Pentax glass on m4/3: weird behavior
Hello gang, I've just tried a few Pentax lenses on my Panny GF-1 (via K-micro4/3 adapter), just to find a weird behaviour. With close subjects (inches to meters), the actual distance of my subject (properly focused by looking at magnified LCD) can be similar to that one indicated on the distance scale of the lens. However, when trying to properly focus at infinity I have to set a much closer distance on the lens ring, with larger and larger offsets as focal legths shorten. Examples: 100mm lens focused at infinity -> focusing ring is set at 15-20m; 50mm lens focused at infinity -> focusing ring is set at 7-10m; 28mm lens focused at infinity -> focusing ring is set at 3m! With a Samyang 8mm fisheye, there's no way to focus (lens helicoid has no run enough to find focus). It happens that by setting the focus at its minimum focus distance, the lens is almost (but not yet) focused at infinity. By approaching the subject, things become worse. Have you ever seen anything like that? How would you explain that? Wrong adapter? Too short to set proper register distance for K-bayonet lenses? Cheers, Dario -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Pentax glass on m4/3: weird behavior
I'd like to hear this myself. What brand of adaptor? On Tue, Mar 15, 2011 at 6:02 PM, Dario Bonazza wrote: > Hello gang, > > I've just tried a few Pentax lenses on my Panny GF-1 (via K-micro4/3 > adapter), just to find a weird behaviour. > > With close subjects (inches to meters), the actual distance of my subject > (properly focused by looking at magnified LCD) can be similar to that one > indicated on the distance scale of the lens. However, when trying to > properly focus at infinity I have to set a much closer distance on the lens > ring, with larger and larger offsets as focal legths shorten. > > Examples: > 100mm lens focused at infinity -> focusing ring is set at 15-20m; > 50mm lens focused at infinity -> focusing ring is set at 7-10m; > 28mm lens focused at infinity -> focusing ring is set at 3m! > > With a Samyang 8mm fisheye, there's no way to focus (lens helicoid has no > run enough to find focus). It happens that by setting the focus at its > minimum focus distance, the lens is almost (but not yet) focused at > infinity. By approaching the subject, things become worse. > > Have you ever seen anything like that? How would you explain that? Wrong > adapter? Too short to set proper register distance for K-bayonet lenses? > > Cheers, > > Dario > > -- > PDML Pentax-Discuss Mail List > PDML@pdml.net > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and > follow the directions. > -- Steve Desjardins -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Pentax glass on m4/3: weird behavior
No name on it, found in ebay from Hong Kong. I bought it some time ago, but I can no longer find trace of that auction. However, it could be this one: http://cgi.ebay.com/Pentax-PK-K-lens-Micro-4-3-Adapter-EP-1-GF1-G1-GH1-/250630349531?pt=Lens_Accessories&hash=item3a5abba2db Dario - Original Message - From: "Steven Desjardins" To: "Pentax-Discuss Mail List" Sent: Tuesday, March 15, 2011 11:53 PM Subject: Re: Pentax glass on m4/3: weird behavior I'd like to hear this myself. What brand of adaptor? On Tue, Mar 15, 2011 at 6:02 PM, Dario Bonazza wrote: Hello gang, I've just tried a few Pentax lenses on my Panny GF-1 (via K-micro4/3 adapter), just to find a weird behaviour. With close subjects (inches to meters), the actual distance of my subject (properly focused by looking at magnified LCD) can be similar to that one indicated on the distance scale of the lens. However, when trying to properly focus at infinity I have to set a much closer distance on the lens ring, with larger and larger offsets as focal legths shorten. Examples: 100mm lens focused at infinity -> focusing ring is set at 15-20m; 50mm lens focused at infinity -> focusing ring is set at 7-10m; 28mm lens focused at infinity -> focusing ring is set at 3m! With a Samyang 8mm fisheye, there's no way to focus (lens helicoid has no run enough to find focus). It happens that by setting the focus at its minimum focus distance, the lens is almost (but not yet) focused at infinity. By approaching the subject, things become worse. Have you ever seen anything like that? How would you explain that? Wrong adapter? Too short to set proper register distance for K-bayonet lenses? Cheers, Dario -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Pentax glass on m4/3: weird behavior
