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Author Topic: Seriously considering upgrading my E1  (Read 15082 times)
Ray
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« Reply #40 on: July 14, 2006, 08:07:52 PM »
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I damn well guarantee that the 135/2L is going to have a significantly higher MTF at 56 lp/mm than a 100-400L + 1.4xTC.

Of course it is. But I damn well guarantee that my 100-400 with or without extender will capture more detail of any target, from the same distance, than your 135/2L.

By the way, according to Photodo tests, the 135/2 is sharpest at f8, same as the 50/1.4 which has identical ratings at f8 and which is the lens used in Dpreview resolution tests.

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The sensor resolution of the D60 is about 45 lp/mm

Jonathan, life in the army seems to be having an effect on your grasp of photographic facts. The sensor resolution of the D60 is similar to that of the 1Ds2. I think you are confusing total picture resolution with absolute resolution. The sensor with the higher pixel count, whatever its size, almost always delivers a higher total picture resolution. The Nikon D2X is on a par with the 1Ds because it has a similar pixel count, even though the sensor sizes are different. There are 8mp P&S cameras that produce picture resolutions equal to the latest 8mp Olympus 4/3rds systems.

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If you're basing your perception of sensor resolution off the results you're getting with the 100-400L + 1.4X TC, I guarantee you'll be pleasantly surprised at how much better results you can get with better glass.

There's no argument that better glass does not produce better results. I merely thought it was noteworthy that at an aperture of f22 even, the 20D can produce a higher 'absolute' resolution (line pairs per mm) than the 5D with the same lens.

I think you've clearly missed my point, haven't you?
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Ray
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« Reply #41 on: July 14, 2006, 08:27:17 PM »
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Oh no, Ray's crystal ball is back, and yet again it predicts Olympus failing to adequately improve its products, while Canon succeeds in overcoming its current limitations. [a href=\"index.php?act=findpost&pid=70717\"][{POST_SNAPBACK}][/a]

Yes. Predictions are often possible given sufficient facts. Your partisan approach (as opposed to my completely unbiased approach) would lead me to believe you actually own an Olypus E1 and are supporting it as one might support a football team. Is this correct?  
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BJL
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« Reply #42 on: July 15, 2006, 03:29:27 AM »
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Yes. Predictions are often possible given sufficient facts.
[a href=\"index.php?act=findpost&pid=70732\"][{POST_SNAPBACK}][/a]
Facts that were noticeably missing from your prediction!
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Jonathan Wienke
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« Reply #43 on: July 15, 2006, 07:43:42 AM »
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Of course it is. But I damn well guarantee that my 100-400 with or without extender will capture more detail of any target, from the same distance, than your 135/2L.

Only if the 100-400 is set to a focal length > 135mm, and you crop pixels from the 135/2L frame to get the same coverage. But if you set the focal length such that you capture an equal pixel count and equal FOV with both lenses, the 135/2L will beat the 100-400L hands-down, and the higher the camera resolution, the more pronounced the difference will be.

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Jonathan, life in the army seems to be having an effect on your grasp of photographic facts. The sensor resolution of the D60 is similar to that of the 1Ds2.

The lp/mm figures I cited were derived from the horizontal pixel count (4064 for the 1Ds) divided by sensor width (36mm for the 1Ds and all other "full-frame" cameras), then dividing that number by 2, since you need at least two pixels to record a line pair: (4064 / 36) / 2 = 56.44 lp/mm. But I transposed some digits when calculating the D60; the correct figure is 67.67 lp/mm.

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There's no argument that better glass does not produce better results. I merely thought it was noteworthy that at an aperture of f22 even, the 20D can produce a higher 'absolute' resolution (line pairs per mm) than the 5D with the same lens.

Well obviously, because 20D sensor can record up to 77.87 lp/mm, and the 5D sensor can only record up to 60.67 lp/mm. But that's not what we're disagreeing about; the premise I take issue is that sensors are the weakest link when it comes to resolution performance. If you compare the MTF of any current DSLR sensor at its maximum spatial frequency (56.44 for the 1Ds, 60.67 for the 5D, etc.) to the MTF of any currently available lens at the same lp/mm, the sensor MTF will be higher than the lens MTF in all but a very few cases.
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Ray
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« Reply #44 on: July 15, 2006, 08:46:45 AM »
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Only if the 100-400 is set to a focal length > 135mm


Of course! That's why we use zooms. The finest prime ever made is not much use if it's not the right focal length for the job.

