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Pana/Leica 12mm f/1.4 coming
#31
Anyhoo...

Could be a sweet combo between the 12/1.4 and 25/1.4 Leica lenses on an Olympus body with IBIS. Again, I care not a bit about getting the least possible DOF - I'm having enough problems with it as it is, to the point of preferring f/6.3ish aperture on my 16-35/4 (not for the lack of sharpness - this lens seems extremely sharp already wide open) even indoors - but getting some large aperture stuff for the situations when the light is dim would be great. And if they're small and lightweight... well, I got used to carrying the 1D with me every day but sometimes I just plain get tired of it. Getting the 70-300 zoom alongside the 70-200 was an act of desperation in this regard.

 

Speaking of wide apertures... the Canon 24/1.4 L is not terribly sharp wide open anyway. If I absolutely have to use it wide open (and not at f/1.8~f/2.2 as I prefer), I better hope that an interesting subject is worth the sacrifice in sharpness, and/or can mask it somehow... For amateur astro shots (and I'm an amateur at astro) it may do, but it's becoming obvious that the coma is pretty bad, AND I could only get either the fortress or the stars in focus, but not both (unless I'm getting into some veritable voodoo with focus stacking, blending and whatnot - and I'm not quite there yet).

[Image: iaxmEUSRJm4.jpg](24mm f/1.6)

P. S. Per the Cameralabs evaluation, the new 12mm looks quite a bit better than the 12/2 and the 7-14/2.8 at the overlapping apertures (duh). And f/22 looks... ugly.

#32
Yeah, f22 is supposed to look ugly. Diffraction, courtesy of physics. That is f44 in FF terms!

#33
Quote:Yeah, f22 is supposed to look ugly. Diffraction, courtesy of physics. That is f44 in FF terms!
I wonder why the cameras (mine, anyway) are rated down to f/91.  Wink
#34
Quote:Uhmm, no. Here you are confusing your fantasy with my facts again. Yes, fantasy is written with an F.  Wink

Evidence of what? I already gave you the calculations (= evidence B) ) to show you that indeed, 12mm f1.4 on MFT is equivalent (as equivalent as things can be with different aspect ratios) to 24mm f2.8 on full frame 135 format. What more "evidence" do you require?

And you have the odd idea that it is in any sense valuable to use the same ISO number setting on different cameras. No idea why you think that is in any way meaningful.

Nor is it meaningful to use the same f-value, as the f-value stands for apparent aperture size. Which means that you oddly enough place importance of setting one camera a f/1.4 where f = 12mm and the other camera at f/1.4 where f = 24mm. So you find it meaningful/logical to set one camera at 12 / 1.4 = 8.5mm aperture, and the other at 24 / 1.4 = 17mm aperture.


Yeah, that makes so much sense. Well actually, it does not, and never has.


So, not only does the f1.4 not mean the same on the different lenses, and does for instance "ISO 100" not have an actual significant meaning or importance, you end up with very different images due to the different DOF. How interesting to keep on repeating that useless "comparison".

 

Why not compare 50mm f1.4 on MFT to 50mm f1.4 on FF? You will find that with the same ISO number setting you will get the same exposure time when using a similar exposure metering method. 

 

Or how about putting a 500mm f8 lens on a Nikon D700 at ISO 3200 and a 20mm f1.4 lens on a Nikon D5 at ISO 100. Again, similar exposure times. Now you not only have different DOF, but also different FOV!

 

It is not that hard to come up with pretty senseless comparisons  :lol:
 

BC is correct.

 

Here is a good article from LumoLabs explaining camera equivalence.

I recommend anyone interested in the subject to read it:

http://www.falklumo.com/lumolabs/article...alence.pdf
--Florent

Flickr gallery
#35
I never said anything else than f/1.4 remains f/1.4, no matter which sensor behind. It leads at equivalent lenses nonetheless to the same shutter time, at given ISO and same lighting / exposure method. BC, I have no idea from what you get your idea of 12 and 24 mm lenses, none of them as used in the comparison. But reading superficially is enough for someone who already owns his truth.

