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09-23-2009, 02:32 PM   #106
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QuoteOriginally posted by falconeye Quote
True.

I just wanted to highlight that an ideal telecentric (or retrofocus) wideangle doesn't have vignetting because it has even illumination of a magnitude an ideal natural lens of the same size (not optical aperture) would have in the corners (the 2.6EV difference for 12mm APS-C).

This is new insight for me. I didn't know it beforehand. The nice thing is that it gives us a formula for maximum aperture with retrofocus wide angle lenses. A formula I didn't know it exists. (The formula would take FoV and permissable corner vignetting.)

You are right that the cos^4 applies to resolution as well. But again, the center resolution of a simpler natural lens may be much higher due to its more straight-forward design and the stellar performamce of some M mount wide angle lenses seem to confirm this. So again, the same logic may apply.


In short words:

It may be that a retrofocus lens is having degraded center performance rather than a natural lens is having degraded corner performance.

I don't know for sure. But we should take this possibility into account. I believe, it makes a difference in your path of arguments.

Anyway, this consideration was new to me and I wanted to share.
Well I have certainly learned a lot. A good debate is always illuminating.

Looking at Photozone I dont see a lot of retrofocus lenses with poor centre performance. Quite the opposite in fact. I dont think sticking a diverging lens in front of natural lens necessarily creates an inverse falloff.

09-23-2009, 05:27 PM   #107
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QuoteOriginally posted by *isteve Quote
Looking at Photozone I dont see a lot of retrofocus lenses with poor centre performance. Quite the opposite in fact.
Well, non retrofocus prime lenses normally outresolve the sensor in the center. Zeiss normal primes are said to outresolve the K20D center by 3x at f/4 (300 lp/mm). So, we don't know. And of course, center performance will always be better in the center, retrofocus designs included. The question is by how much.

The measured DA12 at f/4 center resolution is certainly a good one. But still FA31 at f/4 is better. And DA14 at f/4 center resolution really isn't that great. Looks like an 14mm/2.8 lens is over the edge for a retrofocus design already.

I believe that for the M mount, you get the strongest performers (resolution wise) for short focal lengths (the rays simply have less distance to diverge...). In the 24mm range or so. I am not sure though.

Again, I am still making up my mind. Interesting stuff.
09-24-2009, 02:26 AM   #108
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QuoteOriginally posted by falconeye Quote
Well, non retrofocus prime lenses normally outresolve the sensor in the center. Zeiss normal primes are said to outresolve the K20D center by 3x at f/4 (300 lp/mm). So, we don't know. And of course, center performance will always be better in the center, retrofocus designs included. The question is by how much.

The measured DA12 at f/4 center resolution is certainly a good one. But still FA31 at f/4 is better. And DA14 at f/4 center resolution really isn't that great. Looks like an 14mm/2.8 lens is over the edge for a retrofocus design already.

I believe that for the M mount, you get the strongest performers (resolution wise) for short focal lengths (the rays simply have less distance to diverge...). In the 24mm range or so. I am not sure though.

Again, I am still making up my mind. Interesting stuff.

I reckon there are a whole bunch of engineers at Pentax and Sony (and probably Canon) having exactly the same debate right now.

I suspect Sony will look to optimise the sensor for M use. Possibly keep the silicon but change the microlens and AA filter design. I suspect they will also be using in-camera processing and new lens designs.

Leica use offset microlenses but no AA filter. I am wondering, can you actually have an offset AA filter? It would strike me as highly problematic. Perhaps Leica dont have one simply because they cannot.

However, if your sensor has a particularly small pixel pitch (sensor resolution is greater than lens resolution) the need for an AA filter is reduced. Perhaps one answer is not to have an offset AA filter (which would magnify light falloff) but a variable one which is stronger in the centre and weaker at the edges.

This would remove moire but also even out the resolution between centre and edge of frame. How to make a variable filter? Hmm.
09-24-2009, 09:38 AM   #109
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falconeye and *isteve, I feel like I'm taking a course in optics and camera design by reading your posts. You guys probably forgot more than I know about the subject! Thanks for sharing your knowledge.