sounds like the adapter is not long/thick enough for proper infinity registration. -- J.C. O'Connell (mailto:hifis...@gate.net) Join the CD PLAYER & DISC Discussions : http://tech.groups.yahoo.com/group/cdplayers/ http://launch.groups.yahoo.com/group/cdsound/ -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Steven Desjardins Sent: Tuesday, March 15, 2011 6:54 PM To: Pentax-Discuss Mail List Subject: Re: Pentax glass on m4/3: weird behavior I'd like to hear this myself. What brand of adaptor? On Tue, Mar 15, 2011 at 6:02 PM, Dario Bonazza wrote: > Hello gang, > > I've just tried a few Pentax lenses on my Panny GF-1 (via K-micro4/3 > adapter), just to find a weird behaviour. > > With close subjects (inches to meters), the actual distance of my > subject (properly focused by looking at magnified LCD) can be similar > to that one indicated on the distance scale of the lens. However, when > trying to properly focus at infinity I have to set a much closer > distance on the lens ring, with larger and larger offsets as focal > legths shorten. > > Examples: > 100mm lens focused at infinity -> focusing ring is set at 15-20m; 50mm > lens focused at infinity -> focusing ring is set at 7-10m; 28mm lens > focused at infinity -> focusing ring is set at 3m! > > With a Samyang 8mm fisheye, there's no way to focus (lens helicoid has > no run enough to find focus). It happens that by setting the focus at > its minimum focus distance, the lens is almost (but not yet) focused > at infinity. By approaching the subject, things become worse. > > Have you ever seen anything like that? How would you explain that? > Wrong adapter? Too short to set proper register distance for K-bayonet > lenses? > > Cheers, > > Dario > > -- > PDML Pentax-Discuss Mail List > PDML@pdml.net > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and > follow the directions. > -- Steve Desjardins -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Pentax glass on m4/3: weird behavior
It sounds to me that you're adapter doesn't supply the proper flange distance. Maybe it doesn't even keep the planes parallel. On 3/15/2011 6:02 PM, Dario Bonazza wrote: Hello gang, I've just tried a few Pentax lenses on my Panny GF-1 (via K-micro4/3 adapter), just to find a weird behaviour. With close subjects (inches to meters), the actual distance of my subject (properly focused by looking at magnified LCD) can be similar to that one indicated on the distance scale of the lens. However, when trying to properly focus at infinity I have to set a much closer distance on the lens ring, with larger and larger offsets as focal legths shorten. Examples: 100mm lens focused at infinity -> focusing ring is set at 15-20m; 50mm lens focused at infinity -> focusing ring is set at 7-10m; 28mm lens focused at infinity -> focusing ring is set at 3m! With a Samyang 8mm fisheye, there's no way to focus (lens helicoid has no run enough to find focus). It happens that by setting the focus at its minimum focus distance, the lens is almost (but not yet) focused at infinity. By approaching the subject, things become worse. Have you ever seen anything like that? How would you explain that? Wrong adapter? Too short to set proper register distance for K-bayonet lenses? Cheers, Dario -- Where's the Kaboom? There was supposed to be an Earth-shattering Kaboom! --Marvin the Martian. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Pentax glass on m4/3: weird behavior
Let's do some math: K bayonet register = 45.46mm m4/3 register = 19.25mm Then K-m4/3 adaptor must be 45.46 - 19.25 = 26.21mm A caliper reads 25.85mm for my adaptor. Hence it looks like being 0.35mm short. Is that enough for such a weird behaviour? Dario - Original Message - From: "Dario Bonazza" To: "Pentax-Discuss Mail List" Sent: Wednesday, March 16, 2011 12:41 AM Subject: Re: Pentax glass on m4/3: weird behavior No name on it, found in ebay from Hong Kong. I bought it some time ago, but I can no longer find trace of that auction. However, it could be this one: http://cgi.ebay.com/Pentax-PK-K-lens-Micro-4-3-Adapter-EP-1-GF1-G1-GH1-/250630349531?pt=Lens_Accessories&hash=item3a5abba2db Dario - Original Message - From: "Steven Desjardins" To: "Pentax-Discuss Mail List" Sent: Tuesday, March 15, 2011 11:53 PM Subject: Re: Pentax glass on m4/3: weird behavior I'd like to hear this myself. What brand of adaptor? On Tue, Mar 15, 2011 at 6:02 PM, Dario Bonazza wrote: Hello gang, I've just tried a few Pentax lenses on my Panny GF-1 (via K-micro4/3 adapter), just