Photocracy
The Great Pretender
Reged: 18/11/2006
Posts: 493
Loc: Sunny South Coast
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The miniaturised nature of 4/3rds photography is not generally appreciated. Perhaps it would be illuminating to start a 4/3rds lens facts discussion. There are various issues which deserve more attention and here's a few to start. Add more.
4/3rds pictures are not 'cropped' as is so often implied disparagingly. The term cropping implies oversized lenses are used with much of the image being wasted in a larger than sensor image circle. In fact, the image circle of 4/3rds lenses is purposely designed to cover only the sensor and no more.
Enjoy affordable and publishable quality 21.4 x magnification. The standard 14mm-42mm provides a 35mm equivalent of a 28mm lens on a 4/3rds camera. Attaching the 70-300mm lens provides a 35mm (or 'full frame') equivalent of a 600mm lens. From the 14mm starting point, this provides a 21.4 x magnification factor in a size which fits in a very small bag and can easily be carried up hill and down dale.
As a miniaturised format, the same light admitting power or aperture (f number), meaning for the same lens speed, the image produced by the 4/3rds camera lens will have an appreciably greater depth of of field.
(let's get the 82% of jokes out of the way now so they need not divert any discussion).
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Rob
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Benchista
Wich Tyler
Reged: 11/08/2000
Posts: 37017
Loc: Everywhere and nowhere, baby
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Putting aside the rather odd concept of "publishable quality" (who defines exactly what that means? It's just as arbitary as any other measure...) for a moment, my biggest issue with the most commonly-used 4/3 lenses is precisely that they AREN'T very miniaturised. It's why I applaud the new pancake lens - for me, the whole point of 4/3 should be that it treads in the footsteps of the Pen F and OM systems, and provides respectable quality in a very compact form. I think the size and weight of the long lenses is a little bit of a red herring - many press togs will tell you how much easier it is to hold a long lens. Where Oly really need to make an effort (for me, at least) is in the 21-200mm equivalent range, the area where the OM system was so very effective. It's why I personally like the 4xx series more than the 5xx - I just wish Oly would put IS into the 4xx body and improve the handling a bit and I would buy one in a flash even if it cost more than the 5xx, as it would have a real benefit for me. Other than size, there's frankly no compelling reason I can see to buy into 4/3 when other systems offer more quality and ability to crop for a similar size and cost. Obviously YMMV.
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Nick
www.nbrphoto.com
Light and Shade II - the new blog
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daft_biker
Action Man!
Reged: 11/10/2006
Posts: 7186
Loc: Doon the glen
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RE the appreciably greater DoF; any chance of some pictures that show the effect in practice?
Should be easy to show the difference between large format and a digital compact but I don't expect the differences between APS-C and 4/3rds to be that great. I think it's more a theoretical advantage than a practical one that can be demonstrated.
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Andrew (BSRIPN) ... Pics.
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Photocracy
The Great Pretender
Reged: 18/11/2006
Posts: 493
Loc: Sunny South Coast
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I have deliberately used the concept of publishable quality (PQ) to try to bring some common sense back into the IQ debate. I don't think magazines (who after all do most of the reviews) would have any problem at all deciding if images produced by a camera passed their own quality test for publication. Furthermore, we are the consumers of publishable quality images and I think we all have a pretty good idea if something is fit (quality wise) to appear in magzines and books or not. It is a much more meaningful concept than camera X exeeding the image quality of camera Y at 100% on a monitor. It relates IQ to practical use, instead of the theoretical 'top trumps' which camera manufacturers (and magazines I hasten to add) are very adept at using to make today's model appear obsolete by the end of the week.
Of course, camera reviewers would still be able to rave about how much a camera might exeed PQ, but buyers would know immediately that any PQ camera was suitable for their purposes up to a given size of image. It is also a measuring concept which does not age. PQ in 1998 is the same as PQ in 2008, so we would be able to assess the capability of old or new digital cameras much more evenly. Present methodology tends to cast as second or third rate those cameras which do not win the IQ test, yet they may be perfectly good and capable of PQ while offering other features which a buyer might prefer.