 

So I will continue to think "blurbing again" when you're doing your thing. Trouble is, you never ever got the point of what I was saying. And neither do you, thxbb12. Especially with a general "BC is correct" to a pretty polemic post. Disappointing.

#36
Quote:I never said anything else than f/1.4 remains f/1.4, no matter which sensor behind. It leads at equivalent lenses nonetheless to the same shutter time, at given ISO and same lighting / exposure method. BC, I have no idea from what you get your idea of 12 and 24 mm lenses, none of them as used in the comparison. But reading superficially is enough for someone who already owns his truth.

 

So I will continue to think "blurbing again" when you're doing your thing. Trouble is, you never ever got the point of what I was saying. And neither do you, thxbb12. Especially with a general "BC is correct" to a pretty polemic post. Disappointing.
Oh gosh.

 

So I use the original (for this thread) focal lengths, and already you say I am not following your nonsense comparison? What makes the APS-C/FF comparison so different from the original 12mm MTF/24mm FF comparison?

 

And yes, BC is correct. You may find that disappointing, but it is just a fact.
#37
Oh, swanky. This thread has been officially ruined. But such is the fate of every damn Âµ4/3 thread here.

 

I'm outta here. -_-

#38
Posted twice somehow

Gear: Canon EOS R with 3 primes and 1 zoom, 4 EF-R adapters, Canon EOS 5 (analog), 9 Canon EF primes, a lone Canon EF zoom, 2 extenders, 2 converters, tubes; Olympus OM-D 1 Mk II & Pen F with 12 primes, 6 zooms, and 3 Metabones EF-MFT adapters ....
#39
Quote:That, of course, is incorrect.


It is very valid for light.


An equivalent focal length, gives the same field of view.

An equivalent f-stop setting, gives the same depth of field.

An equivalent ISO setting, gives the same amount of light.

The "only" part is nonsense...

The whole single reason it is "related to sensor noise" is because equivalent ISO settings will form the image with the same amount of light.

Because you used the same amount of light.


Light per square area size is.... totally not interesting in any way. The paradigm has shifted going from film to digital. With film, when using the same film, it made some sense. When using two totally different films, not so much.

ISO is not based on amount of light per square mm. You made that up... Or just misunderstood things that way.
https://en.wikipedia.org/wiki/Film_speed#Digital
 

Iso: you're talking about something completely different, namely iso sensitivity of a sensor - that is totally irrelevant here.

 

Iso, to spell it out a little more than I did before, originally indicated film sensitivity, and with a certain iso and EV value comes a certain aperture and shutter speed range which is totally and utterly independent of the sensor, medium, or film size. You appear to say that it is not - well you're wrong. In short, it is related to the sensitivity of the medium and the related EV of the scene one is trying to photograph, whether the iso is artificial or not (in a way it is artificial with a sensor, other than base iso, but then, we could push film as well, be it much less so than a sensor base iso).

 

And this is entirely due to the fact that we are talking about standard quantities of light  per standard unit as measured and used, with a measured EV and a set iso.

 

This has absolutely nothing to do with "equivalent iso". All that is important (if noticeable) is equivalent noise. And that is relevant, because to get the same magnification going from 4/3 to FF you need a 2x linear magnification, based on the light captured, which due to the actual size is 4x less, and hence carries 4x the noise, or two stops. That is the only "iso equivalence" that exists, and it really is noise equivalence, not iso equivalence. If we made the 4/3 sensor 4x bigger, same size area wise as a FF sensor, the noise would be the same.

 

In short:

- f-stop equivalence only has to do with DoF at the same size of print or image, but in effect is directly related to the real FL

- FL equivalence only has to do with the size iof the recording medium, film or sensor size, and is directly proportional to the crop factor

- iso equivalence when used as an amount of light is actually light units per square area units, because that is how light affects f-stop and shutter speed, not total amount of light per sensor or film size - using iso as total amount of light is incorrect in this regard

 

"noise equivalence", as I called it, depends on printing or displaying an image at the same size, and that is indeed influenced by sensor size, because a smaller sensor requires larger magnification to get to the same image size, and therefore will display more noise directly in proportion to the magnification and total amount of light received: (area in standard units) * (light units) received / (standard area unit). This is the only time total light received comes into the equation.