to find a weird behaviour. With close subjects (inches to meters), the actual distance of my subject (properly focused by looking at magnified LCD) can be similar to that one indicated on the distance scale of the lens. However, when trying to properly focus at infinity I have to set a much closer distance on the lens ring, with larger and larger offsets as focal legths shorten. Examples: 100mm lens focused at infinity -> focusing ring is set at 15-20m; 50mm lens focused at infinity -> focusing ring is set at 7-10m; 28mm lens focused at infinity -> focusing ring is set at 3m! With a Samyang 8mm fisheye, there's no way to focus (lens helicoid has no run enough to find focus). It happens that by setting the focus at its minimum focus distance, the lens is almost (but not yet) focused at infinity. By approaching the subject, things become worse. Have you ever seen anything like that? How would you explain that? Wrong adapter? Too short to set proper register distance for K-bayonet lenses? Cheers, Dario -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. - Nessun virus nel messaggio. Controllato da AVG - www.avg.com Versione: 10.0.1204 / Database dei virus: 1498/3507 - Data di rilascio: 14/03/2011 -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
RE: Pentax glass on m4/3: weird behavior
seems like it would have to be off by more than 0.36mm for the results your getting, something doesn't add up. -- J.C. O'Connell (mailto:hifis...@gate.net) Join the CD PLAYER & DISC Discussions : http://tech.groups.yahoo.com/group/cdplayers/ http://launch.groups.yahoo.com/group/cdsound/ -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Dario Bonazza Sent: Tuesday, March 15, 2011 8:05 PM To: Pentax-Discuss Mail List Subject: Re: Pentax glass on m4/3: weird behavior Let's do some math: K bayonet register = 45.46mm m4/3 register = 19.25mm Then K-m4/3 adaptor must be 45.46 - 19.25 = 26.21mm A caliper reads 25.85mm for my adaptor. Hence it looks like being 0.35mm short. Is that enough for such a weird behaviour? Dario - Original Message - From: "Dario Bonazza" To: "Pentax-Discuss Mail List" Sent: Wednesday, March 16, 2011 12:41 AM Subject: Re: Pentax glass on m4/3: weird behavior > No name on it, found in ebay from Hong Kong. I bought it some time > ago, > but I can no longer find trace of that auction. However, it could be this > one: > http://cgi.ebay.com/Pentax-PK-K-lens-Micro-4-3-Adapter-EP-1-GF1-G1-GH1-/2506 30349531?pt=Lens_Accessories&hash=item3a5abba2db > > Dario > > - Original Message - > From: "Steven Desjardins" > To: "Pentax-Discuss Mail List" > Sent: Tuesday, March 15, 2011 11:53 PM > Subject: Re: Pentax glass on m4/3: weird behavior > > >> I'd like to hear this myself. What brand of adaptor? >> >> On Tue, Mar 15, 2011 at 6:02 PM, Dario Bonazza >> wrote: >>> Hello gang, >>> >>> I've just tried a few Pentax lenses on my Panny GF-1 (via K-micro4/3 >>> adapter), just to find a weird behaviour. >>> >>> With close subjects (inches to meters), the actual distance of my >>> subject >>> (properly focused by looking at magnified LCD) can be similar to that >>> one >>> indicated on the distance scale of the lens. However, when trying to >>> properly focus at infinity I have to set a much closer distance on the >>> lens >>> ring, with larger and larger offsets as focal legths shorten. >>> >>> Examples: >>> 100mm lens focused at infinity -> focusing ring is set at 15-20m; >>> 50mm lens focused at infinity -> focusing ring is set at 7-10m; 28mm >>> lens focused at infinity -> focusing ring is set at 3m! >>> >>> With a Samyang 8mm fisheye, there's no way to focus (lens helicoid >>> has >>> no >>> run enough to find focus). It happens that by setting the focus at its >>> minimum focus distance, the lens is almost (but not yet) focused at >>> infinity. By approaching the subject, things become worse. >>> >>> Have you ever seen anything like that? How would you explain that? >>> Wrong adapter? Too short to set proper register distance for >>> K-bayonet lenses? >>> >>> Cheers, >>> >>> Dario > > > -- > PDML Pentax-Discuss Mail List > PDML@pdml.net > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and > follow the directions. > > > - > Nessun virus nel messaggio. > Controllato da AVG - www.avg.com > Versione: 10.0.1204 / Database dei virus: 1498/3507 - Data di > rilascio: > 14/03/2011 > -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Pentax glass on m4/3: weird behavior