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(4064 / 36) / 2 = 56.44 lp/mm. But I transposed some digits when calculating the D60; the correct figure is 67.67 lp/mm.


Have you already forgotten those threads discussing the merits of the Foveon sensor? Only the Sigma SD9 & 10 can reach the Nyquist limit of one pixel per line width, which is why a 3.3mp Foveon sensor has almost the same resolution as a 6mp Bayer type.

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If you compare the MTF of any current DSLR sensor at its maximum spatial frequency (56.44 for the 1Ds, 60.67 for the 5D, etc.) to the MTF of any currently available lens at the same lp/mm, the sensor MTF will be higher than the lens MTF in all but a very few cases.


That's not the impression I get. Norman Koren has tested his Canon 10D and produced a graph of the 'system' MTF (sensor plus lens) across all frequencies the sensor can record. Maximum resolution, as I recall, is around 54 lp/mm at 10% MTF. Any perusal of the Photodo MTF charts at 40 lp/mm will give you an indication of what the MTF response at a few lines greater resolution is likely to be. If it's mostly well above 50% at 40 lp/mm (and sometimes above 60%), it's likely to be not much below 50% at 54 lp/mm, let's say 45%.

I don't know how we get a combined MTF response of 10% (at 54 lp/mm) from a lens delivering around 45% (at 54 lp/mm) if the sensor is not the weaker link.
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Jonathan Wienke
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« Reply #45 on: July 15, 2006, 09:04:25 AM »
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Post a link to Koren's tests; I'd like to see how he came up with his results. 10% MTF sounds suspiciously low to me.

The only difference between Bayer and Foveon sensors is that Bayer sensors' MTF starts falling off sooner than Foveon when approaching Nyquist because of the anti-aliasing filter. Both sensors can record detail at the Nyquist limit, the Bayer sensor will have an MTF of 50-70% (depending on the AA filter, this was discussed in another recent thread regarding one of the new MF backs), while the Foveon will be closer to 100%. IMO the resolution advantage of a Foveon is more like 33% than the 100% that the Foveon enthusiasts would like people to believe.

I don't know why so many people bother to use Zeiss and other third-party lenses on Canons if the sensor was the weakest link. My experience (and that of most other photographers) is that with cameras 8MP on up, the lens (even when using L glass) is the greatest degrader of resolution unless one is using primes.
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Rob C
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« Reply #46 on: July 15, 2006, 10:18:26 AM »
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Situgrrl

Interesting name - do you have a dog that you are training to sit down on command?

However, photography: I resisted digital for a long time, eventually deciding that I might as well give it a bash. Being a Nikon camera devotee since the F, and already having manual Nikkors (avoided autofocus even when I had an F4s), I settled for the D200.

It opened my eyes. It also hunched my back, as my time at the computer has gone from normal (whatever that is) to absurd.

I don't think you might need to shoot at high ratings as much as you think you do - I use the lowest rating available of 100, always RAW/NEF; the quality from these primes is quite remarkable at apertures much wider than I would previously have though to use on film, mainly because the altered perceptions of depth of field with smaller capture areas changes everything.

Yes, I was already in the Nikon system, but speaking from a practical point of view, if the results work for me, then that's all there is to it. There is so much internet chat about different marques, primes v. zooms etc. that confusion must reign supreme in the mind of anyone starting out in photography.

My advice is this: decide on a format; buy the most expensive body you can afford and a single lens at the limit of your budget. Make that lens the equivalent to a 35mm on full-frame 35mm film cameras (in the case of the D200 that means a 24mm lens).  Experiment like hell and don't rush into buying lots of glass that will often end up gathering dust. I speak as a pro and I've done just that, to my shame, as has every other pro I've known!

Once you know what the single camera/lens can really do, which takes time, only then think about more equipment. Incidently, I would suggest buying new; used might be good too, but you can't know before you buy and then it's too late. A poor camera/lens can seriously impair your learning and, importantly, expectations.