It is interesting to note how the E-P1 and GF1 have ended up roughly the same size, suggesting that they are at the limit of current technology at their particular pricepoint. I think one place where it can be shrunk further is with regards to power. Look at the following:



The battery occupies nearly that whole side of the E-P1 and a good percentage of its overall size.

Likewise the Panasonic GF1:



If you visualize the rest of the camera, all that's left is the optical path behind the lens and the LCD display and computer circuitry on the back. There's not much else.

So with miniaturization, we may be able to shave the circuit boards a little, and the thickness of the display (not the size though - people like big screens and for many it makes photography a social activity). And based on what you two are discussing, it sounds like there are limits to what can be done with the optical path to make it more compact.

But imagine replacing that Lithium Ion battery with a button-sized fuel cell - that's how the camera is going to shrink!

09-24-2009, 10:12 AM   #110
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QuoteOriginally posted by johnmflores Quote
It is interesting to note how the E-P1 and GF1 have ended up roughly the same size, suggesting that they are at the limit of current technology at their particular pricepoint. I think one place where it can be shrunk further is with regards to power.

The battery occupies nearly that whole side of the E-P1 and a good percentage of its overall size.

Likewise the Panasonic GF1:

If you visualize the rest of the camera, all that's left is the optical path behind the lens and the LCD display and computer circuitry on the back. There's not much else.

So with miniaturization, we may be able to shave the circuit boards a little, and the thickness of the display (not the size though - people like big screens and for many it makes photography a social activity). And based on what you two are discussing, it sounds like there are limits to what can be done with the optical path to make it more compact.

But imagine replacing that Lithium Ion battery with a button-sized fuel cell - that's how the camera is going to shrink!
Personally I think the issue is the form factor not the size. This insistance on slavish observance to a past shape makes cameras harder to pocket because you have basically a flat box with a lens sticking out.

The form factor of some early digicams was far more imaginative. Take the Coolpix 990 for instance. There was room for a decent sized zoom lens but the body folded flat which made it easier to carry.
Nikon Coolpix 990 Review: 1. Intro: Digital Photography Review

Read the review by the way and pause for thought. We have come a long way with the technology but how much have our photos improved?

Im sure some imagination could be applied, though I have seen none in the camera industry in 5 years. Everything looks the same.
09-24-2009, 05:37 PM   #111
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QuoteOriginally posted by johnmflores Quote
The battery occupies nearly that whole side of the E-P1 and a good percentage of its overall size.
[...]
If you visualize the rest of the camera, all that's left is the optical path behind the lens and the LCD display and computer circuitry on the back. There's not much else.
I think the photo of the bottom also tells that there is space left: it shares depth with the SD card mechanism and has a height which is less than the body height (about 10mm left). Put a smaller DLux-4 battery and it should be ok too.

However, I heard that E_P1's battery life could be better and maybe, the embedded processing pipeline just is yet too power hungry for a smaller battery.


What is not visible though, and what Steve and I are discussing, is by how much larger the mount is compared to the sensor chip inside.

The mFT mount has an approx. diameter of 42mm and the sensor chip of 22mm. If you look from the front of the mount into the empty chamber you'll see a small sensor chip which almost looks lost in the large chamber behind the mount.

A smaller registration distance and much smaller mount diameter would have been required to fully instrumentalize the power of the mFT idea. IMHO, they blew it.

Steve argues that a smaller mount would have compromised the optical quality because it would have made telecentric designs with large apertures difficult. I argue that the Leica M mount (scaled by 0.5x due to the smaller sensor) would have been good enough.

mFT mount:
reg distance: ~20mm
mount diameter: ~42mm

0.5x M mount:
reg distance: ~14mm
mount diameter: ~22mm

IMHO, the bulk is an inevitable consequence from the mFT specification.

I consider it somewhat of a joke when Olympus specified the FT mount to be almost the same size as their OM mount (85% flange and 115% diameter), for a sensor half the size ... Unfortunately, they still suffer from the bulk syndrome.