The Novoflex one is the best and lets the AE work: http://www.bhphotovideo.com/c/product/646936-REG/Novoflex_MFT_PENT_Pentax_K_to_Micro.html Of course, it costs what a lens costs. On Tue, Mar 15, 2011 at 8:15 PM, J.C. O'Connell wrote: > seems like it would have to be off by more than 0.36mm for the > results your getting, something doesn't add up. > > -- > J.C. O'Connell (mailto:hifis...@gate.net) > Join the CD PLAYER & DISC Discussions : > http://tech.groups.yahoo.com/group/cdplayers/ > http://launch.groups.yahoo.com/group/cdsound/ > > > -Original Message- > From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of > Dario Bonazza > Sent: Tuesday, March 15, 2011 8:05 PM > To: Pentax-Discuss Mail List > Subject: Re: Pentax glass on m4/3: weird behavior > > > Let's do some math: > K bayonet register = 45.46mm > m4/3 register = 19.25mm > Then K-m4/3 adaptor must be 45.46 - 19.25 = 26.21mm > A caliper reads 25.85mm for my adaptor. > Hence it looks like being 0.35mm short. Is that enough for such a weird > behaviour? > > Dario > > - Original Message - > From: "Dario Bonazza" > To: "Pentax-Discuss Mail List" > Sent: Wednesday, March 16, 2011 12:41 AM > Subject: Re: Pentax glass on m4/3: weird behavior > > >> No name on it, found in ebay from Hong Kong. I bought it some time >> ago, >> but I can no longer find trace of that auction. However, it could be this >> one: >> > http://cgi.ebay.com/Pentax-PK-K-lens-Micro-4-3-Adapter-EP-1-GF1-G1-GH1-/2506 > 30349531?pt=Lens_Accessories&hash=item3a5abba2db >> >> Dario >> >> - Original Message - >> From: "Steven Desjardins" >> To: "Pentax-Discuss Mail List" >> Sent: Tuesday, March 15, 2011 11:53 PM >> Subject: Re: Pentax glass on m4/3: weird behavior >> >> >>> I'd like to hear this myself. What brand of adaptor? >>> >>> On Tue, Mar 15, 2011 at 6:02 PM, Dario Bonazza >>> wrote: >>>> Hello gang, >>>> >>>> I've just tried a few Pentax lenses on my Panny GF-1 (via K-micro4/3 >>>> adapter), just to find a weird behaviour. >>>> >>>> With close subjects (inches to meters), the actual distance of my >>>> subject >>>> (properly focused by looking at magnified LCD) can be similar to that >>>> one >>>> indicated on the distance scale of the lens. However, when trying to >>>> properly focus at infinity I have to set a much closer distance on the >>>> lens >>>> ring, with larger and larger offsets as focal legths shorten. >>>> >>>> Examples: >>>> 100mm lens focused at infinity -> focusing ring is set at 15-20m; >>>> 50mm lens focused at infinity -> focusing ring is set at 7-10m; 28mm >>>> lens focused at infinity -> focusing ring is set at 3m! >>>> >>>> With a Samyang 8mm fisheye, there's no way to focus (lens helicoid >>>> has >>>> no >>>> run enough to find focus). It happens that by setting the focus at its >>>> minimum focus distance, the lens is almost (but not yet) focused at >>>> infinity. By approaching the subject, things become worse. >>>> >>>> Have you ever seen anything like that? How would you explain that? >>>> Wrong adapter? Too short to set proper register distance for >>>> K-bayonet lenses? >>>> >>>> Cheers, >>>> >>>> Dario >> >> >> -- >> PDML Pentax-Discuss Mail List >> PDML@pdml.net >> http://pdml.net/mailman/listinfo/pdml_pdml.net >> to UNSUBSCRIBE from the PDML, please visit the link directly above and >> follow the directions. >> >> >> - >> Nessun virus nel messaggio. >> Controllato da AVG - www.avg.com >> Versione: 10.0.1204 / Database dei virus: 1498/3507 - Data di >> rilascio: >> 14/03/2011 >> > > > -- > PDML Pentax-Discuss Mail List > PDML@pdml.net > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and > follow the directions. > > > -- > PDML Pentax-Discuss Mail List > PDML@pdml.net > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow > the directions. > -- Steve Desjardins -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Pentax glass on m4/3: weird behavior
Your adapter is setting the mount register too deep. I had the same thing happen with a Pentax M42 adapter. I bought a different one, which allows focus slightly beyond infinity. Cost me $6 for the replacement. Most lens mount adapters for FourThirds and Micro-FourThirds intentionally run about half a millimeter short in order to ensure infinity focus with all lenses of that mount. This throws off the infinity focus point by a couple of degrees but is much less difficult to work with than adapters that are slightly too long, preventing proper infinity focus. On Tue, Mar 15, 2011 at 3:02 PM, Dario Bonazza wrote: > Hello gang, > > I've just tried a few Pentax lenses on my Panny GF-1 (via K-micro4/3 > adapter), just to find a weird behaviour. > > With close subjects (inches to meters), the actual distance of my subject > (properly focused by looking at magnified LCD) can be similar to that one > indicated on the distance scale of the lens. However, when trying to > properly focus at infinity I have to set a much closer distance on the lens > ring, with larger and larger offsets as focal legths shorten. > > Examples: > 100mm lens focused at infinity -> focusing ring is set at 15-20m; > 50mm lens focused at infinity -> focusing ring is set at 7-10m; > 28mm lens focused at infinity -> focusing ring is set at 3m! > > With a Samyang 8mm fisheye, there's no way to focus (lens helicoid has no > run enough to find focus). It happens that by setting the focus at its > minimum focus distance, the lens is almost (but not yet) focused at > infinity. By approaching the subject, things become worse. > > Have you ever seen anything like that? How would you explain that? Wrong > adapter? Too short to set proper register distance for K-bayonet lenses? > > Cheers, > > Dario > > -- > PDML Pentax-Discuss Mail List > PDML@pdml.net > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and > follow the directions. > -- Godfrey godfreydigiorgi.posterous.com -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Pentax glass on m4/3: weird behavior
On Tue, Mar 15, 2011 at 8:56 PM, Godfrey DiGiorgi wrote: > I bought a different one, which allows focus slightly beyond infinity. The Buzz Lightyear Signature Edition, of course. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Pentax glass on m4/3: weird behavior
The hugely expensive Novoflex adapters are only really necessary with Pentax lenses that do not have an aperture ring. They allow manual adjustment of the aperture by providing a secondary ring which moves the iris actuator mechanism, similar to but more flexible than what I used to do with the DA21 and DA70 when adapted to the L1 (I just stuck a little museum putty between the iris actuator and the adapter to set the lens opening I wanted to use). It has nothing to do with AE ... No lens adapter made that I've seen does the auto-iris thing. Auto Exposure is supported with any adapter in aperture priority mode: you set the lens opening you want and the camera sets the shutter speed to match it. Camera's don't need aperture position information to meter correctly that way. On Tue, Mar 15, 2011 at 5:20 PM, Steven Desjardins wrote: > The Novoflex one is the best and lets the AE work: > > http://www.bhphotovideo.com/c/product/646936-REG/Novoflex_MFT_PENT_Pentax_K_to_Micro.html > > Of course, it costs what a lens costs. > > On Tue, Mar 15, 2011 at 8:15 PM, J.C. O'Connell wrote: >> seems like it would have to be off by more than 0.36mm for the >> results your getting, something doesn't add up. >> >> -- >> J.C. O'Connell (mailto:hifis...@gate.net) >> Join the CD PLAYER & DISC Discussions : >> http://tech.groups.yahoo.com/group/cdplayers/ >> http://launch.groups.yahoo.com/group/cdsound/ >> >> >> -Original Message- >> From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of >> Dario Bonazza >> Sent: Tuesday, March 15, 2011 8:05 PM >> To: Pentax-Discuss Mail List >> Subject: Re: Pentax glass on m4/3: weird behavior >> >> >> Let's do some math: >> K bayonet register = 45.46mm >> m4/3 register = 19.25mm >> Then K-m4/3 adaptor must be 45.46 - 19.25 = 26.21mm >> A caliper reads 25.85mm for my adaptor. >> Hence it looks like being 0.35mm short. Is that enough for such a weird >> behaviour? >> >> Dario >> >> - Original Message - >> From: "Dario Bonazza" >> To: "Pentax-Discuss Mail List" >> Sent: Wednesday, March 16, 2011 12:41 AM >> Subject: Re: Pentax glass on m4/3: weird behavior >> >> >>> No name on it, found in ebay from Hong Kong. I bought it some time >>> ago, >>> but I can no longer find trace of that auction. However, it could be this >>> one: >>> >> http://cgi.ebay.com/Pentax-PK-K-lens-Micro-4-3-Adapter-EP-1-GF1-G1-GH1-/2506 >> 30349531?pt=Lens_Accessories&hash=item3a5abba2db >>> >>> Dario >>> >>> - Original Message - >>> From: "Steven Desjardins" >>> To: "Pentax-Discuss Mail List" >>> Sent: Tuesday, March 15, 2011 11:53 PM >>> Subject: Re: Pentax glass on m4/3: weird behavior >>> >>> >>>> I'd like to hear this myself. What brand of adaptor? >>>> >>>> On Tue, Mar 15, 2011 at 6:02 PM, Dario Bonazza >>>> wrote: >>>>> Hello gang, >>>>> >>>>> I've just tried a few Pentax lenses on my Panny GF-1 (via K-micro4/3 >>>>> adapter), just to