"Capable of publishable quality" is a concept used by Ivor Matanle in his Classic SLRs book . Lenses are graded using a 4 star rating, with 4 stars designating PQ. This tells us if a 1960s lens is fit for serious use today.
I agree that some of the 4/3rds lenses aren't that small but I think Olympus is addressing this. The second generation of standard kit lenses saw quite a reduction in size and I think we will see the potential for miniaturisation pressed home as time passes. At only 5 years old, the ZD lens system is still in it's infancy. The advantage is indeed more apparent with longer lenses.
Yes, I very much agree about the desirability of IS in a 4xx body. It would be a very attractive camera. Let's hope it comes next time around.
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Rob
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Photocracy
The Great Pretender
Reged: 18/11/2006
Posts: 493
Loc: Sunny South Coast
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Quote:
RE the appreciably greater DoF; any chance of some pictures that show the effect in practice?
Should be easy to show the difference between large format and a digital compact but I don't expect the differences between APS-C and 4/3rds to be that great. I think it's more a theoretical advantage than a practical one that can be demonstrated.
Actually, I gleaned this information from "All About Using a Miniature" published by Focal Press, 1956!  I agree the difference between APS-c and 4/3rds is likely to be small as APS-c is itself a slightly miniaturised format.
Yes it would be good to explore this. Presumably you want a picture with a wide aperture, where DOF can easily be assessed? (e.g. down the side of some railings?) I'll try to do something to put up. Which lens; standard zoom?
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Rob
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zuiko
Olympian...
Reged: 19/06/2006
Posts: 428
Loc: Norfolk.
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Publishing quality could easily be defined as that which is accepted by top stock photography agencies. They do have high QC and pixel peep. Why isn't it done? At least punters would have a better idea of where there intended purchase is placed. The problem is of course there would be no podiums or percentages due to the one level of accepted excellence.
David
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" ENCEFFC!" "ENNSEAEFFSEA!"" ENNCEFFC!" "ENNCEEFC!"
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Fen
BAD WOLF
Reged: 12/03/2002
Posts: 20174
Loc: Currently Unknown!
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I don't think you can use PQ at all, especially if you're going to base it on what stock agencies want.
Yes, a camera might be able to produce images of a good enough quality.
BUT, can the photographer say the same? There's loads of talk on the Alamy related forums at the moment (mainly by one woman) about the QC procedures there and how her images keep failing. Although she won't admit it, in the photos that she's shown it's quite easy to see why she has failed QC so many times.
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Fen .......... My Galleries - My Blog - My Flickr
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zuiko
Olympian...
Reged: 19/06/2006
Posts: 428
Loc: Norfolk.
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This isn't about photographers but about capabilities of equipment. Does it meet the required standard. If the answer is yes then it is up to the individual to educate themselves to use it. A camera is a tool after all. QC failure at Alamy is another minefield but ultimately they are usually correct and it is the Photographer that is at fault
How is it going for you, any sales yet?
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" ENCEFFC!" "ENNSEAEFFSEA!"" ENNCEFFC!" "ENNCEEFC!"
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Photocracy
The Great Pretender
Reged: 18/11/2006
Posts: 493
Loc: Sunny South Coast
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Quote:
I don't think you can use PQ at all, especially if you're going to base it on what stock agencies want.
Yes, a camera might be able to produce images of a good enough quality.
BUT, can the photographer say the same? There's loads of talk on the Alamy related forums at the moment (mainly by one woman) about the QC procedures there and how her images keep failing. Although she won't admit it, in the photos that she's shown it's quite easy to see why she has failed QC so many times.
I think the key to this is Ivor Matanle's use of the word "capable", as in "capable of publishable quality". I can't see why camera reviewers would have any difficulty whatsoever in applying this quality threshold. If the failure comes from the photographer I think this would be easy enough to observe, as in the case you refer to.
