i used a half century old lens - the canon FL 55mm f/1.2, which i believe is reasonably close to symmetrical though not as close as the even older 58mm normals. i imagine m-lenses would show the effect you talk about to a much larger extent due to the closer flange distance. this is the one reason the m9 has offset microlenses. what you said was that µ4/3 can't do f/1.4, which i think is somewhat of a missrepresentation. i doubt µ4/3 can really do f/1.4 using a leica m summilux wide angle lens, but it seems to work just fine for me with normal length f/1.4 dslr lens.
theSuede wrote:
Sebboh:
If you try this with modern very retrofocal lenses, the effect is diminished by a large margin. With a higher retrofocal effect, angle of incidence to the sensor diminishes (even the aperture edge relative angles) - you distance the exit pupil from the plane of focus (the sensor).
But as we are in the "ALT" section, my example was using a standard lens like the nearly symmetrical Takumar 50F/1.4 or any other standard wider "alt" lens. Wide large-aperture Leica M-lenses usually give the worst aperture-to-exposure ratios of all.
ISO1600 wrote:
I for one, like to be able to control my DoF. You simply cannot do that on M4/3 (i will not call it MFT), nor can you do it on DX.
This simply shows your bias for preferring shallow DoF, and nothing else. Again, not everyone wants shallow DoF in their images. If I could buy a DX camera that had the noise performance of a D700, I would do so in a heartbeat. I spend a lot of my time operating at the fringes of high ISO performance and the D700 is a double edged sword. Even though I can use very high ISOs I'm still forced to shoot wide-open a lot of the time, and for certain kinds of shots shallow DoF is a big problem.
ISO1600 wrote:
Remember before the D3 came out? The "Canon look" was shallow DoF that we were getting with our bigger sensors. DX fans just didn't understand it.
Believe me, I understand all of it. I understand where FF benefits you, where DX benefits you and where MFT benefits you. I use all three and regard them as different tools for different jobs.
As far as "image quality" is concerned, I completely disagree. MFT has high image quality, just as most dSLRs do. The difference in DoF have been worked over ad nauseum, which only really leaves Dynamic Range (since its been proven conclusively that Panasonic's cameras are capable of rendering fantastic levels of resolution). Yes, MFT suffers there in comparison to FF cameras, but the difference in rarely an issue in my images. At the end of the day, a photographer who shoots RAW, knows how to expose correctly and knows how to use Lightroom is going to produce a better image than an inexperienced photographer shooting with a 5D in JPEG. The "image quality" that goes into the RAW file is just one piece of the puzzle. At the end of the day, I'm quite happy with the quality of the photographs I produce with the GF1 and have very few complaints.
theSuede wrote:
(...)
Try the F/1.4 lens at the 4/3 camera - first at wide open, and then at 1 stop down (F/2) and 2 stops down (F/2.8). Save the raw files.
Do the same, same lens mounted on a 5D (or any other FF/FX camera), or a Nikon D40 - also a very low MP/cm2 camera.
Use any available tool to check the raw-files. The FF/FX camera will show an almost perfect 1 stop difference between the files (if the aperture in the lens works as it should). The 4/3 camera will show less than 1 stop from F/2.8 to F/2, and considerably less from F/2 to F/1.4 - maybe 1/3Ev. If you have a F/0.95 lens nearby - by all means try it. You get NOTHING except more veiling flare by going from F/1.4 to F/1.0.... No increase in measured exposure. ...Show more →
I have done that, several times. As a part in learning a new lens I do some initial simple test images checking an old fashioned USAF chart, a flare setup and some simple initial bokeh tests.
I haven't found what you describe. Are you thinking of the corners only?
Since it has a hotshoe, is slightly bigger than the typical Olympus P&S, is smaller than the E-system digital SLR, either it's a new m4/3 or a fixed lens Olympus with a m4/3rds sensor
Can anyone explain why it is that the MFT camera (I refer to the EP-1), if set to capture a 60s exposure, requires an additional 60s of processing time during which the camera is unusable? I just recently discovered that, and found it annoying. Not nearly as annoying as ISO1600 might find it, but annoying just the same.
sounds like dark frame subtraction
look for a setting for NR (Noise Reduction, not the noise filter)
It might be set to ON by default (other E series SLRs are like that too)
it activates beyond 4 secs shutter speed if set to ON (I think, at least if it follows the pattern of the SLRs)
pascal03 wrote:
New Rumor... A 3rd Olympus m4/3rds on the way
Since it has a hotshoe, is slightly bigger than the typical Olympus P&S, is smaller than the E-system digital SLR, either it's a new m4/3 or a fixed lens Olympus with a m4/3rds sensor
It looks like something similar to the E300. Maybe a MFT version with built in EVF and a proper hand grip? Looks like the 17mm pancake lens is mounted on the tease camera from what I can see from downloading the pic and zooming in I can make out a "7" between the fingers of the hand. The lens does look allot like the 17mm pancake lens, so it looks highly likely that it will be another MFT camera rather then another normal FT model.
ISO1600 wrote:
why do you guys say MFT and FT? When was that settled on? I like how you'll say MFT or FT, then link to 43rumors.
the available options are µ4/3, u4/3, m4/3, MFT and mFT, for some reason back at the beginnings at dpreview µ4/3 was decided on, but quickly collapsed. Now we see all versions all the time. So there is no hard rule, however I think MFT is one of the unwisest choices.
