Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
02-13-2015, 01:59 PM - 1 Like   #31
Senior Member




Join Date: Oct 2013
Photos: Gallery | Albums
Posts: 265
QuoteOriginally posted by rawr Quote
Forgive my ignorance, but when I mount a Pentax (or any other) manual lens on my NEX-F3 via a simple dumb PK-NEX adapter, as I adjust the aperture, the camera just continuously meters the scene according to the light the lens lets in. I then simply manually focus and shoot.

Would a stop-down coupler enable Pentax lenses without the A setting to behave the same way on a Pentax DSLR (ie no need to use the green button to meter the scene with K or M series lenses, just adjust aperture on the lens, focus and then shoot)?
Yes -- and moreover, unlike the adapter scenario you described, the aperture would remain wide open until you take the picture. So you would still get the brightest possible viewfinder, for easier focusing.
The coupler tells the camera what setting the aperture ring is at, so the camera can use that plus the amount of light coming in (at wide open) to deduce the correct exposure.

So you get both full-time metering as with adapted lenses (like M42) and wide-open focusing and composing as with K/M lenses.


Last edited by Scintilla; 02-13-2015 at 02:00 PM. Reason: unclear grammar
02-13-2015, 02:02 PM   #32
Pentaxian
Uluru's Avatar

Join Date: May 2010
Location: Back to my Walkabout Creek
Photos: Gallery | Albums
Posts: 2,400
The aim of engineering is to reduce complexity, not add to it. Pentax DSLR like K3 is already fairly more complicated than Nikon's DSLR that do have a coupler. Adding more mechanical parts adds more possible engineering issues, which they want to reduce.
But speaking of that, maybe they have something else, a solution even easier and is a part/side-effect of another technology incorporated in the FF, but they will not talk about it now. However, even if they do not deliver it, green button works.
02-13-2015, 02:21 PM   #33
Veteran Member
blende8's Avatar

Join Date: Feb 2007
Location: Bremen, Germany
Photos: Albums
Posts: 1,484
Original Poster
QuoteOriginally posted by Uluru Quote
green button works.
It only works quite inaccurate, as has been discussed on this forum numerous times.

---------- Post added 02-13-15 at 10:23 PM ----------

QuoteOriginally posted by boriscleto Quote
Nikon never put electrical contacts on the F-mount until the AF era.
Ah, ok, thanks!
02-13-2015, 03:01 PM   #34
Pentaxian




Join Date: Jun 2009
Location: GMT +10
Photos: Albums
Posts: 10,600
QuoteOriginally posted by Scintilla Quote
Yes -- and moreover, unlike the adapter scenario you described, the aperture would remain wide open until you take the picture.
Aha. Thanks for clearing that up. The NEX way seems more elegant.

It's a pity that even when shooting a Pentax DSLR using Liveview mode (not using the optical viewfinder), that stop down metering and the green-button are still required. In Liveview mode with a camera like the K-3, when you have access to focus peaking and a big bright LCD, requiring green button use and that the lens be kept wide open until you trip the shutter seems a bit redundant.

02-13-2015, 03:08 PM   #35
Veteran Member




Join Date: Apr 2011
Location: California
Photos: Gallery
Posts: 1,354
QuoteOriginally posted by monochrome Quote
  1. We can't do the aperture coupler and small
  2. But legacy-lens Pentax enthusiasts are important (especially in Japan)
  3. How about Green Button stop-down metering? - it is a 'solution'
Frankly, I believe a generous solution. They could have just punted.
Generous? I think you could look at an empty glass and call it half-full.

Camera bodies from the 1970's, which were smaller than today's cameras, somehow had space to fit the coupling lever. Aside from a warp in the space-time continuum, it really doesn't make sense that there is now not enough space to fit the lever.

Maybe the SR system has something to do with it? Who knows. Either way, it's an insult to our intelligence to not explain it. My ZX-5n is also smaller than any DSLR, yet it has space for the lever.

