focus peaking on M240- Next to useless wide open?

[jaques]

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well... if that true- then either your Noctilux is a lot sharper than mine- or- My M240 example does not have as strong peaking. I just re-checked to be sure: zero peaking visible at f1- at 5 or 10 x.

[leicatraveller]

i m very disappointed about focus peaking of my M, its almost useless cause its almost invisible (and i have a good eyesight, 10/10 ))))

[leicatraveller]

sorry but is impossible to do street photography or reportage if you need magnify 10x and spend 10 seconds before to decide if its in focus

 

and anyway landscape is not in leica DNA, Bresson teach well what is the main use of a Leica

[quadraticadder]

I have found it works very well with the 75 lux and f1 Noctilux. While subtle, it is excellent and provides a much more accurate focus than the rangefinder which has some variabiltiy. If ONLY Leica would make an integrated EVF and combine with or eliminate the rangefinder for those that want this.

 

Works well with a 35 summicron at f 2.0 under standard room lighting. Especially with the EVF at 10 X. I don't have a lens thats faster....yet. It does need contrast. Looking at the cat picture (so many cat pictures in photo forums!!....I don't even like cats), I would focus at the black/white interface around the spoiled little brat's nose or eyes.

 

Best,

Steve

[jaapv]

sorry but is impossible to do street photography or reportage if you need magnify 10x and spend 10 seconds before to decide if its in focus

 

and anyway landscape is not in leica DNA, Bresson teach well what is the main use of a Leica

:confused:Why would you focus a lens on LV or EVF in street photography? That is what the rangefinder is for - if you have time to focus at all.

Anyway, if you need ten seconds - Turning the lens focus ring will instantly activate magnification, halfpressing the shutter will cancel it. You can focus nearly as fast as with the RF.

[ehovv]

Have you tried with a tripod? I have a noct 0.95 and have the same difficulty but I assume it is because I cannot hold the camera still long enough for the processor to determine proper focus, I don't use a tripod with my M so I never really confirmed it. My solution is simple -- focus with rf and take 2-5 shots stepping back and forth. one or two will get in focus.

[farnz]

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:confused:Why would you focus a lens on LV or EVF in street photography? ...

I do that with my 80 Summilux-R quite often, Jaap. Of course there's little option for focussing fast, non rf coupled lenses wide open.

 

I don't remember needing anything like 10 seconds and I find I usually get a good hit rate wide open just by normal contrast focussing through the EVF. The red FP lines can be distracting sometimes.

 

Pete.

[Tonki-M]

sorry but is impossible to do street photography or reportage if you need magnify 10x and spend 10 seconds before to decide if its in focus

 

and anyway landscape is not in leica DNA, Bresson teach well what is the main use of a Leica

 

say what? Leica is an excellent landscape camera, especially the new M. Just by using distance scale on your lens or using hyperfocal focusing, you can correctly focus without ever having to worry about misfocus. Leica lens is also ridiculously sharp with minimal distortion. M cameras also have excellent bulb mode where you only need to lightly press it to start and press again to stop...and it has time counter on the OVF. With the new M, live view guarantees critical framing, horizon level is also there. Want to use graduated ND filters? Lee's Seven5 is excellent adding only very slight vignette. The only con i can think of is the limited shutter limit.

[farnz]

... The only con i can think of is the limited shutter limit.

If you mean that lenses are typically diffraction limited beyond f/8 or f/11 then that's rather a significant limitation. Having spent 15 years or so as a dedicated landscape photographer using a Pentax 67 medium format camera and stopped down to at least f/16 and sometimes f/22 or f/32, the limit of f/8 or f/11 at a stretch prevents me from maintaining tack-sharpness from the close foreground to the horizon that I've been used to and is essential for certain pictures. That might not be a show-stopper for everyone but it is for me since I'm used to what I could achieve with other systems.

 

This is not to say that the M lenses are not suited to landscape photography but they are certainly limited by diffraction.

 

Pete.

[Tonki-M]

indeed i see your point. But no system is ever diffraction free. even the most popular system for landscape, the DSLR, are as prone to diffraction. As for stopping down for depth of field, perhaps 35mm format is at an advantage? You are after all shooting landscape from an optic of higher focal length, so less depth of field (compensated by small aperture). A 21mm at f8 is already sharp from 1m-infinity. For your Pentax to get the same DoF, you are shooting from a 45mm lens DoF, so of course you would need like an f22 or more to get similar DoF.