 

The latter, because we are talking quantities of light, we can express in f-stops, and hence in isos. All conditions staying the same, a 4/3 sensor receives a quarter of the TOTAL light of a FF sensor, and the image needs to be enlarged 2x linear (or 4x in area) to give the same image. This means that for the same size image a 4/3 sensor receives 2 stops less light than an FF sensor, which could be expressed as two iso grades, e.g., 100 iso FF and 400 iso 4/3.

 

However, this has absolutely NOTHING to do with actual measured EV for a certain ISO and f-stop and shutter speed used, and nothing with an "equivalent iso". If you'd say "equivalent noise levels", I'd agree, but only then.

 

IOW, what we knew already is even more true for 4/3: the lower the iso used, up to a point (base iso), the more total light will be received by the sensor, per area unit, and the lower the noise will be, but we do need to be careful to not overexpose, obviously.

 

Having said all that, it really is a moot point. Sensors, even 4/3 sensors, are way better than 35 mm film anyway in equivalent isos. This is mostly due to the fact that good amateurs got about 30 -40 lp/mm resolution from 35 mm film, and good pros about 60 lp/mm. We were already at this stage when we reached 6-8 MP and 12 MP respectively, and this is apart from everythign else we can do with digital as compared to film/analog.

 

In addition, what I also mentioned, if you do need thin DoF, and/or higher light intensity, use a Metabones adapter for your FF lenses, either a 0.71x Speed Booster, or a 0.64x one, which give you respectively a final crop factor of 1.4x and 1.28x (APS-H), and an f-stop increase of 1 stop and 1 1/3 stop. This also relates to the increase in teh amount of light reaching the sensor, and therefore the option to lower iso by 1 stop or 1 1/3 of a stop, and hence lowering noise levels (up to base iso).

 

Finally, what is really the point? I used to push 400 ASA/iso film to 1600 or 3200 in the past, resulting in a terrible amount of noise, even if we didn't call it that back then, and still printing good and acceptable photographs of 40 cm x 60 cm from it. But then, we didn't pixelpeep in those days, and we looked at pictures from appropriate distances (actually most "normal" people still do).

 

In the end, it is about the art, not about perfect pictures from a noise/DoF/FL POV - those are just means to get a result, to control the results we want to achieve, no more no less, and it serves no purpose to contnuously point out how bad everything is while we could do it the other way around.

 

A 20 cm x 30 cm print from a 4/3 sensor when captured and processed well, is better than anything we could do before the advance of digital, from a technical POV, and for me and many others that is more than good enough, considering the parameters, one of which is most definitely weight and size.

 

Regards, Wim
Gear: Canon EOS R with 3 primes and 1 zoom, 4 EF-R adapters, Canon EOS 5 (analog), 9 Canon EF primes, a lone Canon EF zoom, 2 extenders, 2 converters, tubes; Olympus OM-D 1 Mk II & Pen F with 12 primes, 6 zooms, and 3 Metabones EF-MFT adapters ....
#40
I'm with Wim here.

 

ISO 100 on MFT is equivalent to ISO 400 on FF as far as the quality of the end result is concerned (for the same amount of pixels).

A FF camera has a 2 f-stop speed advantage over MFT - this is a baseline and it has to be taken into the equation when talking about speed equivalence. The characteristics of the end result are the only things that count in this discussion - thus field-of-view, depth-of-field and image noise.

 

Of course, a 10mm f/2.8 (MFT) has the same speed as a 20mm f/2.8 (FF) when you just look at the lens. However, a naked lens is merely good for a paperweight without a camera behind it. We are always talking about SYSTEM equivalence here.

  


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