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Rob
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Benchista
Wich Tyler
Reged: 11/08/2000
Posts: 37017
Loc: Everywhere and nowhere, baby
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Indeed: it's at best a grey area. And anyway, if the content is unique or interesting enough, the quality isn't a factor. Personally, I've always liked Roger Hicks' idea of "acceptable quality", but that definition varies from individual to individual, according to usage, and probably also varies with time; in short I simply don't think it's possible to define a quality threshold that's universally acceptable below which a camera is classed as no good and above which no improvement in quality is considered worthwhile, because that's just not how the world is - and anyway, far from levelling the playing field, it seems to me that it's simply a way of artificially minimising the disadvantages of 4/3 in camera tests, which at the end of the day is of no benefit to end users, is it? The choice of camera is always a compromise, and each individual needs to decide for themselves what weight to give to each aspect. Trying to hide one aspect to me seems pretty daft, TBH, and entirely unhelpful. Where do you go next - say that as all cameras are under 5 kg they're all of acceptable weight, so that's not an issue? Or that as all cameras can focus in under 10 seconds, AF speed isn't an issue? I know I've exagerated both of these examples, but my point is that on ALL such issues, people's requirements differ and it's really not the place of a review to impose standards of acceptability; they're for the individual to determine according to his/her own requirements.
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Nick
www.nbrphoto.com
Light and Shade II - the new blog
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LargeFormat
old hand
Reged: 24/10/2006
Posts: 1063
Loc: Buckinghamshire and Cumbria
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Quote:
Should be easy to show the difference between large format and a digital compact
Usually at something like f32 with large format so not much of a comparison anyway. The difference between APSc and 4/3 is comparable to a 33mm against a 25mm as the equivalent of a standard 50mm on full frame.
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Bone_Idle
Mr Maybe
Reged: 28/07/2006
Posts: 1324
Loc: Bradford
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I think the new kit lenses were a step in the right direction. Good quality and pretty small, especially the 40-150mm which is not much bigegr than the standard zoom. Is there another lens of that size that gives an 35mm focal length of 300mm?
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Thanks
Nick
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Photocracy
The Great Pretender
Reged: 18/11/2006
Posts: 493
Loc: Sunny South Coast
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Quote:
Indeed: it's at best a grey area. And anyway, if the content is unique or interesting enough, the quality isn't a factor. Personally, I've always liked Roger Hicks' idea of "acceptable quality", but that definition varies from individual to individual, according to usage, and probably also varies with time; in short I simply don't think it's possible to define a quality threshold that's universally acceptable below which a camera is classed as no good and above which no improvement in quality is considered worthwhile, because that's just not how the world is - and anyway, far from levelling the playing field, it seems to me that it's simply a way of artificially minimising the disadvantages of 4/3 in camera tests, which at the end of the day is of no benefit to end users, is it? The choice of camera is always a compromise, and each individual needs to decide for themselves what weight to give to each aspect. Trying to hide one aspect to me seems pretty daft, TBH, and entirely unhelpful. Where do you go next - say that as all cameras are under 5 kg they're all of acceptable weight, so that's not an issue? Or that as all cameras can focus in under 10 seconds, AF speed isn't an issue? I know I've exagerated both of these examples, but my point is that on ALL such issues, people's requirements differ and it's really not the place of a review to impose standards of acceptability; they're for the individual to determine according to his/her own requirements.
It would not work in the way that you sugggest, nor would it artificially minimise or hide the maximum image size (disadvantage if you insist) of any camera. As an appraisal threshold it would have to be linked to a size, such as the A series paper format. The range is A10, A9, A8, A7, A6, A5, A4, A3, A2, A1, A0, 2A0, 4A0 with A10 being about the size of a large stamp, and 4A0 being about 1.6 metres x 2.4 metres.
This would cater for everything from the lowest resolution camera phone, to Canon's 'medium format killer'. It would be an easy way of telling the buying public what a camera is capable of (e.g. capable of publishable quality up to A6 - postcard size) instead of labelling it a failure for not winning a present method IQ test.