QuoteOriginally posted by *isteve Quote
Personally I think the issue is the form factor not the size.
+1
09-24-2009, 07:45 PM   #112
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QuoteOriginally posted by Pål Jensen Quote
Or for that matter, the coming 645D as most 645 lenses are discontinued....
Yea, but there are so many Pentax 645 lenses floating around in the used market RELATIVE to the number of people that are going to buy the 645D. AND, many med. format users are content with just three primes.
09-25-2009, 04:23 AM   #113
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QuoteOriginally posted by falconeye Quote
I think the photo of the bottom also tells that there is space left: it shares depth with the SD card mechanism and has a height which is less than the body height (about 10mm left). Put a smaller DLux-4 battery and it should be ok too.

However, I heard that E_P1's battery life could be better and maybe, the embedded processing pipeline just is yet too power hungry for a smaller battery.


What is not visible though, and what Steve and I are discussing, is by how much larger the mount is compared to the sensor chip inside.

The mFT mount has an approx. diameter of 42mm and the sensor chip of 22mm. If you look from the front of the mount into the empty chamber you'll see a small sensor chip which almost looks lost in the large chamber behind the mount.

A smaller registration distance and much smaller mount diameter would have been required to fully instrumentalize the power of the mFT idea. IMHO, they blew it.

Steve argues that a smaller mount would have compromised the optical quality because it would have made telecentric designs with large apertures difficult. I argue that the Leica M mount (scaled by 0.5x due to the smaller sensor) would have been good enough.

mFT mount:
reg distance: ~20mm
mount diameter: ~42mm

0.5x M mount:
reg distance: ~14mm
mount diameter: ~22mm

IMHO, the bulk is an inevitable consequence from the mFT specification.

I consider it somewhat of a joke when Olympus specified the FT mount to be almost the same size as their OM mount (85% flange and 115% diameter), for a sensor half the size ... Unfortunately, they still suffer from the bulk syndrome.
I think I agree that the mount diameter is larger than it needs to be. This I assume is so that can make converters to existing 4/3 lenses (and OM lenses) which is a marketing not an engineering decision.

I say again, I doubt the mass appeal of an interchangeable lens format to the target market. Micro cameras with non-interchangeable lenses could be made much smaller without compromising optical quality, or image quality.

I wonder if its an evolutionary dead end.

I think the real future for micro cameras will have APS (or slightly smaller) sensors with a built in 5 to 10X zoom.

09-25-2009, 05:17 AM   #114
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QuoteOriginally posted by *isteve Quote
I wonder if its an evolutionary dead end.
You may be right here.
One the other hand and you said it already, it is astonishing how little change there is in the evolution of camera concepts.

It will be intersting to observe how the niche between camera phones and system cameras evolves -- or vanishes.


If we talk about the very long term ....

... then I see two end points of the evolution:


1. the future phones which photograph and videograph thru a small wireless zoom lens you could attach to your phone or your glasses (24/7 recording).

2. digital lenses (pretty much the system camera lenses we have today as mandated by the laws of physics) with digital endcaps: a sensor build into the lens endcap with specifications matching the lens (resolution, image circle).


So, I have no idea about the medium future. There seem to be a number of dead ends involved

But at least, you could consider a camera like the LX3 to be on the evolutionary path towards a true digital lens (Leica 5.1–12.8/2.0-2.8 with 9.8mm endcap). So, the difference between P&S and system cameras would vanish as both fuse into digital lenses of various sizes (the system part would morph into backup storage and field monitor facilities).

Last edited by falconeye; 09-25-2009 at 05:33 AM.
09-25-2009, 07:26 AM   #115
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QuoteOriginally posted by falconeye Quote
You may be right here.
One the other hand and you said it already, it is astonishing how little change there is in the evolution of camera concepts.
Yes, after a promising start (Coolpix 990, Sony 707 etc) its all become very predictable (read "safe").