Ciao - Rob C
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Ray
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« Reply #47 on: July 15, 2006, 10:20:12 AM »
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I don't know why so many people bother to use Zeiss and other third-party lenses on Canons if the sensor was the weakest link. My experience (and that of most other photographers) is that with cameras 8MP on up, the lens (even when using L glass) is the greatest degrader of resolution unless one is using primes.
[{POST_SNAPBACK}][/a]

I've never seen any MTF curves for a sensor as we used to get for film types, but it was well known that increasing the performance of a lens with film did not produce a proportional increase in image quality. There's always some increase in quality, however. Since it's not possible to change sensors as one used to be able to change film quality, the only possibility for improved performance is to use a higher grade lens or buy a new body.

I've found the Norman Koren page that shows the 10D test results.

[attachment=821:attachment]

Address [a href=\"http://www.normankoren.com/EOS-10D_3.html#Res_vs_35mm]here[/url]
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Ray
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« Reply #48 on: July 15, 2006, 10:42:05 AM »
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Facts that were noticeably missing from your prediction!
[a href=\"index.php?act=findpost&pid=70744\"][{POST_SNAPBACK}][/a]

BJL,
If I don't provide facts it's because I can't find them. All I can do is make a few guesses and deductions from the fragments of information available. Since the 8mp Olympus 4/3rds cameras have no greater resolving power than the 8mp Canon DSLRs (and apparently slightly less, or at least some problems with moire), I think we can assume that the 4/3rds sensor is in the same situation as the the Canon Bayer type, ie. it takes approx 2.5 pixels or more for each line pair. Looking at the specs of the E-330, I deduce an absolute resolution of 72 lp/mm.

I believe dpreview use the Zuiko ED 50/2 to test the Olympus cameras. The MTF response for this lens appears to be an impressive 60-65% at 60 lp/mm. No figures available for 72 lp/mm. Would 50% be a good guesstimate?

Lens delivers 50% contrast at 72 lp/mm. Sensor delivers 10%.
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BJL
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« Reply #49 on: July 17, 2006, 08:02:24 AM »
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Since the 8mp Olympus 4/3rds cameras have no greater resolving power than the 8mp Canon DSLRs
[a href=\"index.php?act=findpost&pid=70777\"][{POST_SNAPBACK}][/a]
Nonsense. I see absolutely no basis for your claim of 10% sensor resolution, working at 72lp/mm where you have no data for either lens or lens+sensor resolution, for which you substitute guesses.
Can you explain how you get from your guess of 50lp/mm for the lens to 10lp/mm for the sensor?

Your whole argument seems nicely summarized by your first line
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... I don't provide facts ... because I can't find them

The DPReview tests give some rough resolution measures, which can be converted from "lines per picture height" back to line pairs per mm as follows: take the l/ph value, divide by the frame height listed in the review, and divide by two to get back from "lines" to line pairs.

The result is clear and unsurprising: the E-300, E-500 and E-330 all outresolve any of Canon's sensors, falling just slightly short of the D2X; all more or less as you would guess from pixel spacing. For example, 64-69lp/mm for the E-500, 55-63 lp/mm for the 20D.
Likewise, the E-1 outresolved any other DSLR on the market at that time.

Ironically, Canon's DSLR sensors now seem to trail those of Sony, Kodak and Panasonic for lp/mm resolution, though I expect a partial comeback soon with something like a 10MP+ EF-S format model. So how do you come to your conclusion that Canon (rather than Sony even) is the place for Olympus to turn for higher DSLR sensor resolution, as in these words:
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... to get this 4/3rds system to fly requires a marriage between a sensor manufacturer that has a performance edge (such as Canon) and a lens manufacturer with a performance edge (such as Zuiko).

I am happy to accept your verdict on lenses though, as someone what has repeatedly chosen SLR systems (Canon film then Olympus digital) largely on the basis of the quality of the lens offerings in my price range.
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Ray
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« Reply #50 on: July 17, 2006, 10:06:27 AM »
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Nonsense. I see absolutely no basis for your claim of 10% sensor resolution, working at 72lp/mm where you have no data for either lens or lens+sensor resolution, for which you substitute guesses.


