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07-14-2012, 01:09 PM   #3106
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QuoteOriginally posted by markku55 Quote
Why are nearly all m4/3 lenses so so dam dark and expencive?
? I have a 14/2.5, 20/1.7 and 45/1.8, neither of which I would call dark or expensive.

07-14-2012, 01:43 PM   #3107
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QuoteOriginally posted by pingflood Quote
? I have a 14/2.5, 20/1.7 and 45/1.8, neither of which I would call dark or expensive.
What I mean here is that the shorter register distance do not make the wideangles cheaper than in FF range with longer register distance.
14mm F2,5 vs 28mm F2,5 (actually it should be only F5) and price is normally close to 300€, but as we know there is lenses with lower prices which are taken from some kit, even half the price, but those are not always available.
20mm F1,7 vs 40-50mm F1,7, price normally about 350€, you can get 50mm F1,8 for FF les than 200€.
45mm F1,8 vs 85mm F1,8, not anymore an normal or wideangle, and seems to be cheap to do, because it is like a normal for FF, but with narrower angle of view.
Look specially at wideangle zooms.
07-14-2012, 02:47 PM   #3108
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QuoteOriginally posted by Mistral75 Quote
Not more difficult than to fit a 24x36 mirror in a 45mm register distance.

APS-C is roughly 16x24mm and 45÷30 = 24÷16 = 36÷24 = 1.5 .

Remember that Pentax mount's register distance is 45.46mm, Canon EF's (the shortest of all 24x36 DSLR mounts) is 44mm and Alpa's (the shortest of all 24x36 SLR mounts) is 37.8mm.
First off, your calculation assumes everything is scaleable.

Second, the 4/3 registration distance is 38.6 mm. If it's such an advantage to have short registration distance, why did a recent mount with a even-smaller-than-APS-C mirror have such a large registration distance?
07-14-2012, 04:42 PM   #3109
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QuoteOriginally posted by ElJamoquio Quote
First off, your calculation assumes everything is scaleable.
(...)
What would not be scalable, apart from shutter thickness (a few tenths of millimetre)?

QuoteOriginally posted by ElJamoquio Quote
(...)
Second, the 4/3 registration distance is 38.6 mm. If it's such an advantage to have short registration distance, why did a recent mount with a even-smaller-than-APS-C mirror have such a large registration distance?
Because all 4/3 lenses are to be telecentric (that's part of the 4/3 rules), in which case the registration distance plays a much lesser role.

Besides, one cannot say that 4/3 has been a huge success...

07-14-2012, 11:13 PM   #3110
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QuoteOriginally posted by Asahiflex Quote
A Pentax FF could and should be something the others are not. I.e. smaller, rugged, completely weather sealed, photographer-centric controls, with IQ on absolute position #1. I do not need superb tracking AF and the like, but I would like the best viewfinder of any FF camera out there.
Sony's Alpha 900 probably had the best viewfinder of any FF camera. It's ironic that it's replacement will probably have the worse viewfinder on any FF camera...
07-15-2012, 12:28 AM   #3111
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QuoteOriginally posted by Mistral75 Quote
What would not be scalable, apart from shutter thickness (a few tenths of millimetre)?

Because all 4/3 lenses are to be telecentric (that's part of the 4/3 rules), in which case the registration distance plays a much lesser role.

Besides, one cannot say that 4/3 has been a huge success...
What makes you think even the mirror can be proportionally scalable? So far, nobody told me exactly what determines the mirror's size (and yes, I'd really like to know); so it's really about suppositions and guessing.

Are you saying the registration distance of a 4/3 DSLR could be smaller? By how much, and how do you know?

4/3 failing is irrelevant, by the way. How about the Alpa mount, being dead and buried doesn't count in their case?
07-15-2012, 07:24 AM   #3112
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QuoteOriginally posted by Kunzite Quote
What makes you think even the mirror can be proportionally scalable? So far, nobody told me exactly what determines the mirror's size (and yes, I'd really like to know); so it's really about suppositions and guessing.
(...)
I have some difficulties to imagine any use for the mirror's diagonal to be bigger than the lenses' image circle...

QuoteOriginally posted by Kunzite Quote
(...)
Are you saying the registration distance of a 4/3 DSLR could be smaller? By how much, and how do you know?
(...)
Yes I am. Remember Pentax 110? A SLR with film size of 13x17mm, i.e. the size of the 4/3 sensor. Registration distance? 27mm i.e. 11.6mm less than the 4/3 mount's.

Last edited by Mistral75; 07-15-2012 at 07:31 AM.
07-15-2012, 07:47 AM   #3113
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Isn't it so that the light shoul come to the sensor as close to 90 degree angle as possible?
If so, the shorter register distance will be some kind of a problem, as it is according to my understanding in the case of Leica M9, Leica have to modify the wideangle lenses to fit better to the short register distance to digital sensor, or have I understood wrong?