QuoteQuote:
It will be intersting to observe how the niche between camera phones and system cameras evolves -- or vanishes.
Well, physics still has sway over phonecams, but they have already made a big dent in the low end digicam market. I think digicams will have to become much more functional (fully video capable with zoom, stereo input, etc) to remain viable.

I think micro 4/3 has arisen out of the real desire for "smaller but with decent IQ" and for Samsung and Panasonic with no access to the inter-licensing agreements that exist between Pentax, Canon, Nikon, Oly and Sony, the mirrorless system allows them complete freedom to design and build their own camera systems without license fees.

The danger is that small SLRs can get very very close to the requirements of "small, high IQ, proper camera" but with a much more extensive system and upgrade path. For people who really want in to a system and upgrade path, micro is a dead end. Its really just taking over from the bridge camera so I think a lot of them will end up with fixed lenses.

Low end plastic toy SLRs will go away and good riddance. The SLR entry point will get higher, but there will still not be any real competition (legacy will see to that).

So in 3 years I would estimate we will have the following camera types, with overlap between each level....

Phone cams
Digital compacts with full movie support
EVF 4/3 and APS cameras with fixed lenses
EVF 4/3 and APS cameras with interchangeable lenses
APSC SLRs
FF SLRs
MF digital SLRs.

QuoteQuote:

If we talk about the very long term ....

... then I see two end points of the evolution:


1. the future phones which photograph and videograph thru a small wireless zoom lens you could attach to your phone or your glasses (24/7 recording).

2. digital lenses (pretty much the system camera lenses we have today as mandated by the laws of physics) with digital endcaps: a sensor build into the lens endcap with specifications matching the lens (resolution, image circle).


So, I have no idea about the medium future. There seem to be a number of dead ends involved

But at least, you could consider a camera like the LX3 to be on the evolutionary path towards a true digital lens (Leica 5.1–12.8/2.0-2.8 with 9.8mm endcap). So, the difference between P&S and system cameras would vanish as both fuse into digital lenses of various sizes (the system part would morph into backup storage and field monitor facilities).
The long term future? Well, thats an interesting one. I believe there will be two technology breakthroughs in sensors and optics and evolution of processing power allowing far more performance and much higher IQ.

Sensor developments seem to be focusing on noise, DR and resolution. Hybrids of CMOS and CCD sensors will allow CMOS readout speed and low dark-current noise with CCD fill factors and low readout noise. (see this)

sCMOS - Scientific CMOS White Paper and Image Downloads

In the longer term they may even combine this technology with Foveon arrays to improve real resolution as well. This will require much faster processors but I think thats entirely possible.

Optics? Really compact lenses would contain objective elements which would be variable RI liquids held between glass plates and controlled by computer. They would effectively be able to correct for any aberation in real time and would not have to be round either - in fact they could be rectangular to match the sensor which would reduce their size and mass even more.

No corrective lenses will be required so the mass and size would be tiny. Wide angle lenses with F numbers less that 1 would be entirely possible.

And OLEDS could eventually allow full modularity of systems, much as you suggested. Your "personal" module is just your iPhone equivalent (though very thin and flexible). This will contain a screen, basic phone and internet device and a few GB of solid state storage (plus permanent uplink). The camera "module" will simply be a device that can be used as an attachment, or remotely via wireless. Live view plus controls will all be on the phone, the camera will be a lens/sensor/processor/storage device in various sizes depending on usage.

I think thats a way off yet, but someone will make something similar within a decade I am fairly confident - even if it does not replace SLRs in that timeframe it wil replace almost every other consumer format for stills and video.
09-25-2009, 04:03 PM   #116
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QuoteOriginally posted by *isteve Quote
Yes, after a promising start (Coolpix 990, Sony 707 etc) its all become very predictable (read "safe").
Hmm, when you mentioned the Coolpix 990, I remembered another "swiveling" camera, the Pentax Optio X (Pentax Optio X: Digital Photography Review) . Pentax also had some other interesting P&S cameras: The Optio S was amazingly stylish and compact for its time, the retro-look 750z also was a really cool camera. But then, a couple of years ago, suddenly only the W series stood out from the crowd.
09-26-2009, 04:01 AM   #117
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QuoteOriginally posted by *isteve Quote
So in 3 years I would estimate we will have the following camera types, with overlap between each level....