The figure of maximum sensor resolution of 72 lp/mm was derived by dividing the total number of pixels on the E-330's sensor (long dimension) by 2.5. But I see I've been over-generous because the true resolution is 64-69 lp/mm. Of course I now realise I should not have used the term 'resolving power' when I wrote, 'The Olympus 4/3rds cameras have no greater resolving power than the 8mp Canon DSLRs.' I meant of course, total picture resolving power. I'm surprised you did not gather this from the context   .

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Can you explain how you get from your guess of 50lp/mm for the lens to 10lp/mm for the sensor?


BJL,
Now you're confusing lp/mm with contrast percentages. The MTF chart on the Olympus site shows the Zuiko 50/2 as having an MTF response ranging between 65% and 60% at 60 lp/mm. I therefore think it a reasonable guess that MTF at 72 lp/mm would be around 50%. But now we know the true resolution is no more than 69 lp/mm, I would think 50% would be a conservative estimate.

10% MTF (not 10 lp/mm) is the contrast at the cut-off point of 69 lp/mm. Lens delivers 69 lp/mm at 50% MTF, at least. Sensor delivers 69 lp/mm at 10% MTF, at most. Ergo, the sensor is very much the weak link.

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Ironically, Canon's DSLR sensors now seem to trail those of Sony, Kodak and Panasonic for lp/mm resolution


Maybe. I'm not terribly concerned about a few lp/mm here or there. For me, low noise at high ISO is more significant. If the 20D was better than the D60 only in respect of having 8mp instead of 6mp, I wouldn't have bought it. If the 20D was only a 6mp camera but with the stirling noise performance it has at ISO 1600, I would still have bought it.
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BJL
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« Reply #51 on: July 17, 2006, 10:44:53 AM »
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10% MTF (not 10 lp/mm) is the contrast at the cut-off point of 69 lp/mm. Lens delivers 69 lp/mm at 50% MTF, at least. Sensor delivers 69 lp/mm at 10% MTF, at most.
[a href=\"index.php?act=findpost&pid=70936\"][{POST_SNAPBACK}][/a]
Firstly, I see no source for this 10% figure (yes, %, not lp/mm!).
Secondly, I do not see why I should care about MTF as this particular number of 69lp/mm, just below the Nyquist-like limit from pixel size. At the very useful 60lp/mm level, there is no sign of such extremely low sensor MTF. Let alone the possibly more relevant 20lp/mm.
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Ray
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« Reply #52 on: July 17, 2006, 08:10:42 PM »
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Firstly, I see no source for this 10% figure (yes, %, not lp/mm!).


Again I'm making some deductions which I think are reasonable in light of the few facts on such matters that are available. Refer to the Norman Koren tests of the 10D here

First, 10% seems to be a general (practical) cut-off point for visible resolution. Anything less seems to be irrelevant except for the most demanding scientific purposes. The Rayleigh's limit for lens resolution at a diffraction limited aperture is a case in point. Secondly, the 4/3rds sensors are Bayer type like the Canon sensors, aren't they? We might therefore expect the combined lens/sensor MTF curve to be very similar to that of the 10D's sensor, as illustrated on the NK site. One would expect only the lp/mm figures to change. 10D's resolution limit is 55 lp/mm at 10% MTF; E-330's resolution limit is 69 lp/mm at 10%.

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Secondly, I do not see why I should care about MTF as this particular number of 69lp/mm, just below the Nyquist-like limit from pixel size. At the very useful 60lp/mm level, there is no sign of such extremely low sensor MTF. Let alone the possibly more relevant 20lp/mm.


If you make prints no larger than A4, are not in the habit of cropping your images and are not short-sighted, there's probably not much reason to care about sensor MTF at 69 lp/mm. On the other hand, given a certain amount of altruism, you might consider the concerns of other viewers who happen to have keener eyesight than yours   . Neither the E-330 nor 20D can meet that rigorous standard of 6 lp/mm on an A4 print.

If you have a large printer such as the 24" wide Epson 7600, as I have, then maximum print size increases by a factor of 3 in each dimension. I would therefore think (at least it's a logical proposition if not supported by empirical evidence) that the role played by 10 lp/mm on an A4 size print (regarding SQF), becomes 30 lp/mm and the role played by 20 lp/mm becomes 60 lp/mm on a 24x36" print, for close inspection purposes.

