Some M8 advantages

[Gerard]

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There are a few of those in and around Somerset!

 

Ain't that the truth.

[pgk]

The CofC should be determined by the output requirement.

 

The problem we have is that comparisons of 'identical' output images from two differently sized sensors are not the same as an image from a sensor and the same image cropped. Think about it.

[lct]

DoF depends on CoC, focal length and aperture. Hence hyperfocal formulas like H = f^2/Nc+f where f is the focal length, N the aperture number and c the circle of confusion. Or H = L2 / (f * CoC) where L is the focal length, f the aperture number and CoC the circle of confusion

 

CoC depends on the diagonal of the format so whatever CoC value one chooses for FF, the M8 CoC will always be 1.33x smaller. For a FF CoC value of 0.030mm, for instance, the M8 CoC will be 0.030 : 1.33 (or 0.030 x 32.45 : 43.27) = roughly 0.023 mm.

 

Those interested might wish to take a look at those DoF & CoC calculators:

Online Depth of Field Calculator

Circles of Confusion for Digital Cameras

[Guest EarlBurrellPhoto]

As thrilling and exciting as it is to delve into physics and theory and scour the internet looking for laboratory tests that support it (), if anybody has any interest at all in actually taking pictures, they will note that if they frame identical compositions at the same aperture with an M8 and a full-frame camera, the M8 shot will exhibit more apparent DOF. However it will be barely equivalent to stopping-down the lens of the full-frame camera by one stop. Hardly noticeable except at close-focus distance, and given the limited close-focussing of the M camera, not glaring at that either. Again, results gleaned from actual picture taking.

[pgk]

But lct, the circle of confusion is entirely dependent on the final output size of the image and the viewing distance - which is why it is difficult to create substantial differential focus on small images viewed on, for example, a website. The values usually quoted in the formulae you linked to are theoretical and based on (I assume) 100% enlargement on computer screen or some other such concept - they do not appear to be defined. In the real world (ie looking at an image in a magazine or book or at a print rather than a computer screen at 100%), the circle of confusion may be somewhat different which is why I stated that it should be determined by output requirements - this is a practical actuality as opposed to a theoretical concept. As for the diagonal of the format, well again this is an old rule of thumb and whilst its valid, it again assumes a viewing distance equal to the diagonal I believe.

[Angelos Viskadourakis]

to make it more practical though totaly unrelated to this thread, DOF is mathematicaly calculated using CoC ,but but, sooooo........ many buts.

 

1/a soft lens with low contrast have apparently greater DOF compared to a sharper lens as DOF is a visual perception experience in practice,under the same lighting

the eye compares the sharp to unsharp parts of images and the human brain at split seconds declare something in focus or out of focus but mostly by comparison.

 

2/in dark background with backlighting the DOF appears smaller compared to an image shot in the dessert during a sand storm or in mist.

 

3/under soft diffused lighting the DOF appears larger than in a contrasty scene.

 

4/a flat background with no texture make the impression of greater DOF compared to a contrasty BG with darks and highligts-melting highlights eg,the sun through a dense folliage.

 

etc bla,bla,bla (this is not a thread related to DOF general discussion,right?????)

 

that is why earlier i said those they consider it a plus to find some more exciting plus to support a camera.

Also M9 and M8 have obviously thinner DOF compared to EPSON RD1 that some posters are using but between M8 & M9 someone has to work hard to find the diferences in DOF even though physicaly exist.

[lct]

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But lct, the circle of confusion is entirely dependent on the final output size of the image and the viewing distance...

Whatever value one chooses for FF CoC, the crop CoC will always be smaller. For instance, the M8 CoC will always be 1.33x smaller. There is no way one can escape that.

[lct]

... Hardly noticeable except at close-focus distance, and given the limited close-focussing of the M camera, not glaring at that either. Again, results gleaned from actual picture taking.

I'm taking actual pictures with FF and crop cams as well so i'm a bit surprised that you don't see the obvious difference yourself. Let's take a simple example. If we use a 28/2.8 lens at f/2.8 on our FF camera and want to take the same pic with an APS camera, we need a 21/2 lens. Problem is there are not many lenses like that on the market.

[pgk]

Whatever value one chooses for FF CoC, the crop CoC will always be smaller. For instance, the M8 CoC will always be 1.33x smaller. There is no way one can escape that.

Of course there is. Try this way of looking at it - say a print from a shot with an M9 is cut down (cropped) to equate to a 1.33x factor. What is the difference between this print and the original print in terms of depth of field? Nothing if viewed at the same distance (because obviously its just a part of the same print). If you view from a different distance or actually enlarge this section to the original print dimensions then you have changed the magnification applied to it and consequently you need to use a different CofC. You've changed final output size and/or viewing distance - so CofC is affected.

[lct]

Hey my friend you're intoducing variables here. If you want to compare, you must do it in the exact same conditions.

[Guest EarlBurrellPhoto]

I'm taking actual pictures with FF and crop cams as well so i'm a bit surprised that you don't see the obvious difference yourself. Let's take a simple example. If we use a 28/2.8 lens at f/2.8 on our FF camera and want to take the same pic with an APS camera, we need a 21/2 lens. Problem is there are not many lenses like that on the market.