find a weird behaviour. >>>>> >>>>> With close subjects (inches to meters), the actual distance of my >>>>> subject >>>>> (properly focused by looking at magnified LCD) can be similar to that >>>>> one >>>>> indicated on the distance scale of the lens. However, when trying to >>>>> properly focus at infinity I have to set a much closer distance on the >>>>> lens >>>>> ring, with larger and larger offsets as focal legths shorten. >>>>> >>>>> Examples: >>>>> 100mm lens focused at infinity -> focusing ring is set at 15-20m; >>>>> 50mm lens focused at infinity -> focusing ring is set at 7-10m; 28mm >>>>> lens focused at infinity -> focusing ring is set at 3m! >>>>> >>>>> With a Samyang 8mm fisheye, there's no way to focus (lens helicoid >>>>> has >>>>> no >>>>> run enough to find focus). It happens that by setting the focus at its >>>>> minimum focus distance, the lens is almost (but not yet) focused at >>>>> infinity. By approaching the subject, things become worse. >>>>> >>>>> Have you ever seen anything like that? How would you explain that? >>>>> Wrong adapter? Too short to set proper register distanc
Re: Pentax glass on m4/3: weird behavior
I stand corrected. I appreciate having a reason not to buy it. -Original Message- From: Godfrey DiGiorgi Sender: pdml-boun...@pdml.net Date: Tue, 15 Mar 2011 18:00:57 To: Pentax-Discuss Mail List Reply-To: Pentax-Discuss Mail List Subject: Re: Pentax glass on m4/3: weird behavior The hugely expensive Novoflex adapters are only really necessary with Pentax lenses that do not have an aperture ring. They allow manual adjustment of the aperture by providing a secondary ring which moves the iris actuator mechanism, similar to but more flexible than what I used to do with the DA21 and DA70 when adapted to the L1 (I just stuck a little museum putty between the iris actuator and the adapter to set the lens opening I wanted to use). It has nothing to do with AE ... No lens adapter made that I've seen does the auto-iris thing. Auto Exposure is supported with any adapter in aperture priority mode: you set the lens opening you want and the camera sets the shutter speed to match it. Camera's don't need aperture position information to meter correctly that way. On Tue, Mar 15, 2011 at 5:20 PM, Steven Desjardins wrote: > The Novoflex one is the best and lets the AE work: > > http://www.bhphotovideo.com/c/product/646936-REG/Novoflex_MFT_PENT_Pentax_K_to_Micro.html > > Of course, it costs what a lens costs. > > On Tue, Mar 15, 2011 at 8:15 PM, J.C. O'Connell wrote: >> seems like it would have to be off by more than 0.36mm for the >> results your getting, something doesn't add up. >> >> -- >> J.C. O'Connell (mailto:hifis...@gate.net) >> Join the CD PLAYER & DISC Discussions : >> http://tech.groups.yahoo.com/group/cdplayers/ >> http://launch.groups.yahoo.com/group/cdsound/ >> >> >> -Original Message- >> From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of >> Dario Bonazza >> Sent: Tuesday, March 15, 2011 8:05 PM >> To: Pentax-Discuss Mail List >> Subject: Re: Pentax glass on m4/3: weird behavior >> >> >> Let's do some math: >> K bayonet register = 45.46mm >> m4/3 register = 19.25mm >> Then K-m4/3 adaptor must be 45.46 - 19.25 = 26.21mm >> A caliper reads 25.85mm for my adaptor. >> Hence it looks like being 0.35mm short. Is that enough for such a weird >> behaviour? >> >> Dario >> >> - Original Message - >> From: "Dario Bonazza" >> To: "Pentax-Discuss Mail List" >> Sent: Wednesday, March 16, 2011 12:41 AM >> Subject: Re: Pentax glass on m4/3: weird behavior >> >> >>> No name on it, found in ebay from Hong Kong. I bought it some time >>> ago, >>> but I can no longer find trace of that auction. However, it could be this >>> one: >>> >> http://cgi.ebay.com/Pentax-PK-K-lens-Micro-4-3-Adapter-EP-1-GF1-G1-GH1-/2506 >> 30349531?pt=Lens_Accessories&hash=item3a5abba2db >>> >>> Dario >>> >>> - Original Message - >>> From: "Steven Desjardins" >>> To: "Pentax-Discuss Mail List" >>> Sent: Tuesday, March 15, 2011 11:53 PM >>> Subject: Re: Pentax glass on m4/3: weird behavior >>> >>> >>>> I'd like to hear this myself. What brand of adaptor? >>>> >>>> On Tue, Mar 15, 2011 at 6:02 PM, Dario Bonazza >>>> wrote: >>>>> Hello gang, >>>>> >>>>> I've just tried a few Pentax lenses on my Panny GF-1 (via K-micro4/3 >>>>> adapter), just to find a weird behaviour. >>>>> >>>>> With close subjects (inches to meters), the actual distance of my >>>>> subject >>>>> (properly focused by looking at magnified LCD) can be similar to that >>>>> one >>>>> indicated on the distance scale of the lens. However, when trying to >>>>> properly focus at infinity I have to set a much closer distance on the >>>>> lens >>>>> ring, with larger and larger offsets as focal legths shorten. >>>>> >>>>> Examples: >>>>> 100mm lens focused at infinity -> focusing ring is set at 15-20m; >>>>> 50mm lens focused at infinity -> focusing ring is set at 7-10m; 28mm >>>>> lens focused at infinity -> focusing ring is set at 3m! >>>>> >>>>> With a Samyang 8mm fisheye, there's no way to focus (lens helicoid >>>>> has >>>>> no >>>>> run enough to find focus). It happens that by setting the focus at its >>>>> minimum focus distance, the lens is almo
Re: Pentax glass on m4/3: weird behavior
Be ashamed, Matt. Privately pleased, but publically ashamed. -Original Message- From: Matthew Hunt Sender: pdml-boun...@pdml.net Date: Tue, 15 Mar 2011 20:59:11 To: Pentax-Discuss Mail List Reply-To: Pentax-Discuss Mail List Subject: Re: Pentax glass on m4/3: weird behavior On Tue, Mar 15, 2011 at 8:56 PM, Godfrey DiGiorgi wrote: > I bought a different one, which allows focus slightly beyond infinity. The Buzz Lightyear Signature Edition, of course. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Pentax glass on m4/3: weird behavior
You have two reasons, it's unnecessary if you use lenses with aperture rings and it's hugely expensive. On 3/15/2011 9:04 PM, drd1...@gmail.com wrote: I stand corrected. I appreciate having a reason not to buy it. -Original Message- From: Godfrey DiGiorgi Sender: pdml-boun...@pdml.net Date: Tue, 15 Mar 2011 18:00:57 To: Pentax-Discuss Mail List Reply-To: Pentax-Discuss Mail List Subject: Re: Pentax glass on m4/3: weird behavior The hugely expensive Novoflex adapters are only really necessary with Pentax lenses that do not have an aperture ring. They allow manual adjustment of the aperture by providing a secondary ring which moves the iris actuator mechanism, similar to but more flexible than what I used to do with the DA21 and DA70 when adapted to the L1 (I just stuck a little museum putty between the iris actuator and the adapter to set the lens opening I wanted to use). It has nothing to do with AE ... No lens adapter made that I've seen does the auto-iris thing. Auto Exposure is supported with any adapter in aperture priority mode: you set the lens opening you want and the camera sets the shutter speed to match it. Camera's don't need aperture position information to meter correctly that way. On Tue, Mar 15, 2011 at 5:20 PM, Steven Desjardins wrote: The Novoflex one is the best and lets the AE work: http://www.bhphotovideo.com/c/product/646936-REG/Novoflex_MFT_PENT_Pentax_K_to_Micro.html Of course, it costs what a lens costs. On Tue, Mar 15, 2011 at 8:15 PM, J.C. O'Connell wrote: seems like it would have to be off by more than 0.36mm for the results your getting, something doesn't add up. -- J.C. O'Connell (mailto:hifis...@gate.net) Join the CD PLAYER& DISC Discussions : http://tech.groups.yahoo.com/group/cdplayers/ http://launch.groups.yahoo.com/group/cdsound/ -Original Message- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Dario Bonazza Sent: Tuesday, March 15, 2011 8:05 PM To: Pentax-Discuss Mail List Subject: Re: Pentax glass on m4/3: weird behavior Let's do some math: K bayonet register = 45.46mm m4/3 register = 19.25mm Then K-m4/3 adaptor must be 45.46 - 19.25 = 26.21mm A caliper reads 25.85mm for my adaptor. Hence it looks like being 0.35mm short. Is that enough for such a weird behaviour? Dario - Original Message - From: "Dario Bonazza" To: "Pentax-Discuss Mail List" Sent: Wednesday, March 16, 2011 12:41 AM Subject: Re: Pentax glass on m4/3: weird behavior No name on it, found in ebay from Hong Kong. I bought it some time ago, but I can no longer find trace of that auction. However, it could be this one: http://cgi.ebay.com/Pentax-PK-K-lens-Micro-4-3-Adapter-EP-1-GF1-G1-GH1-/2506 30349531?pt=Lens_Accessories&hash=item3a5abba2db Dario - Original Message - From: "Steven Desjardins" To: "Pentax-Discuss Mail List" Sent: Tuesday, March 15, 2011 11:53 PM Subject: Re: Pentax glass on m4/3: weird behavior I'd like to hear this myself. What brand of adaptor? On Tue, Mar 15, 2011 at 6:02 PM, Dario Bonazza wrote: Hello gang, I've just tried a few Pentax lenses on my Panny GF-1 (via K-micro4/3 adapter), just to find a weird behaviour. With close subjects (inches to meters), the actual distance of my subject (properly focused by looking at magnified LCD) can be similar to that