[farnz]

A fair point. I suspect that resolution and acuity come into play with the medium format equipment. I know that I can see much more clearly defined detail in my medium format prints at f/22 than I can with 35 mm at f/11.

 

But I think we've perhaps strayed a little off topic.

 

Pete.

[Tonki-M]

A fair point. I suspect that resolution and acuity come into play with the medium format equipment. I know that I can see much more clearly defined detail in my medium format prints at f/22 than I can with 35 mm at f/11.

 

But I think we've perhaps strayed a little off topic.

 

Pete.

 

agreed on both points

[01af]

... using a Pentax 67 medium-format camera and stopped down to at least f/16 and sometimes f/22 or f/32, the limit of f/8 or f/11 at a stretch prevents me from maintaining tack-sharpness from the close foreground to the horizon that I've been used to ...

No, it doesn't.

 

 

... the M lenses [...] are certainly limited by diffraction.

Modern M lenses are diffraction-limited from, say, f/2.8 or f/4 on—which is a good thing. It means they are pretty damn good. Lesser lenses are diffraction-limited from f/5.6 or f/8 on, poor lenses from f/11 or f/16.

 

But this must not be confused with their usage being diffraction-limited. In fact, when using equivalent focal lengths at or near infinity distance then all image formats will give you the same depth-of-field before any significant diffraction-related loss of resolution kicks in. For example, an aperture of f/9.5 on a 35-mm-format camera will give you about the same depth-of-field and the same degree of diffraction blur as f/22 on 6 × 7 cm format (assuming equivalent focal lengths). And at focus distances significantly closer than infinity, for any given amount of depth-of-field the smaller image formats actually will suffer less from diffraction than larger formats, not more.

 

Moreover, current-technology 35-mm-format digital with 18 or 24 MP has better resolution, wider dynamic range, and less noise than medium-format film. So modern high-end digital cameras are better landscape-shooting machines than the clunky Pentax 67 ever used to be.

 

 

I know that I can see much more clearly defined detail in my medium format prints at f/22 than I can with 35 mm at f/11.

35-mm film or 35-mm digital?

[farnz]

No, it doesn't. ...

<sigh> Yes, actually it does, 01af. Before you choose to contradict me again about what I can see plainly before me with my own eyes I'd be grateful if you did not please. Bear in mind that my Pentax saw lens focussed down to 300 mm so the foreground is particularly close. (And, yes, I'm familiar with hyperfocal focussing.)

 

35mm film; Fuji Velvia 50.

 

Pete.

[01af]

<sigh> Yes, actually it does, 01af.

No, it doesn't.

 

 

Before you choose to contradict me again about what I can see plainly before me with my own eyes I'd be grateful if you did not please.

You may see something clearly before your eyes but you don't necessarily understand what it means. You see more detail in the prints from medium-format film because this has more resolution than 35-mm-format film ... not because there was less diffraction.

 

If you'd compare prints from medium-format film against prints from 35-mm-format digital then you'd see what I'm talking about. At the same or better resolution, the smaller format is not, repeat NOT restricted through diffraction, compared to the larger format, when the focal lengths and the apertures are equivalent (i. e. same field-of-view and same depth-of-field).

 

By the way, I think I have to correct myself. In my previous post, I said the diffraction blur is the same for different formats at or near infinity but the smaller format suffers from diffraction less than the larger format at close-up distance. Meanwhile, I think if field-of-view and depth-of-field are the same then so is diffraction blur, regardless of focus distance.

[01af]

I just worked out a formula to compute equivalent focal lengths and apertures. It's a little more complex than most people think.

 

Consider 35-mm format and 6×7-cm format. Assuming the latter format's actual size as 56 × 72 mm, the diagonal is 91.2 mm which is 2.1× the 35-mm format's diagonal. Let's ignore the different aspect ratios for now. So the linear format factor q of the 6×7-cm format, in relation to the 35-mm format, is 2.1.

 

Common wisdom tells us that the equivalence factor eq is equal to the format factor q, or eq = q. So for a 50 mm lens at f/8 on 35-mm format, the equivalent focal length on 6×7 is 50 mm × 2.1 = 105 mm, and the equivalent aperture is f/(8 × 2.1) = f/16.8. However—this is accurate only at infinity focus, or magnification m = 0.

 

The accurate equivalence factor formula for format factor q and magnification m is this:

 

eq = (q + m) / (1 + m)

 

Note that for m = 0, the formula yields eq = q, and for m approaching infinity, eq approaches unity, regardless of q.

