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11-14-2020, 04:10 AM - 1 Like   #271
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QuoteOriginally posted by Not a Number Quote
It is only a KA mount from my understanding, no chip. How many pins does it have on the mount? Post some pictures?


11-14-2020, 04:57 AM   #272
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QuoteOriginally posted by Not a Number Quote
Sweet! I wonder if it will be KA mount with contacts?
3. Automatic Aperture Coupling Lever for Pentax K
Laowa 100mm f/2.8 2x Ultra Macro APO in Pentax-K mount is assembled with the automatic aperture coupling lever, which allows aperture control via the body of the camera. Users can either use the manual aperture ring or park the focusing ring at the “A” symbol and adjust the aperture via the camera. Exif data would be stored in the metadata as well.

Read more: Venus Optics to announce a new Laowa 100mm f/2.8 2X Ultra Macro APO lens for Pentax K-mount - Pentax Rumors
11-14-2020, 04:55 PM - 4 Likes   #273
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OK, a few thoughts and shots from my upcoming write-up.

- The lens has some handling quirks. For example, there's no pin to lock the A position in place and the aperture ring clicks are very, very low friction. So it's super easy to knock the lens out of the A position while trying to compose and focus a shot in the field. Then the camera doesn't fire at all, which is pretty annoying. But once you know the risk, you can adjust the way you hold the lens.

- The mount aperture control is definitely at the KA level rather than KAF. If you look at this wonderful PF page on the evolution of the K-mount, you'll find the "Digital information contact" which was added with the KAF mount in 1989. AFAIK, this is the contact which a lens uses to communicate its focal length to the body, and it's definitely not present on the Laowa (see image below, or the one posted previously by Mistral75). And as mentioned previously, your K-Mount body will prompt you for a focal length when you turn it on with the Laowa 100mm 2X mounted.

- Optically, after just a few tests, I believe this lens doesn't take many prisoners. I need to retest at 2:1, where it's exceedingly difficult to control for correct focus if you don't have a good focus rail. (For example, when shooting a penny you can find once you review your shots that the bottom of the penny is in focus, but the top of the engraved letters on the penny are not! In the field, if the eyes are not in focus, the shot is just left on the cutting room floor so to speak, but in testing, you need to nail it.) But otherwise, testing against the D-FA 100mm WR and looking both at portrait-type shots shooting very open at around 1m distance, and at 1:1 macro shots shot very closed, I am very impressed.

- I shot about 400 frames in the field over three outings, and have published nine images as a result of those outings. You can have a look at all of them in this Flickr album. Now it definitely will no longer be possible to shoot bugs until the spring...






11-14-2020, 05:05 PM   #274
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It surprises me that these 3rd party lens manufacturers that obviously display a high degree of sophistication in lens design and manufacture cannot incorporate the most basic level of electronic coupling corresponding to the technology of 30 years ago.

11-14-2020, 05:07 PM   #275
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QuoteOriginally posted by Doundounba Quote
OK, a few thoughts and shots from my upcoming write-up.

- The lens has some handling quirks. For example, there's no pin to lock the A position in place and the aperture ring clicks are very, very low friction. So it's super easy to knock the lens out of the A position while trying to compose and focus a shot in the field. Then the camera doesn't fire at all, which is pretty annoying. But once you know the risk, you can adjust the way you hold the lens.

- The mount aperture control is definitely at the KA level rather than KAF. If you look at this wonderful PF page on the evolution of the K-mount, you'll find the "Digital information contact" which was added with the KAF mount in 1989. AFAIK, this is the contact which a lens uses to communicate its focal length to the body, and it's definitely not present on the Laowa (see image below, or the one posted previously by Mistral75). And as mentioned previously, your K-Mount body will prompt you for a focal length when you turn it on with the Laowa 100mm 2X mounted.

- Optically, after just a few tests, I believe this lens doesn't take many prisoners. I need to retest at 2:1, where it's exceedingly difficult to control for correct focus if you don't have a good focus rail. (For example, when shooting a penny you can find once you review your shots that the bottom of the penny is in focus, but the top of the engraved letters on the penny are not! In the field, if the eyes are not in focus, the shot is just left on the cutting room floor so to speak, but in testing, you need to nail it.) But otherwise, testing against the D-FA 100mm WR and looking both at portrait-type shots shooting very open at around 1m distance, and at 1:1 macro shots shot very closed, I am very impressed.