07-15-2012, 08:23 AM   #3114
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QuoteOriginally posted by markku55 Quote
Isn't it so that the light shoul come to the sensor as close to 90 degree angle as possible?
If so, the shorter register distance will be some kind of a problem, as it is according to my understanding in the case of Leica M9, Leica have to modify the wideangle lenses to fit better to the short register distance to digital sensor, or have I understood wrong?
Th short register distance is not a problem per see (as long as it remains reasonable). The problem is that short register distance allowed (during film era) for so-called "symmetric" or "semi-symmetric" lens designs. Such lenses are quite compact but, indeed, lead to peripheral rays which are pretty inclined, something that sensors do not like at all. So Leica had to opt for retrofocus designs for their new wide angle lenses, to the expense of compactness and weight.

So you can have a digital camera with a short register distance (shorter than the sensor's diagonal) as long as its wide angle lenses are retrofocus (and therefore quite big). Think of NEX and Carl Zeiss 24mm f/1.8 for instance.

SLRs' wide angle lenses, even those from the film era, are almost all retrofocus: symmetric lenses would protrude into the mirror box and oblige to lock the mirror in the up position (there were a few such lenses in the past).
07-15-2012, 09:33 AM   #3115
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Size matters

I can't help but bring up the obvious concerning camera / lens size / registration distance / new mount, etc. I also recognize that many people here have a lot of expertise on the technical aspects of camera and lens design. I am not dismissing their efforts to prove their points. This is all just purely my opinion.

In America anyway, size matters. People actually want big. "Big" is bragging rights to "Better" in America. People in America still want bigger cars, bigger houses, bigger offices, bigger plate portions of food, etc. Any efforts to save the environment, or better the average American's health, will not result smaller thinking. We will find ways to preserve our lifestyles regardless. Shrinking a dSLR by 10%, or so, will make zero difference to most Americans. Given what we have seen from the American influence on other countries it seems like thinking big is pervasive. I would be interested to hear other takes on this from people in other countries.

Last edited by lammie200; 07-15-2012 at 09:51 AM.
07-15-2012, 10:17 AM   #3116
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Here in England I think that size is important. Smaller is almost always better in my opinion. -unless there is other overriding things that make the slightly larger things more desirable. Which is why I went for a k-r with a da40 over a k-7 as it was. Much cheaper too.

In terms of FF-IMHO it's a matter of when rather than if.
If Pentax under Ricoh is only going to be dslr and mirror less, and they are employing more staff and investing more money- they will do FF at some point.

Hopefully a Simmilar sort of thing to te rounded d600. Otherwise they will lose out. That with the limiteds would be great. Need some decent ultra-wide angles though.

With the shift from amateur-> enthusiast, Pentax would be well placed with its weather sealing etc and a full lineup.
Just my opinion though.
07-15-2012, 10:30 AM   #3117
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At least one american likes smaller things.
07-15-2012, 11:14 AM   #3118
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QuoteOriginally posted by ElJamoquio Quote
At least one american likes smaller things.

PM me I've got a small "thing".
07-15-2012, 11:18 AM   #3119
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QuoteOriginally posted by Mistral75 Quote
I have some difficulties to imagine any use for the mirror's diagonal to be bigger than the lenses' image circle...

Yes I am. Remember Pentax 110? A SLR with film size of 13x17mm, i.e. the size of the 4/3 sensor. Registration distance? 27mm i.e. 11.6mm less than the 4/3 mount's.
I never said anything about the mirror being larger than that. But what's the exact size, and why?
The quick visual test I was mentioning few times will show how little space there is left, how little there is to gain; why won't you do it?

Pentax 110? Can it have a 100% viewfinder with f/1.2 lenses? You're trying hard to ignore any possible drawback of having a smaller mirror.
07-15-2012, 12:04 PM   #3120
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QuoteOriginally posted by Kunzite Quote
(...)
Pentax 110? Can it have a 100% viewfinder with f/1.2 lenses? You're trying hard to ignore any possible drawback of having a smaller mirror.
I am only trying (not so hard ) to answer your questions (those you have asked, not those you are about to raise) and point out some specific details. This "100% viewfinder with f/1.2 lenses" is a new point you are putting on the table.

Lens maximum aperture has nothing to do with mirror size. With mount diameter and registration distance, yes, with mirror size no. All things being equal, the shorter the registration distance, the easier the design of f/1.2 or brighter lenses. For instance: I am not even sure the 4/3 mount allows for f/1.2 lenses whilst there are f/0.95 lenses with µ4/3 mount.

On the other hand, viewfinder coverage has indeed to do with mirror size: obviously, a 100% viewfinder supposes that the mirror is at least as big as the sensor (slightly bigger, in fact).

Again, I was just answering your former question "Are you saying the registration distance of a 4/3 DSLR could be smaller? By how much, and how do you know?" in my former post: yes / by at least 11.6mm / see Pentax 110. But do not hesitate adding new considerations if having the last word is so important to you. I won't mind .
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