 

This means for a 50 mm lens on 35-mm format, focused for a magnification of 1:10 or 0.1× (approx. 1.2 m) at f/8, the equivalent focal length on 6×7-cm format is 100 mm (not 105 mm), and the equivalent aperture is f/16 straight. For a 50 mm lens on 35-mm format, focused for a magnification of 1:2 or 0.5× (approx. 0.23 m) at f/8, the equivalent focal length on 6×7-cm format is 87 mm, and the equivalent aperture is f/13.9. (NOTE: This is perfectly accurate only for "thin lenses" ... however real-world lenses aren't "thin" so there still is some leeway in these calculations.)

 

If equivalences are computed this way then depth-of-field will be the same for both formats, and diffraction blur will be the same, too. The maximum depth-of-field is attained when the diffraction blur disks are the same size as the maximum circles of confusion for the respective format—and for equivalent focal lengths, the maximum depths-of-field are the same for different formats. No advantage or disadvantage for the larger format in this regard.

 

Of course, given the same technology (either film, or digital with comparable pixel densities), the larger format simply has more resolution which is an advantage: it gives more detail, smoother tones, and richer colours. But this has nothing to do with diffraction limits—which will become obvious when comparing the larger format in old technology to the smaller format in new technology (so the smaller format catches up in terms of resolution).

[01af]

Uh oh. This is getting embarassing ...

 

In the formula above, there are two magnifications involved, and I confused them. Sorry.

 

So the 6×7-cm focal length equivalent to 50 mm focused at m = 0.5 (0.23 m) on 35-mm format is not 87 mm but 77 mm, and the corresponding 6×7-cm aperture equivalent to f/8 on 35-mm format is not f/13.9 but f/12.3.

 

So I shall re-formulate the formula(s) ... if anyone is still listening. Be f the focal length, k the aperture number, and m the magnification of the smaller format. Be q the smaller format's diagonal's length divided by the larger format's diagonal's length—so q < 1 always. Furthermore, be F the focal length, K the aperture number, and M the magnification of the larger format. Be Q the larger format's diagonal's length divided by the smaller format's diagonal's length—so Q > 1 always. Then the equivalencies are as follows:

 

q = 1/Q

Q = 1/q

 

Equivalent magnification:

m = M/Q = q*M

M = m/q = Q*m

 

Equivalent focal length:

f = F * (1 + M) / (Q + M) = F * (q + m) / (1 + m)

F = f * (1 + m) / (q + m) = f * (Q + M) / (1 + M)

 

Equivalent aperture number:

k = K * (1 + M) / (Q + M) = K * (q + m) / (1 + m)

K = k * (1 + m) / (q + m) = k * (Q + M) / (1 + M)

[jaques]

thanks for the equivalencies... but ah- how does that help with the focus peaking again? I got lost in abstraction somewhere.... ;-) No really- fascinating stuff- but:

 

seriously back to peaking- if the Sony a7 can be too loud- the Leica can be totally invisible wide open below f2. This renders it next to useless for ultra fast lenses wide open- Jaap- the RF is not always the best focus option- even for rf coupled lenses (like the f1 noct-w hich has a very shallow DOF at close range). And now that Leica have embraced live-view- and EVF- these are the capabilities I am questioning now- not the RF which remains superb- and mostly the best choice 95% of the time (plus the camera looks awful with the EVF on too- totally loses its ergonomics)

 

I still hope they can add an option- for the user- to adjust (increase) the strength of the peaking- a scale. surely even if it is limited by the hardware- the red visual signal could be increased?

 

Oh- one thing- Kai in the video I linked at the start- seemed to easily produce a series of in focus good shots using the focus peaking on the sony A7: only looking at the rear LCD without any magnification? I would prefer to have that and for it to be a little loud- than not at all-

 

but this seems to be largely impossible with Leica?

[01af]

... but ah—how does that help with the focus peaking again?

Not at all.

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[satijntje]

well... if that true- then either your Noctilux is a lot sharper than mine- or- My M240 example does not have as strong peaking. I just re-checked to be sure: zero peaking visible at f1- at 5 or 10 x.

 

I have the same experience as Jaques.

Wide open at 1.0 (I have the latest E60 1.0) and even going to 1.4 will not show appropriate focus peaking to assist you with getting the focus right.

I tried it last week, but light conditions were pretty poor. Will try soon with better light:cool:

 

 

John