---------- Post added 02-13-15 at 02:10 PM ----------

When I use my ME Super and ZX-5n, I often think about the fact that current dslrs are less functional, in this one particular regard. That seems like a giant step backward.
02-13-2015, 03:13 PM   #36
Veteran Member




Join Date: Mar 2012
Location: Perrineville, NJ
Posts: 1,364
What Nikon does with their lenses has nothing to do with the Pentax situation. Pentax hasn't supported the aperture coupler for years -- there is no absolutely no incentive for them to suddenly introduce that capability today, as if it would attract new Pentax users? In fact, with a new FF body and new FF lenses on the market, they have even more reasons not to.

QuoteOriginally posted by ogl Quote
It seems to me that they buried this idea many years ago. There is space in any camera. They found simple excuse.
Yes, I agree. Like I said, if they really wanted to better support old lenses, they could easily sequence the green button and shutter release electronically, triggered by a single user operation, and that wouldn't require any additional hardware or space. The camera could sequentially "push" both buttons faster and more reliably than any human could. But because we asked specifically about the aperture coupler, (rather than a broader question about better support for old lenses,) they were able to come up with this as an excuse.
02-13-2015, 04:10 PM   #37
Loyal Site Supporter
THoog's Avatar

Join Date: Aug 2012
Location: North Carolina
Photos: Gallery | Albums
Posts: 3,401
QuoteOriginally posted by Tanzer Quote
What Nikon does with their lenses has nothing to do with the Pentax situation. Pentax hasn't supported the aperture coupler for years -- there is no absolutely no incentive for them to suddenly introduce that capability today, as if it would attract new Pentax users? In fact, with a new FF body and new FF lenses on the market, they have even more reasons not to.
This. What financial incentive is there for Pentax to spend time and money developing (almost from scratch) the mechanical, electronic, and software mechanisms needed to support 30+ year old lenses? How many MORE people would buy an "uncrippled" high-end Pentax body than a "crippled" one? Apart from a marketing bullet point and good will from old glass collectors, it needs to be profitable for them to do so. Rather than asking again and again and not liking the answer, we need to provide them with a solid monetary justification for doing it.
02-13-2015, 04:18 PM   #38
Site Supporter
geomez's Avatar

Join Date: Mar 2013
Location: Preskit Arizona
Photos: Gallery
Posts: 1,561
QuoteOriginally posted by Tanzer Quote

Yes, I agree. Like I said, if they really wanted to better support old lenses, they could easily sequence the green button and shutter release electronically, triggered by a single user operation, and that wouldn't require any additional hardware or space. The camera could sequentially "push" both buttons faster and more reliably than any human could. But because we asked specifically about the aperture coupler, (rather than a broader question about better support for old lenses,) they were able to come up with this as an excuse.


I petition that next time we have a Q&A with Pentax, we propose a firmware solution to the problem instead of asking them the same thing time and again and expecting a different answer.

02-13-2015, 04:22 PM   #39
Site Supporter
jcdoss's Avatar

Join Date: Nov 2012
Location: Kansas City, MO
Photos: Gallery | Albums
Posts: 1,810
Hypothetically speaking, one could choose to purchase a Sony a7II instead of a Pentax, if all one wants is an image stabilized platform on which to use legacy manual focus lenses. Lost customers are hard to win back.
02-13-2015, 04:39 PM   #40
Loyal Site Supporter
THoog's Avatar

Join Date: Aug 2012
Location: North Carolina
Photos: Gallery | Albums
Posts: 3,401
QuoteOriginally posted by jcdoss Quote
Hypothetically speaking, one could choose to purchase a Sony a7II instead of a Pentax, if all one wants is an image stabilized platform on which to use legacy manual focus lenses. Lost customers are hard to win back.
If that's all one wants, it's pretty hard to argue for staying with Pentax anyhow - the a7II will probably cost considerably less and be able to use other brands' legacy glass as well. I don't think the aperture coupler would make much of a difference, compared to the EVF/OVF or video arguments.
02-13-2015, 04:40 PM   #41
mee
Site Supporter




