
Thanks for this explanation. This helps. This could be a fun little gadget to experiment with and potentially breathe some new life into current lenses, fast, prime lenses. Perhaps the FA Limited lenses would be the most interesting to try. I'm not sure how much value a zoom lens will have here.

I don't have any Nikon lenses and I don't want to buy any so I'll pass on this one. Hopefully the K->Q version comes out soon.
09-06-2017, 07:03 AM   #19
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QuoteOriginally posted by 6BQ5 Quote
Can someone clarify what this adapter does? Does it reduce the crop factor of the Q by half? Why would my Q suddenly become a low light monster as the press release states?
It's a telecompressor, which is pretty common for M43 and APS-C sensor mirrorless cameras.

Telecompressor - Wikipedia

For example, I have a Mitakon Lens Turbo II with a 0.726x crop factor, that accepts full-frame K mount lenses and adapts them onto a Sony APS-C mirrorless with a 1.5x crop factor. I usually couple this with my FA43Ltd, and I get a combo that is "close enough" to a true normal:
- the effective focal length is 43*0.726*1.5 ~= 47(mm);
- effective aperture in terms of light gathering ability is 1.9*0.726 ~= 1.4;
- the max aperture in terms of DOF is 1.9*0.726*1.5 ~= 2.0.

So I basically gets a lens that has a 47mm FOV, has the light gathering ability of 1.4, and has similar bokeh and DOF of 2.0 wide open.

09-06-2017, 07:12 AM - 2 Likes   #20
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QuoteOriginally posted by dcshooter Quote
Seriously, though, it says right there in the press release that they are making one for K lenses:

"Planned lens mounts for the Speed Booster Q666 include a Pentax-K version and a Nikon F/G version with the most advanced Nikon G aperture adjustment mechanism in the industry."

The Nikon is featured because there are way more Nikon lenses in production/being sold right now, simple as that.

I also don't understand why people here constantly complain that third party manufacturers aren't doing anything for Pentax, then slag them when they actually do.

Yeah, it's a niche product, but no one is forcing you to buy it.
I suspect that they are going with Nikon G first because they need an F1.2 lens to reduce to a record-breaking F 0.666. Is there a K-mount F1.2? I have a Takumar 50/1.4. Sadly, I don't have a Nikon F1.2 and not likely to buy one for this application. Nor are owners of a Nikon F1.2 likely to buy a Q and this SpeedBooster to see in the dark.

It's still ridiculous though. I can count on one hand the number of people that wanted to turn the Q into a low light, shallow DOF beast, and that's being generous. And I still want it if only for the fact that in ten years time I'll be one of only 20 people in the whole world that has one!
09-06-2017, 07:22 AM - 1 Like   #21
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QuoteOriginally posted by johnmflores Quote
Is there a K-mount F1.2?
Yes. K&A 50mm f/1.2
09-06-2017, 07:28 AM - 1 Like   #22
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Plus Kerlee 35mm f/1.2 and Mitakon Speedmaster 85mm f/1.2.
09-06-2017, 10:54 AM   #23
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Revuenon 55mm f/1.2 here.

Btw excellent lens, equal to K&A f/1.2 in every aspect except:
a) minimum focusing distance is a little bit longer
b) rendering backlights wide open @f/1.2


Last edited by banep; 09-06-2017 at 11:05 AM.
09-06-2017, 10:59 AM   #24
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QuoteOriginally posted by Kunzite Quote
Yes. K&A 50mm f/1.2
QuoteOriginally posted by Mistral75 Quote
Plus Kerlee 35mm f/1.2 and Mitakon Speedmaster 85mm f/1.2.
QuoteOriginally posted by banep Quote
Revuenon 55mm f/1.2 here.
Btw excellent lens.
Thanks. This makes support for the Nikon mount even more puzzling...maybe simply because its so easy to do?
09-06-2017, 11:02 AM - 2 Likes   #25
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QuoteOriginally posted by johnmflores Quote
Thanks. This makes support for the Nikon mount even more puzzling...maybe simply because its so easy to do?
According to the extremely competent Mr. Kazuto Yamaki, Sigma's CEO, a mount using a physical aperture lever is mind blowing rocket science and makes building lenses and adapter sooooo complex, it is prohibitive.
09-06-2017, 11:50 AM   #26
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QuoteOriginally posted by dcshooter Quote
simple as that.
It would be simpler to appeal to the people who actually own a Q body FIRST!.....so they say a K mount is coming,YES...theres another corporation that says that too and WHEN?...

---------- Post added 09-07-17 at 05:54 AM ----------

QuoteOriginally posted by Jens Lyn IV Quote
In summary, this is weird.
Yes, i agree...goes against logic....i wonder when the adapter for the Samsung NX mount is being done?
09-06-2017, 12:02 PM   #27
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QuoteOriginally posted by johnmflores Quote
Thanks. This makes support for the Nikon mount even more puzzling...maybe simply because its so easy to do?
Probably because Metabones propose several adapters for Nikon F "G" lenses and none for Pentax K mount lenses . The Nikon part of the Speed Booster was therefore 'off the shelf' for them whilst the Pentax K part had to be designed.
09-06-2017, 12:05 PM   #28
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QuoteOriginally posted by johnmflores Quote
I have a Takumar 50/1.4. Sadly
Many who have tried that lens with a speedbooster have reported that the rear element collides, so its unuseable....i use the Tak 55mmf1.8....works fine.
09-06-2017, 12:08 PM   #29
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QuoteOriginally posted by Mistral75 Quote
Probably because Metabones propose several adapters for Nikon F "G" lenses and none for Pentax K mount lenses . The Nikon part of the Speed Booster was therefore 'off the shelf' for them whilst the Pentax K part had to be designed.
Makes sense. Maybe that means that a K to M43 Speed Booster will be in the pipeline too...
09-06-2017, 12:13 PM   #30
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QuoteOriginally posted by dcshooter Quote
it's a niche product, but no one is forcing you to buy it.
Its a EXTREME niche product ...Pentax is a niche brand,Qs are a niche product within a niche brand....When/IF it gets to K mount,its takes nicheness to a new level!
QuoteOriginally posted by johnmflores Quote
And I still want it if only for the fact that in ten years time I'll be one of only 20 people in the whole world that has one!
Twenty is being generous!

---------- Post added 09-07-17 at 06:24 AM ----------

QuoteOriginally posted by johnmflores Quote
a K to M43 Speed Booster
Just put a EF mount on any lens ....there are cheap FR/SBs all over ebay....the ZHongi brand is a third the price of metabones and has similar performance.
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