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12-21-2011, 04:07 AM   #331
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QuoteOriginally posted by Digitalis Quote
As long as the original pentax K mount lens is kept at the required 45.46mm away from the sensor then there won't be a problem. The one big problem I can see is the issue of Ricoh/Pentax producing a FF EVIL camera would be with producing an entirely new line of lenses to make use of the shorter back-focus. i'm not suggesting that pentax lens designers are sloppy, I'm just saying they would have to produce a lot of lenses to keep users of the system happy. And then there is of course the issue of auto focus though there is a clever trick that pentax could possibly employ to provide AF even for manual focus lenses, but i'm not saying anything.. I should patent it first. *conspiratorial rubbing of hands *
If you mean focusing by moving the sensor, it has been done before for film (see Contax AX: www.youtube.com/watch?v=MjgV34PzKTA).
It should of course be simpler for a digital sensor.

12-21-2011, 04:11 AM   #332
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Cameras will eventually be no more than a 'film' coating on a pair of glasses...
12-21-2011, 04:46 AM   #333
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QuoteOriginally posted by Douglas_of_Sweden Quote
If you mean focusing by moving the sensor, it has been done before for film Contax AX. It should of course be simpler for a digital sensor.
That was sort of where I got the idea from. As I had the pleasure of owning a Contax AX, Aria, RTSII and III - I really liked those cameras I consider the Aria to be my favourite camera from the late 90's. For those who don't know the Contax AX used ceramics to control the travel of the focusing mechanism ceramics were used ensure the longevity and precision of the focusing mechanism, which was itself powered by an ultrasonic motor. Though the contax AX had a limitation: film plane could only move back and forth by 10mm. A digital sensor is inherently flatter than film is, so film flatness issues are no-longer a problem. And having a sensor on a moving platform also would be a real boon to macro photographers. Hypotherically speaking If we had around 20 or 30mm of travel for the sensor even an ordinary 50mm lens it would be quite possible to get around 1:2~3.5 magnification and with dedicated macro lenses it would be possible to get even higher magnifications. With a camera like that you could eschew pentaprisms and go completely EVIL because the focus could be based on contrast detection from the sensor itself.

Last edited by Digitalis; 12-21-2011 at 04:57 AM.
12-21-2011, 05:08 AM   #334
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QuoteOriginally posted by eddie1960 Quote
Add DFA 100 2.8 macro to that list. it was an updated fa 100 2.8 (updated twice in fact with the WR variant)
I am afraid it was not.

Pentax FA 100mm f/2.8 Macro:



Pentax D-FA 100mm f/2.8 Macro, including WR version:



Diagrams from Bojidar Dimitrov website Pentax Short Telephoto Prime Lenses

12-21-2011, 05:26 AM   #335
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Though not identical, that is certainly close enough to be called an "update". Certainly the DFA100 macro is based on the FA100 macro with some tweaking. Both cover FF.
12-21-2011, 05:42 AM   #336
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QuoteOriginally posted by Digitalis Quote
That was sort of where I got the idea from. As I had the pleasure of owning a Contax AX, Aria, RTSII and III - I really liked those cameras I consider the Aria to be my favourite camera from the late 90's. For those who don't know the Contax AX used ceramics to control the travel of the focusing mechanism ceramics were used ensure the longevity and precision of the focusing mechanism, which was itself powered by an ultrasonic motor. Though the contax AX had a limitation: film plane could only move back and forth by 10mm. A digital sensor is inherently flatter than film is, so film flatness issues are no-longer a problem. And having a sensor on a moving platform also would be a real boon to macro photographers. Hypotherically speaking If we had around 20 or 30mm of travel for the sensor even an ordinary 50mm lens it would be quite possible to get around 1:2~3.5 magnification and with dedicated macro lenses it would be possible to get even higher magnifications. With a camera like that you could eschew pentaprisms and go completely EVIL because the focus could be based on contrast detection from the sensor itself.
I see a few disadvantages with this type of design.

I wanting to keep sensor stabilization it will be a pretty big and heavy part that has to moved inside the camera.

By adding 20-30mm to the thickness of the camera you probably end up with a camera bigger and heavier than a DSLR.

One of the biggest advantage of EVIL is that by removing most complex mechanical parts manufacturing cost is lower, and quality can be kept higher. This will be lost if adding an even more complex mechanical design than a DSLR.

There might be a small market for a camera like this with FF sensor and optimized for manual focus lenses, but it probably end up with a Leica M9 price tag.
12-21-2011, 06:17 AM - 1 Like   #337
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QuoteOriginally posted by Fogel70 Quote
One of the biggest advantage of EVIL is that by removing most complex mechanical parts manufacturing cost is lower, and quality can be kept higher. .
Therre are several problems with this statement: a) The mirror mechanism is not very complex; b) It is cheap, and c) the mirror mechanism has a lower fault rate than the cametras electronics....
12-21-2011, 06:26 AM - 1 Like   #338
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QuoteOriginally posted by bossa Quote
Who needs Digital Photography when you can still buy film?
You had me until here.



