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05-31-2013, 02:59 PM   #1861
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I don't think I'm wrong, but maybe I didn't express myself clear enough?
Assuming a precise DOF computation is needed, you can do it directly for the format you're using. Assuming an approximation is good enough, you can use the experience with the format you're using (and that's not limited to the viewfinder image, which I agree is not that accurate).
In both cases, converting to and from a foreign format is an unnecessary complication.

05-31-2013, 03:13 PM   #1862
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Maybe I was concentrating more on your comment about looking through the viewfinder, which is easier than doing the DoF calculation, of course. It's one area where an EVF is better than an OVF, for all its other qualities or shortcomings.
05-31-2013, 03:46 PM   #1863
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QuoteOriginally posted by ElJamoquio Quote
Equivalency makes it very easy to compare systems with differing sensor sizes. Equivalency simplifies comparison. You don't have to worry about calculating any FOV or DOF's.

Calculate the equivalency - which is as simple as multiplying aperture and focal length by crop factor - and you'll know that you're comparing two cameras taking the same picture.
Explaining equivalency in 135 terms to someone who has only ever known digital's flux of standards, is like explaining metric to Americans.

Duck and run......
05-31-2013, 04:17 PM   #1864
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QuoteOriginally posted by falconeye Quote
I keep saying this for years, but I disagree on time scale.

For one thing, it doesn't make sense to assume lenses to bring their own sensor covering their respective image circle. And at the same time, to ignore the fact that each optical quality has its own sweet spot for sensor size, including full frame and beyond and below.

I would assume that such sweet spot is around the lens' entrance pupil diameter, or maybe half of it, as image circle diamater.

Actually, such a lens would scream for a "retina sensor" with very high resolution in the center (suitable for cropping and exploiting the lens' center resoving power) and lower resolution towards the outer limits of the lens image circle (which can become *very* large for long lenses, but with lower lens resolution). Much like what our eye does.

And for another thing, it assumes sensor cost to be marginalized. Which will happen but hasn't happened yet and won't happen over the next 10 years either. The GXR is too early.
Graphene sensors are supposedly 1000x more light sensitive than CMOS sensors and 5x cheaper to make using the same CMOS techniques. This sounds like a big step in making that concept a possibility.

05-31-2013, 04:37 PM   #1865
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QuoteOriginally posted by RonHendriks1966 Quote
I wonder how many people really don't care about this (like myself). I have a nice set off lenses and choose the one I think will bring me what I'm looking for. I look true my viewfinder or the screen on my K-01 to see if I have to zoom with my feet or not.
Ohh, now I pretty well know what I want to use and put it on without thinking of that. I know my equipment! When I was new however...
05-31-2013, 05:03 PM   #1866
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QuoteOriginally posted by Aristophanes Quote
Explaining equivalency in 135 terms to someone who has only ever known digital's flux of standards, is like explaining metric to Americans.

Duck and run......
Now, I agree. Except it is the other way round. Legacy is king in the US, read 135 terms.

But with a plethora of sensor sizes nobody is able to keep track with (mobile phones, premium mobile phone, compact, enthusiast compact, pureview, CX, FourThirds, APSC, 135, cropped medium format, true medium format, ...) photographers would really really benefit tremendeously if cameras were labelled in SOME equivalent way (I don't care if it is 135mm or 1" or whatever). Labelling in an equivalent way means relabelling focal length, F-stop and ISO.

Most of us use cameras of different formats and it is getting a bit annoying ...

There is currently only one factor preventing it: mounts which are shared between sensor sizes, like EOS or F-Mount.

Such a scaled labelling isn't unprecedented: lens apertures are labelled as focal length scaled by aperture diameter. An abstract concept but simplifying a photographers life enough that we don't even think about today.

I do not advocate equivalent labelling of cameras. Time will tell. Only that discussions about sensor sizes remain factually correct by comparing apples to apples.
05-31-2013, 05:31 PM   #1867
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QuoteOriginally posted by falconeye Quote
Now, I agree. Except it is the other way round. Legacy is king in the US, read 135 terms.

But with a plethora of sensor sizes nobody is able to keep track with (mobile phones, premium mobile phone, compact, enthusiast compact, pureview, CX, FourThirds, APSC, 135, cropped medium format, true medium format, ...) photographers would really really benefit tremendeously if cameras were labelled in SOME equivalent way (I don't care if it is 135mm or 1" or whatever). Labelling in an equivalent way means relabelling focal length, F-stop and ISO.

Most of us use cameras of different formats and it is getting a bit annoying ...

There is currently only one factor preventing it: mounts which are shared between sensor sizes, like EOS or F-Mount.

Such a scaled labelling isn't unprecedented: lens apertures are labelled as focal length scaled by aperture diameter. An abstract concept but simplifying a photographers life enough that we don't even think about today.

I do not advocate equivalent labelling of cameras. Time will tell. Only that discussions about sensor sizes remain factually correct by comparing apples to apples.
I suspect the relabelling is already happening to some extent but it is based not around camera terms but around devices and platforms. There are smartphones and smartphone journalism, or perhaps iPhone journalism, then there is FB, YouTube, Instagramming it and all the rest. In the case of the Pentax WG series, for example, the marketing stuff I've read is keen to call it everything but a camera. It's "Your most adventurous friend". And in all these cases, video is just as or sometimes more important than stills.