The maximum image size capability of larger format Nikons and Canons would be easily observed, not hidden, (e.g. perhaps - capable of PQ up to A2 or A1).
It would helpfully aid comparison, not thwart it, by enabling buyers to apply their requirements to a meaningful statement of output delivery. Those who need an image size of 1.6 metres x 2.4 metres would quickly spot the camera for them. And as an appraisal method it would cast a whole new light on all the compacts out there too.
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Rob
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Photocracy
The Great Pretender
Reged: 18/11/2006
Posts: 493
Loc: Sunny South Coast
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Quote:
I think the new kit lenses were a step in the right direction. Good quality and pretty small, especially the 40-150mm which is not much bigegr than the standard zoom. Is there another lens of that size that gives an 35mm focal length of 300mm?
My E-500 body + 70-300mm lens will fit into a small bag about the size of a loaf of bread. In fact, it is small enough to attach to a belt via the loops provided. This offers me 'go anywhere' 600mm equivalent photography!
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Rob
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Benchista
Wich Tyler
Reged: 11/08/2000
Posts: 37017
Loc: Everywhere and nowhere, baby
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But who decides what's acceptable for each threshold?
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Nick
www.nbrphoto.com
Light and Shade II - the new blog
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Fen
BAD WOLF
Reged: 12/03/2002
Posts: 20174
Loc: Currently Unknown!
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Quote:
But who decides what's acceptable for each threshold?
The Olympus Users of course 
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Fen .......... My Galleries - My Blog - My Flickr
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Benchista
Wich Tyler
Reged: 11/08/2000
Posts: 37017
Loc: Everywhere and nowhere, baby
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Quote:
Quote:
But who decides what's acceptable for each threshold?
The Olympus Users of course
Just be grateful this isn't the insane asylum that is DPR Forums - you would be in REAL trouble for that sort of thing there!
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Nick
www.nbrphoto.com
Light and Shade II - the new blog
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beejaybee
Marvin
Reged: 18/07/2007
Posts: 4472
Loc: Really Here In Name Only
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Quote:
Should be easy to show the difference between large format and a digital compact but I don't expect the differences between APS-C and 4/3rds to be that great. I think it's more a theoretical advantage than a practical one that can be demonstrated.
Maybe slightly off topic in this forum but I have both Canon 40D and 5D bodies and definitely notice the difference in DoF when used with the exact same lenses. I'd expect the difference between APS-C and 4/3 to be very similar.
Edit: Just to point out that extra depth of field is not always a positive attribute....
Edited by beejaybee (02/07/2008 14:57)
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Photocracy
The Great Pretender
Reged: 18/11/2006
Posts: 493
Loc: Sunny South Coast
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Quote:
But who decides what's acceptable for each threshold?
Not each threshold as there would only be one which cameras would either pass or not i.e. capable of publishable quality(CPQ). The variable would be the maximum size at which CPQ still holds true. So, if applied presently, the larger format Nikons and Canons would still come off best, as indeed they should. But for example, instead of the Samsung GX20 scoring 85%, it might be given a rating of CPQ/A3. In other words, capable of publishable quality up to A3. This is a much clearer and more meaningful indicator of its ability for the buyer than 85%, which implies it's a lesser tool than all those scoring above it. The narrative of the review would be the place to discuss any particular strengths or weaknesses.
As for who decides, being in the business as it were, magazines and/or their reviewers are well placed to recognise publishable quality or otherwise. I don't think I'd have too much trouble agreeing with them.
If something is incapable of publishable quality at any size, like my camera phone for example, then it is a consumer snapper/toy/novelty with poor image quality. It would be good to know that too.
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Rob
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Photocracy
The Great Pretender
Reged: 18/11/2006
Posts: 493
Loc: Sunny South Coast
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Quote:
Quote:
But who decides what's acceptable for each threshold?
The Olympus Users of course
Now, now. You'll see that like 4/3rds, the proposal is an open standard!
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Rob
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