12-21-2011, 06:58 AM   #339
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QuoteOriginally posted by Pål Jensen Quote
Therre are several problems with this statement: a) The mirror mechanism is not very complex; b) It is cheap, and c) the mirror mechanism has a lower fault rate than the cametras electronics....
It is complex as it is difficult to calibrate AF system perfectly. And BF/FF issues becomes a quality problem as it is to expensive to calibrate perfectly or set up 100% quality control.

The part itself does not have to be expensive for adding high cost on the final product.
12-21-2011, 07:11 AM   #340
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QuoteOriginally posted by Fogel70 Quote
It is complex as it is difficult to calibrate AF system perfectly. And BF/FF issues becomes a quality problem as it is to expensive to calibrate perfectly or set up 100% quality control.
Indeed, a DSLR needs to be calibrated on three variables with regards to the mirror box:

The distance between the bayonet mount and the...
- sensor
- AF module
- ground glass screen

Any difference between those three variables and the camera will show focusing errors.

A MILC camera does not have such a problem because there's only one variable: the distance between the mount and the sensor. So a mirror box MUST be more expensive because there's much more QC involved.
12-21-2011, 09:54 AM   #341
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QuoteOriginally posted by Asahiflex Quote
Indeed, a DSLR needs to be calibrated on three variables with regards to the mirror box:

The distance between the bayonet mount and the...
- sensor
- AF module
- ground glass screen

Any difference between those three variables and the camera will show focusing errors.

A MILC camera does not have such a problem because there's only one variable: the distance between the mount and the sensor. So a mirror box MUST be more expensive because there's much more QC involved.
And if were talking about CDAF then even the distance does not matter - only the alignment
12-21-2011, 10:00 AM   #342
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It does matter - if not calibrated properly you could lose the focus to infinity.
12-21-2011, 10:33 AM   #343
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You're now comparion 2 focus systems together....

You know sony use phase AF with their fixed mirror cameras while they can use Contrast AF just as easy.

Phase AF stil have its use because it know how to focus, contrast AF is a much dumber system.


ever tried to do track focus with contrast AF....
12-21-2011, 11:53 AM   #344
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QuoteOriginally posted by bossa Quote
Yeah, why use an iPod when an old Walkman cassette player is still kicking around in the garage? Who needs LBT or Hubble when Mount Palomar is still with us? Who needs Hi-res digital television when we have a perfectly healthy Lo-Res CRT TV? Who needs Digital Photography when you can still buy film? ..on and on and on I could go here...zzzz

We're 'always' happy with what we have until something revolutionary shows us something way more interesting.

My records on my hi-end stero has better sound quality than my CD's on the same hig-end system. An ipod just don't have the sound quality for me. An ipod is convienent and that it about all. Now my HD flatcreen is a different story. It has a lot better quality than my old tube TV plus the new technology makes it more convienent.

So new technology just to be new is not an end in itself. Just replacing a optical viewfinder with an EVF just to decrease the register distance a few millimeters just doesn't do it for me. Yes, an EVF will make the camera alittle less expensive to make, but is about all at this time.

Dave
12-21-2011, 12:04 PM   #345
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QuoteOriginally posted by junyo Quote
I agree with your basic point, but reach a different conclusion.

I tend to think that Pentax's lack of traction has had more to do with philosophy and lack of aggression rather than specific technology. Pentax has encouraged and attracted a certain level of stick-in-the-mud-ists, re-living the glory days of the LX rather than aggressively making the case for their current products.

K mount is essentially golden handcuffs. Even if they wanted to, they can't afford to leave it. Ricoh bought Pentax. If they wanted to re-invent the wheel they could've focused on their own existing quirky camera operation. Pentax gives them a larger base of customers with goodwill. They obviously want to preserve that. So I think the eye of the needle involves leveraging K mount in the short term to get room for more stuff down the road. Incrementally better SLR's might keep some of the faithful at home, but it's not going to build the brand (to your point). If they're not designing a K mount GXR module right this second, they're crazy. Also, I'd be looking very closely at removing the prism hump from the K-r chassis, paring it down as much as possible, sticking a small EVF in the top left corner and releasing that as an MILC... My ad copy would say "The only MILC with a full lens lineup, and full lens compatibility to an SLR system, day one." And personally, I'd buy that, versus a NEX7/X100/Fuji MILC that I intend to buy next, just because it would be a value proposition.

So far the only MILC that interest me is the NEX7 but the lack of lenses will keep me from buying it. A K-r shassis with weather-sealing and a small EVF in the top left corner would be great. I would buy one in an instant just because of all my K-mount lenses could be use on it plus with the large dslr size battery the camera should get good battery life. Maybe for the extra few millimeters of depth by keeping the K-mount register distance a control wheel could be added around the lens mount like the old OM series cameras.

Anyhow, I am sure Pentax/Ricoh will do what they want. The Pentax Q proves that. Still the K-r is due for replacement and there was a rumor APS-C cmaera that was going to reach the market late this year but was put on hold after Ricoh purchased Pentax. It will take a year or two for any Ricoh inspire Pentax products to reach the market so I would expect something that is already in final design to reach the market early this coming year. What it will be is the big question. I am holding off purchasing any camera gear until I figure out what direction Pentax is heading. If it is the diriction I want to go then I will order a Sigma 500/4.5 unless Pentax is going to come out with a high-end super-telephoto.

Dave
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