Tablets are still in their infancy. But being much bigger than mobile phones and with much bigger batteries, they probably have quite a lot of scope to pack more sophisticated cameras with bigger sensors and with that a whole new breed of labels and terms and things you can do will emerge too.

I've never heard anyone ask what the focal length of an iPhone camera is and I don't expect I ever will. And given what one reads about camera manufacturers cooking ISO values, perhaps that one is not a very reliable metric these days either.

For purists and those seriously interested, it's all still there. But I can't help feeling they are a declining breed and the old way of doing things is slowly slipping away. The emphasis now is on what the stuff does, not so much on how the stuff does it.
05-31-2013, 06:02 PM   #1868
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QuoteOriginally posted by mecrox Quote
I suspect the relabelling is already happening to some extent but it is based not around camera terms but around devices and platforms. There are smartphones and smartphone journalism, or perhaps iPhone journalism, then there is FB, YouTube, Instagramming it and all the rest. In the case of the Pentax WG series, for example, the marketing stuff I've read is keen to call it everything but a camera. It's "Your most adventurous friend". And in all these cases, video is just as or sometimes more important than stills.

Tablets are still in their infancy. But being much bigger than mobile phones and with much bigger batteries, they probably have quite a lot of scope to pack more sophisticated cameras with bigger sensors and with that a whole new breed of labels and terms and things you can do will emerge too.

I've never heard anyone ask what the focal length of an iPhone camera is and I don't expect I ever will. And given what one reads about camera manufacturers cooking ISO values, perhaps that one is not a very reliable metric these days either.

For purists and those seriously interested, it's all still there. But I can't help feeling they are a declining breed and the old way of doing things is slowly slipping away. The emphasis now is on what the stuff does, not so much on how the stuff does it.
Well said.

This guy makes me want FF:

A Sony RX1 Review | The Golden Sieve

05-31-2013, 06:20 PM   #1869
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QuoteOriginally posted by Aristophanes Quote
This guy makes me want FF:
Any camera review by a talented photographer and image processor - eg Ming Thein - makes me feel like buying the device he is reviewing. It's a trap.

Even if I bought the same gear as some of these reviewers, my results would be less impressive and most likely not be any testimony to the IQ of the camera.

Last edited by rawr; 05-31-2013 at 06:26 PM.
05-31-2013, 06:31 PM   #1870
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QuoteOriginally posted by bossa Quote
Graphene sensors are supposedly 1000x more light sensitive than CMOS sensors
Hmmm? I've never done the calculations myself but I was under the impression the efficiency of changing photons to electrons was 20-40% on current CMOS sensors... which if true make '1000x' (or anything more than 2.5-5x better) an impossibility.
05-31-2013, 07:02 PM   #1871
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QuoteOriginally posted by ElJamoquio Quote
Hmmm? I've never done the calculations myself but I was under the impression the efficiency of changing photons to electrons was 20-40% on current CMOS sensors... which if true make '1000x' (or anything more than 2.5-5x better) an impossibility.
2-4x increased efficiency is for practical application. The remaining 250-500x is for selling and marketing
05-31-2013, 07:52 PM   #1872
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QuoteOriginally posted by bossa Quote
Graphene sensors are supposedly 1000x more light sensitive than CMOS sensors and 5x cheaper to make using the same CMOS techniques. This sounds like a big step in making that concept a possibility.
Also bear in mind that Quantum dots have also been proposed as a candidate digital camera sensors.

The problem with graphene is that mechanically and thermodynamically it isn't really all that stable, especially when it is made to be thin and flat like a digital sensor - graphene tends to want to curl up like a scroll which is its lowest energy rest state. Personally I don't think any one particular material should be used for a sensor, I would prefer a composite that delivers as few drawbacks as possible - silicon could provide a structural support for the material as well as a thermal buffer - thin sheets of graphene have been known to develop small temperature variations that can cause it to crumple and warp.
05-31-2013, 08:33 PM   #1873
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QuoteOriginally posted by ElJamoquio Quote
I never knew that the 14 bit, or something else, actually made a difference. It isn't 2 stops, it's 0.7 EV, but that's still at least measureable.

[/url]
at ISO100, then - only ~ 0.5EV
05-31-2013, 10:23 PM   #1874
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QuoteOriginally posted by ElJamoquio Quote
Hmmm? I've never done the calculations myself but I was under the impression the efficiency of changing photons to electrons was 20-40% on current CMOS sensors... which if true make '1000x' (or anything more than 2.5-5x better) an impossibility.
From what I can gather the 1000x improvement in sensitivity refers to previous graphene-based designs. Current CMOS sensors already have a quantum efficiency of 60-90% (back-illumination) so the improvement potential is obviously dramatically less than what the article implies.
06-01-2013, 04:53 AM   #1875
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Pentaxians always amaze me.
So many confident experts on the physics of graphene, photonics, sensor design - you name it
It's like I'm auditing an online course offered by Stanford or something.
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