- I shot about 400 frames in the field over three outings, and have published nine images as a result of those outings. You can have a look at all of them in this Flickr album. Now it definitely will no longer be possible to shoot bugs until the spring...





I am definitely looking forward to a full review of this.
11-14-2020, 06:02 PM - 2 Likes   #276
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QuoteOriginally posted by Paul the Sunman Quote
It surprises me that these 3rd party lens manufacturers that obviously display a high degree of sophistication in lens design and manufacture cannot incorporate the most basic level of electronic coupling corresponding to the technology of 30 years ago.
They would need to do a different design for each and small brands would be even less likey to get lenses.
11-14-2020, 06:56 PM   #277
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QuoteOriginally posted by UncleVanya Quote
They would need to do a different design for each and small brands would be even less likey to get lenses.
Indeed. For me the solution adopted by Laowa makes sense from a cost perspective, especially since the focal length and max aperture are perfectly standard values here. I don't mind giving the focal length when I turn on the camera, and the max aperture is encoded in the pins. If asked to choose, I'd prefer a locking A position over a chip that tells the camera the focal length...
11-14-2020, 07:22 PM - 1 Like   #278
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So except for the lack of a lock the mount is pretty much a throwback to the 80-90s KA mount with the insulated plugs.

You really have to be in awe of Thomas Shahan as he is doing handheld focus stacking shots.

11-15-2020, 05:15 AM   #279
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QuoteOriginally posted by Doundounba Quote
Indeed. For me the solution adopted by Laowa makes sense from a cost perspective, especially since the focal length and max aperture are perfectly standard values here. I don't mind giving the focal length when I turn on the camera, and the max aperture is encoded in the pins. If asked to choose, I'd prefer a locking A position over a chip that tells the camera the focal length...
I also really prefer a simple A-Implementation over the semi-correct IRIX one, which doesn't work with most extension rings and neither with the DA teleconverter. @Doundounba, I'd be interested if they got the lever angle to aperture relation right, i.e. if exposure at different F-Stops is reasonably consistent.
11-15-2020, 06:47 AM   #280
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My dilemma D-FA 100mm WR vs Irix 150mm is now even more confusing as I have this option.
11-15-2020, 07:24 AM   #281
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I often shoot with the Canon MP-E65mm hand held and as long as you have a good lighting setup you can get away with quite a bit. you have to watch out for diffraction after about f/8 though. Looking forward to getting the Laowa, it's not yet available in UK shops though.


Hover Fly
by Mike.Pursey, on Flickr


Fly Macro
by Mike.Pursey, on Flickr
11-15-2020, 12:04 PM   #282
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QuoteOriginally posted by Mike.P® Quote
I often shoot with the Canon MP-E65mm hand held and as long as you have a good lighting setup you can get away with quite a bit. you have to watch out for diffraction after about f/8 though. Looking forward to getting the Laowa, it's not yet available in UK shops though.


Hover Fly
by Mike.Pursey, on Flickr


Fly Macro
by Mike.Pursey, on Flickr
Both nice, but that second one's great!
11-15-2020, 02:50 PM   #283
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QuoteOriginally posted by Paul the Sunman Quote
It surprises me that these 3rd party lens manufacturers that obviously display a high degree of sophistication in lens design and manufacture cannot incorporate the most basic level of electronic coupling corresponding to the technology of 30 years ago.
Simple: patents. KA mount patents have expired. Not true for KAF: KA2, KAF2, KAF3 and KAF4 (AFAICT).
11-15-2020, 02:54 PM   #284
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I'll post some sample images when mine arrives.
11-15-2020, 03:29 PM   #285
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QuoteOriginally posted by thibs Quote
Simple: patents. KA mount patents have expired. Not true for KAF: KA2, KAF2, KAF3 and KAF4 (AFAICT).
In most countries patent validity / protection is 20 years from the day of filing the patent request.

KAF (1987) has been in the public domain since more than a decade. KAF includes basic lens-body digital transmission: lens focal length, distance to subject, selected f-stop and other information.

Venus Optics would have been entitled to use KAF / KA2 (which is KAF less AF) protocols for their Laowa 100mm f/2.8 2x Ultra Macro Apo, should have they wished to do so.
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