Phone cams
Digital compacts with full movie support
EVF 4/3 and APS cameras with fixed lenses
EVF 4/3 and APS cameras with interchangeable lenses
APSC SLRs
FF SLRs
MF digital SLRs.

Seems to be a safe bet as this describes the current situation pretty well. Only "EVF 4/3 cameras with fixed lenses" is missing (APS-C is here).

QuoteOriginally posted by *isteve Quote
The long term future? Well, thats an interesting one. I believe there will be two technology breakthroughs in sensors and optics and evolution of processing power allowing far more performance and much higher IQ.
Full agreement.

What I tried to highlight is that I foresee a landslide shift in distribution of value between the optics (glass staying valuable) and electronics (silicon becoming penny value). You are right about the progress in sensors but sooner or later, you cannot but count the photons as they arrive...

The progress with liquid lenses and alike would be crucial for my "phone camera" category, less so for my "digital lens" category.

Overall, I share your vision about the future.
09-26-2009, 06:11 AM   #118
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QuoteOriginally posted by falconeye Quote

Seems to be a safe bet as this describes the current situation pretty well. Only "EVF 4/3 cameras with fixed lenses" is missing (APS-C is here).


Full agreement.

What I tried to highlight is that I foresee a landslide shift in distribution of value between the optics (glass staying valuable) and electronics (silicon becoming penny value). You are right about the progress in sensors but sooner or later, you cannot but count the photons as they arrive...

The progress with liquid lenses and alike would be crucial for my "phone camera" category, less so for my "digital lens" category.

Overall, I share your vision about the future.
Exciting isnt it?

Theoretically the maximum resolution achieveable from an APS sensor would be about 2X the wavelength of red light.... On a 23mm X 15 mm sensor that would resolve about 175 MP. The real limit is lens diffraction.

Some way to go yet.
09-26-2009, 08:31 AM   #119
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QuoteOriginally posted by *isteve Quote
Yes, after a promising start (Coolpix 990, Sony 707 etc)
Yikes, those two camera designs were promising to you? I absolutely despised both concepts. I bought a Canon Powershot G2 instead of a Coolpix 995 simply because I hated that swivel nonsense. As far as the Sony 707 goes, I simply don't understand the point of camera design like that. I'd much rather have something like a Panasonic GH1 where if I don't mind a big lens I can put the 14-140mm on it, and for times wen I want something smaller mount a 20mm pancake on it. Like my Canon G2 the GH1 also has a rotating LCD, which is even more versatile than a vertical swiveling body, and much easier to use also.

Maybe I like retro too much (the Leica M9 makes me drool), but I think we have a pretty good grasp of what shape a camera should be now after a century development and the boat doesn't really need to be rocked anymore. If anything I wish DSLR makers would go back in time 30 years and make designs like the Pentax K1000 again. I'm extremely tired of standard DSLR design (K20D, D300, 50D, etc). I'd love to see grip-less SLR's come back. I never had an issue using a K1000 for hours in college just like I don't have any issues using my E-P1 now. To me a grip is just unnecessary bulk.

Last edited by Art Vandelay II; 09-26-2009 at 08:37 AM.
09-26-2009, 02:24 PM   #120
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QuoteOriginally posted by *isteve Quote
Theoretically the maximum resolution achieveable from an APS sensor would be about 2X the wavelength of red light....
Actually, it is 2X the wavelength of red light (in lp) for an f/1.64 diffraction-limited lens as they exist for microscopes but no other devices. In practice, the fact that reasonably large diffraction-limited lenses below f/4.0 aren't affordable sets a limit.

This sets the APS-C limit more at 100 MPixel. IMHO, APS-C will be more cost-effivient up to 40 MPixel and FF will be more cost-efficient up to 100 MPixel. Beyond, MF will be cheapest.
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