Of course, if you bring in the factor that large prints have a 'normal' viewing distance which is also greater, then it's an entirely different ball game. It can be impossible to tell the difference between a 35mm blow-up and an MF blow-up from across the room. But close inspection reveals all.
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ddolde
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« Reply #53 on: July 17, 2006, 10:23:15 PM »
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Wanky ain't you dead yet?  The Army is dangerous man.  W. will have your head on a platter.
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BJL
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« Reply #54 on: July 18, 2006, 08:27:06 AM »
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... First, 10% seems to be a general (practical) cut-off point for visible resolution. Anything less seems to be irrelevant except for the most demanding scientific purposes. The Rayleigh's limit for lens resolution at a diffraction limited aperture is a case in point. Secondly, the 4/3rds sensors are Bayer type like the Canon sensors, aren't they? We might therefore expect the combined lens/sensor MTF curve to be very similar to that of the 10D's sensor, as illustrated on the NK site.
[a href=\"index.php?act=findpost&pid=70978\"][{POST_SNAPBACK}][/a]
So the bottom line is that the sensor in the E-500 and E-300 has slightly lower pixel count/resolution than that in the 20D and 350D, so that by choosing a resolution level that is a bit beyond the E-500 sensor but within the reach of the 20D sensor, the 20D is likely to give higher MTF. And from that you deduce that the FourThirds system is hopeless behind in sensor technology, solvable only by changing to Canon's sensor (and perhaps to Canon's format choices).

That is certainly a lot to read into the differences in the very small differences in the resolution numbers I have seen! DPReview gives the 20D and 350D 1850 horizontal LPH vs 1800 or 2.7% less for the E-500, while both are measured at 1650 vertical LPH. The piel counts also differ by equally small amounts: 5% more vertical for the E-500/E-300 than the 350D, 6% more horizontally for the 350D. Noting that DPReview's LPH numbers are always multiples of 50, reflecting the precision of the measurements, you base you entire condemnation of the FourThirds sensors on a single step (of less than 3%) in a single resolution measurement!
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Jonathan Wienke
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« Reply #55 on: July 18, 2006, 12:39:21 PM »
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Wanky ain't you dead yet?

The rumors of my demise are greatly exaggerated.
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Ray
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« Reply #56 on: July 18, 2006, 09:06:48 PM »
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So the bottom line is that the sensor in the E-500 and E-300 has slightly lower pixel count/resolution than that in the 20D and 350D, so that by choosing a resolution level that is a bit beyond the E-500 sensor but within the reach of the 20D sensor, the 20D is likely to give higher MTF. And from that you deduce that the FourThirds system is hopeless behind in sensor technology, solvable only by changing to Canon's sensor (and perhaps to Canon's format choices).

BJL,
You're putting words in my mouth. I don't see the 4/3rds system as hopeless. It has the advantages of being slightly cheaper and lighter than 'the next size up' Canon. It has almost the same resolution, as close as matters for non-pixel-peepers except perhaps for a tendency to produce moire effects, but as a total package it is lacking in certain desirable features such as Image Stabilisation and low noise at high ISO's. In other words, performance is hampered by the precise factors that give the camera its only advantages of slightly lower cost and weight.

As I wrote many posts ago, for the 4/3rds system to really fly, it needs a ground-breaking sensor design to match the quality of its lenses, otherwise it will always trail its slightly bigger brother in total image quality. It might occasionally catch up resolution-wise, might even marginally exceed its Canon competitor briefly by being first to cram more tiny pixels on its tiny sensor, but ultimately, unless it can match Canon's low noise and over all image quality, it will remain in a niche market.

But there's nothing wrong with that. Niche markets should be catered for. If money was no problem, I'd probably buy an Olympus E-500, 300/2.8 lens plus 1.4x extender, provided I could first see some comparison shots between that combination and an equivalent Canon combination of similar weight. In other words, without cost being a considerations, does (say) 4Kg of Olympus gear get me a sharper (and better quality image noise-wise) of that tiny bird 20 metres away, than 4Kg of appropriately chosen Canon gear, without being too concerned about a few grams either way?