Join Date: May 2010
Posts: 5,258
They want you to buy new lenses... the general support for older lenses is just a carrot dangling you towards buying the camera body.
02-13-2015, 05:00 PM   #42
Senior Member
OJGoreng's Avatar

Join Date: Jun 2010
Location: Amsterdam
Photos: Gallery
Posts: 182
QuoteOriginally posted by rullrich Quote
What`s so wrong with the green button? I use it quite often on my K-5, and most of the time the camera is mounted on a tripod when I do. So it's a rather slow procedure anyway, where the green button is no burden. Or am I getting something wrong?
You have basically answered your own question; it's a slow procedure, which makes it useless in a situation where action is involved. If you compare that to the instant operation on, say, the lowly ME film body, it's an extreme hassle. I think that's part of the frustration... any 80s entry-level body had the mechanism, yet the current, hyperdengineered expensive models cannot perform this function, despite having the little lever required for closing the aperture on an old lens.
02-13-2015, 05:03 PM   #43
Administrator
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 40,993
QuoteOriginally posted by Asahiflex Quote
What surprises me is that the answer was: "I think it is important". Because there's never been a DSLR with an aperture coupler since the *ist D.
The 645D/Z both have the aperture coupler. But based on that interview answer, I don't think the FF will. Too bad, but not a deal breaker IMO.

Adam
PentaxForums.com Webmaster (Site Usage Guide | Site Help | My Photography)



PentaxForums.com's high server and development costs are user-supported. You can help cover those costs by donating. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

02-13-2015, 05:27 PM   #44
Veteran Member




Join Date: Apr 2011
Location: California
Photos: Gallery
Posts: 1,354
QuoteOriginally posted by THoog Quote
If that's all one wants, it's pretty hard to argue for staying with Pentax anyhow - the a7II will probably cost considerably less and be able to use other brands' legacy glass as well. I don't think the aperture coupler would make much of a difference, compared to the EVF/OVF or video arguments.
This is a pretty good argument for including the functionality, in my opinion. Does Ricoh want me to buy their camera or Sony's? We already know they are losing business to Sony. I can't imagine they like it.

Like most photographers, I want to keep purchasing new lenses and expanding my capabilities, but I don't want to have to stop using the equipment I've had for years. Being known as the company that best caters to its clients' wishes can't be bad for business. Making excuses about why technology that was perfected a few decades ago is no longer feasible due to lack of space in larger cameras can be bad for business.

How would people with DA Limited lenses feel if the FF had no crop capabilities? Probably not too happy.
02-13-2015, 05:29 PM   #45
Senior Member
deus ursus's Avatar

Join Date: Nov 2012
Location: Stårheim, Norway
Posts: 270
Wouldn't OTF metering like on the LX be a work-around? With K and M lenses you could set the aperture with the aperture ring, and the camera would meter the light hitting the sensor and close the shutter when enough light has hit the sensor.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
aperture, apertures, button, camera, coupler, glass, lens, lenses, lever, names, nb, niche, pentax, pentax news, pentax rumors, population, post, ricoh, space, stop, user, zx-5n
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
What will the FF be like? Na Horuk Pentax Full Frame 52 02-06-2015 09:42 AM
Odd behaviour from Super A - aperture doesn't stop down Jonathan Mac Pentax Film SLR Discussion 15 10-21-2014 11:07 PM
Stop with the FF sensors will be the same price nonsense. normhead Pentax Full Frame 196 01-11-2014 12:21 AM
stop down coupler and t mount converter not meshing blackest Troubleshooting and Beginner Help 0 07-08-2013 07:22 PM
if there will be a FF pentax - will pentax enforce a reduced image from DA40 ? deejjjaaaa Pentax SLR Lens Discussion 7 08-20-2008 05:19 AM



All times are GMT -7. The time now is 10:22 PM. | See also: NikonForums.com, part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top