one indicated on the distance scale of the lens. However, when trying to properly focus at infinity I have to set a much closer distance on the lens ring, with larger and larger offsets as focal legths shorten. Examples: 100mm lens focused at infinity -> focusing ring is set at 15-20m; 50mm lens focused at infinity -> focusing ring is set at 7-10m; 28mm lens focused at infinity -> focusing ring is set at 3m! With a Samyang 8mm fisheye, there's no way to focus (lens helicoid has no run enough to find focus). It happens that by setting the focus at its minimum focus distance, the lens is almost (but not yet) focused at infinity. By approaching the subject, things become worse. Have you ever seen anything like that? How would you explain that? Wrong adapter? Too short to set proper register distance for K-bayonet lenses? Cheers, Dario -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. - Nessun virus nel messaggio. Controllato da AVG - www.avg.com Versione: 10.0.1204 / Database dei virus: 1498/3507 - Data di rilascio: 14/03/2011 -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly abov
Re: Pentax glass on m4/3: weird behavior
On Tue, Mar 15, 2011 at 9:06 PM, wrote: > Be ashamed, Matt. Privately pleased, but publically ashamed. Well, now you've done it. My blog has a new subhead. The previous one lasted all of 3 hours. http://scotchtape.ductwhisky.com/p/taglines.html -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Pentax glass on m4/3: weird behavior
On Mar 15, 2011, at 17:02, Dario Bonazza wrote: > > With a Samyang 8mm fisheye, there's no way to focus (lens helicoid has no run > enough to find focus). It happens that by setting the focus at its minimum > focus distance, the lens is almost (but not yet) focused at infinity. By > approaching the subject, things become worse. > Will purchase from you for $50 to ease your pain... -Charles -- Charles Robinson - charl...@visi.com Minneapolis, MN http://charles.robinsontwins.org http://www.facebook.com/charles.robinson -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Pentax glass on m4/3: weird behavior
On Tue, Mar 15, 2011 at 6:02 PM, Dario Bonazza wrote: > Examples: > 100mm lens focused at infinity -> focusing ring is set at 15-20m; > 50mm lens focused at infinity -> focusing ring is set at 7-10m; > 28mm lens focused at infinity -> focusing ring is set at 3m! I used the "Table Output" feature of the following web page for 100mm focal length and "Extension Length" checked: http://www.openphotographicsociety.org/index.php?option=com_content&view=article&id=646&Itemid=108 An extension of 0.306mm corresponds to a focus setting of 32.9 m. That's somewhat more than 15-20m, but it seems like your measured register offset of 0.35mm could be a significant contributor to the problem you encounter. Similarly, for a 50mm focal length, 0.383mm extension corresponds to 6.63m focus setting. Quite consistent with your findings. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Pentax glass on m4/3: weird behavior
Charles Robinson wrote: On Mar 15, 2011, at 17:02, Dario Bonazza wrote: With a Samyang 8mm fisheye, there's no way to focus (lens helicoid has no run enough to find focus). It happens that by setting the focus at its minimum focus distance, the lens is almost (but not yet) focused at infinity. By approaching the subject, things become worse. Will purchase from you for $50 to ease your pain... Har! I use it on my K-5 without much register problems... Dario -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Pentax glass on m4/3: weird behavior
Matthew Hunt wrote: On Tue, Mar 15, 2011 at 6:02 PM, Dario Bonazza wrote: Examples: 100mm lens focused at infinity -> focusing ring is set at 15-20m; 50mm lens focused at infinity -> focusing ring is set at 7-10m; 28mm lens focused at infinity -> focusing ring is set at 3m! I used the "Table Output" feature of the following web page for 100mm focal length and "Extension Length" checked: http://www.openphotographicsociety.org/index.php?option=com_content&view=article&id=646&Itemid=108 An extension of 0.306mm corresponds to a focus setting of 32.9 m. That's somewhat more than 15-20m, but it seems like your measured register offset of 0.35mm could be a significant contributor to the problem you encounter. Similarly, for a 50mm focal length, 0.383mm extension corresponds to 6.63m focus setting. Quite consistent with your findings. Many thanks! I believe that explains the problem. Dario -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.