That's probably another question that cannot be answered by any readily available facts, leaving me to just speculate and make reasonable deductions, as I've been doing all along. The Olympus 4/3rds format was supposed to be 'taking on' the 35mm format. I don't see much in the way of image comparisons on the net.
« Last Edit: July 18, 2006, 09:23:15 PM by Ray » Logged
Ray
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« Reply #57 on: July 18, 2006, 09:12:36 PM »
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The Army is dangerous man.  W. will have your head on a platter.
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Doug,
You really should get back on your medication.
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BJL
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« Reply #58 on: July 20, 2006, 03:50:59 AM »
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BJL,
You're putting words in my mouth. I don't see the 4/3rds system as hopeless.
[a href=\"index.php?act=findpost&pid=71078\"][{POST_SNAPBACK}][/a]
My comment was only about your criticisms of FourThirds sensor technology, not FourThirds as a whole, and on that point you again seem to insist that FourThirds needs a major improvement, or else will become a niche product. (How do you define "niche product"? Less than 3% share of the DSLR market, as is the case with 35mm format?)

As to high ISO, you have heard my answer many times: how high an ISO speed is needed is related to the minimum usable f-stop, and smaller formats with their shorter focal lengths can typically use lower f-stops, and thus lower ISO speeds to get the same shutter speed in given lighting conditions. Comparisons at equal ISO are rarely relevant, because they assume that the larger format can use a lens that is likely to be bigger and heavier (longer focal length, larger aperture diameter, larger front elements), if such a lens exists at all. Such comparisons also either ignore the lower DOF in the larger format at equal f-stop, or dubiously assume that the extremely shallow DOF of a fast lens used wide open is never a disadvantage to image quality.

For all but the users of the extremes of large aperture lenses (f/1.4 or f/1.2 primes etc.), Four Thirds can match the noise levels of a larger format like EF-S at a given high shutter speed/low light level combination by using lenses of the same FOV and same aperture diameter. In comparison of FourThirds to EF-S format, this means focal length about 10-20% less and aperture ratio about 1/2 stop less. That allows using ISO speed about 1/2 stop lower, which with comparable sensor technologies should give about the same noise levels.

Since FourThirds is capable of reaching f/1.4 in primes and already has one constant f/2 zoom, EF-S only gains a true high speed advantage over the FourThirds lens system at apertures below about f/1.7 in primes and f/2.4 in zooms. Or if most FourThirds lenses stay at f/2 and smaller, as seems likely, the threshold is f/2.4 across the board. (And about f/2.5 compared to DX format.)
As far as I know, since DSLR's arrived, the four main SLR makers other than Olympus have introduced only one new lens faster than f/2.8, the Nikon 200/2, so it seems to me that most of the APS-C format DSLR world is working within that f/2.4 limit. (The 85/1.2 II is an update of a rather old design, not a new design.)
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Ray
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« Reply #59 on: July 20, 2006, 10:59:50 AM »
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Four Thirds can match the noise levels of a larger format like EF-S at a given high shutter speed/low light level combination by using lenses of the same FOV and same aperture diameter. In comparison of FourThirds to EF-S format, this means focal length about 10-20% less and aperture ratio about 1/2 stop less. That allows using ISO speed about 1/2 stop lower, which with comparable sensor technologies should give about the same noise levels.


You're exaggerating, BJL. The 4/3rds sensor is 18x13.5 as opposed to the 20D's 22.5x15. Comparing heights, the 4/3rds system has less than 1/4 stop DoF advantage. Comparing widths it has a full 1/4 stop DoF advantage. That puts it well behind the 20D noise levels which, according to dpreview are equivalent at ISO 800 to the 20D at ISO 2000. I'm comparing here both the E-500 and E-300 with the 20D. Image quality and noise at ISO 800 are on a par with the image quality and noise levels of the 20D at ISO 1600, which is actually ISO 2000. That's a 1 and a 1/4 stop difference. Regarding noise at the same Dof and at high ISO's the 20D has a one stop advantage. Add IS to that and in certain circumstances that advantage becomes 3 stops.
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