I use mFT and 4/3rds, small 'm' so as not to confuse MTF for speed readers with dyslexia, ymmv
Lotusm50 wrote:
It's a little unclear to me. When I see "MFT" I think of manual focus. "m4/3" is much more immediately recognizable and clear in its representation.
Agreed- I go one step further and imagine people using an EP1 and such with manual focus lenses.
Rob Riley wrote:
the available options are µ4/3, u4/3, m4/3, MFT and mFT, for some reason back at the beginnings at dpreview µ4/3 was decided on, but quickly collapsed. Now we see all versions all the time. So there is no hard rule, however I think MFT is one of the unwisest choices.
I use mFT and 4/3rds, small 'm' so as not to confuse MTF for speed readers with dyslexia, ymmv
Totally agree that it should be µ4/3. The reason to why I don't use it is that I don't know how to type the µ (now I just copied yours ).
I was a physics student at the University and don't like mFT and m4/3. For me "m" means "milli".
MFT feels better, because it's just short for Micro Four Thirds. Just like the normal way of abbreviation.
HelenaN wrote:
Totally agree that it should be µ4/3. The reason to why I don't use it is that I don't know how to type the µ (now I just copied yours ).
Yes, exactly. It's more difficult to type, and most don't know how to access the "µ" character. That's why I would opt for the small "m".
I usually use µ4/3. I understand most go with m4/3 as typing an "m" is just one click. For a Windows system the µ is typed by pressing the Alt button, holding it while on the numerical part of the keyboard pressing 0181 and then let go of the Alt button. It takes a stubborn sort of person to keep up with that and I guess it fits me.
Writing milli four thirds when it should be mikro four thirds doesn't appeal to me. MFT is an abbreviation but unfortunately possible to mix up. But then again, they all are.
Had there been anything to vote for I would vote µ4/3 or MFT.
Jonas B wrote:
theSuede: Please check my reply above. Thank you.
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I usually use µ4/3. I understand most go with m4/3 as typing an "m" is just one click. For a Windows system the µ is typed by pressing the Alt button, holding it while on the numerical part of the keyboard pressing 0181 and then let go of the Alt button. It takes a stubborn sort of person to keep up with that and I guess it fits me.
if anyone is wondering how to do this on a mac, you simply hold down the option key as you type the m key to get a µ symbol.
Rob Riley wrote:
the available options are µ4/3, u4/3, m4/3, MFT and mFT, for some reason back at the beginnings at dpreview µ4/3 was decided on, but quickly collapsed. Now we see all versions all the time. So there is no hard rule, however I think MFT is one of the unwisest choices.
I use mFT and 4/3rds, small 'm' so as not to confuse MTF for speed readers with dyslexia, ymmv
Jonas: Most F/1.4 lenses stop down more than they "should" to the F/2 and above apertures. If you don't have the equipment to measure exact aperture, comparison to another fix-focal of the same FL, but with F/2.8 hard aperture (a macro maybe?) may confirm this. I measured with a lens with controlled aperture values - controlled with a point collimator I "borrowed" from the mech. guys, normally used for non-contact QC measurements - and compared the results to my own D700 and a 1Ds3. I did this quite elaborately as the main reason for the little excursion was to measure the 85L and the Nikon 85/1.4AFD lenses (F/1.26 and F/1.42 at infinity).
exact values for G-1 and E-20: F/2.8=0, F/2.0>-0.2, F/1.4>-0.55
exact values for D700: F/2.8=0, F/2.0>-0.1, F/1.4>-0.2
Now if we suppose that my aperture-measurement was totally wrong, and that the behaviour of the lens on the D700 is "perfect" (highly improbable!) the "comparative" loss compared to a larger cell camera was:
-0.1Ev to F/2.0 and -0.35Ev to F/1.4. But those values are most certainly way to optimistic.
Losses were measured from linear raw ADU, not by eyeballing exposure compensation in a raw-converter. Newer sensors may of course be better, but in that case it's probably a small step, nothing drastic. I'd like to test the GF1 that has a totally new construction in the toppings... But I doubt we'll see any drastic performance increase in angle efficiency in <4um sensors until BSI is commersially valid for sensors larger than 8mm. That may take a while.
One aspect of angle loss is that once it is high enough to be detected in a picture, 10º later the signal is almost dead. Kodak has some data on their sensors, but otherwise manufacturer data for sensors larger than compact modules are hard to come by. Kodak pulled the KAF18500 data (Leica M9), even from the more inaccessible parts of the site - probably after a Leica request. Angle loss in the M9 can cause -2.5-3Ev vignetting (!) and strong colour bleeds with some WA's. This is the previous model 4/3 sensor: http://www.kodak.com/global/plugins/acrobat/en/business/ISS/datasheet/interline/KAI-10100LongSpec.pdf
I remember seeing a comparison of the influence of microlenses on angle-loss in another Kodak document, but I can't find it right now. In short: no microlens assembly gives low overall efficiency, but almost no angle loss. "Strong" microlens assembly gives up to a doubling of head-on efficiency, but -2Ev at 30-35º angles.
Another "fun" experiment if you like this kind of thing is to do the angle loss measurement with a 532nm laser in stead - when you do this you can also see the definitely not negligeble colour bleed as blue and red channels increase in strength as you increase the angle of the (very pure) green light.