 

If you are taking actual pictures with FF and an M8, I'm a bit surprised you don't see there is only a very slight difference in DOF between the 28 @ 2.8 and a 21 @ 2.8 except at the very closest distance the lenses can be focussed on the M cameras (.7 metres). If you consistently shoot those ultrawide lenses at subjects at or under a metre, then I would allow that you have a very specific need for FF. Everyone else, not so much.

[lct]

If you are taking actual pictures with FF and an M8, I'm a bit surprised you don't see there is only a very slight difference in DOF between the 28 @ 2.8 and a 21 @ 2.8....

There is twice more DoF at 5 meters with the 21. Hardly 'very slight' in my book:

 

 

[plasticman]

There is twice more DoF at 5 meters with the 21. Hardly 'very slight' in my book

 

LCT - I often agree with you, but in this comparison between the M8 and M9, the infinity of other variables that determine the apparent DOF of a real image make the differences between the cameras insignificant.

[Guest EarlBurrellPhoto]

+1. In real photography I can't think of what sort of subject I would fit a 28mm FOV, focus on a subject plane @ 5m, and not want more DOF rather than less. In that example the added DOF of the M8 and 21mm would, in real, practical, typical photography, be an advantage. I thought you were talking about shooting in-your-face photojournalist-style, perhaps @ 1-1.5m, trying to minimise the DOF of the ultra-wide to make the subject pop.

[lct]

Sounds like we must agree to differ gentlemen. Thanks to have heard me anyway.

[SJP]

zzzzzzzzzzz, return of the living dead. I fully agree with lct.

 

We really need a sticky on DoF and such to eliminate this recurring discussion.

 

Excutive summary:

DoF depends on sensor size because of the way DoF is defined (it includes viewing the print or screen at a standard viewing distance equal to the print/screen diagonal, and some assumption on how sensitive the human eye is to blur in the image) - this is not a matter of opinion it is just how it is set historically, just like the kg, metre, inch, leapyear etc. Don't believe me just ask the pope.

 

The consequence of this is that the same lens on the RD1, M8, M9 (etc.) will have a different DoF due to the different sensor size. Despite the fact that the lens images exactly the same on the plane of the sensor.

 

You are free to deviate from the standard definition depending on whether you always make 4x6 cm snaps and look at them without wearing your spectacles or always do A0 prints & use a magnifier. But this is a personal choice and does not change the standard definition.

C'est tout.

 

Having said some like the M's for "bokeh" and the M9 has an advantage there, others want a large DoF and then the Rd1 is the best tool. That is purely a matter of opinion. For me I prefer the isolation that a small DoF can produce. For big DoF then I could live with a Point & Shoot (except for the lens distortions & such).

[Gerard]

Having re-read through the last nine pages, I'm with Nicole on this one; the main benefit of the M8 is, to me at least, is actually having one. I'm relatively new to photography, and am trying to learn, fast. This thread has lost me, though; it's a discussion at a level of science way beyond anything that will help improve the images I produce right now. So, it's been good; but not sure I've learnt much... and I'm off to the photo forum.

[Angelos Viskadourakis]

Having re-read through the last nine pages, I'm with Nicole on this one; the main benefit of the M8 is, to me at least, is actually having one. I'm relatively new to photography, and am trying to learn, fast. This thread has lost me, though; it's a discussion at a level of science way beyond anything that will help improve the images I produce right now. So, it's been good; but not sure I've learnt much... and I'm off to the photo forum.

 

i understand it looks like a habbit-for some- to distract a thread with uninteresting info and irrelevant

issues-obviously a technique not so exciting and i agree realy boring.

 

 

http://www.l-camera-forum.com/leica-forum/digital-forum/103910-voigtlander-lenses-w-m8-m9.html

 

see post 12 for some DOF with M8 and CV ULTRON 28 at f 2.8 check the crop ,from a wide shot with M8 there are barely 6 cm of DOF ,from the tip of the nose just barely to the eye,and that is a crop from the much wider shot,i realy cannot have thinner DOF.

[SJP]

M8 & M9 have one but not real that of a difference in DOF,M8 is very close to M9 regarding DOF and M8 has already small and critical DOF,for EPSON rd1 i will not comment people already know about it and i dont see a reason to be included in the discussion,but if you like it so much ok.

I don't have a Rd1 and therefore I don't like it. The difference in DoF between the M8 and the M9 is about 1 stop if we ignore all the subtleties in the real calculations. So if you want the DoF and effective focal length of a Noctilux on an M8 you need to buy a 35 mm f/0.7, or if you mount a Noctilux on the M8 you end up with a 70ish mm f/1.4 in terms of the DoF (not the light gathering ability which remains invariant of crop etc.). Both comparisons show that you are getting a different camera for your hard earned money. Whether this is good or bad is not something I have any strong opinions on.

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Hallo,

Look here: Leica M

[Gerard]

see post 12 for some DOF with M8 and CV ULTRON 28 at f 2.8 check the crop ,from a wide shot with M8 there are barely 6 cm of DOF ,from the tip of the nose just barely to the eye,and that is a crop from the much wider shot,i realy cannot have thinner DOF.

 

Thanks, Angelos, I'll take a look.