Do you confirm...

[Annibale G.]

do you confirm the best stop for leica M 35 f/2 is 5,6 ? while for the M lenses 50 f/2 are 2 and 2,8?
Thanks
Annibale

[arminw]

Well, I guess that entirely depends on what you are shooting and the condition you find yourself in . In general I can say that all stops I have used on the 35 and my 50 are fantastic and the results are more then satisfying .

[lambroving]

Are you speaking of the 35/2 ASPH? If so, it is sweet between f2.8 - f5.6. Probably best overall at f4. By f8 it starts to degrade slightly in contrast. Older lenses improve at f5.6. Newer lenses are designed to shoot superbly wide open. This was at f2.8 at 1/30th if memory serves. Can't link to the post in the old Forum which was better as Andreas seems to have lost it! Early Morning Light

[luigi bertolotti]

ah...in my opinion it depends upon WHICH 35/2 You are dealing with : I have
35 1st type Wetzlar : better 5,6 than 11
35 3rd type (CAN) : better 11 than 5,6

[stunsworth]

Most Leica lenses that I've used have been best in the f4-f5.6 range.

To be honest they exceptional compared to most of the opposition at all apertures :-)

[erl]

Originally Posted by Annibale G.

do you confirm the best stop for leica M 35 f/2 is 5,6 ? while for the M lenses 50 f/2 are 2 and 2,8?
Thanks
Annibale

Ah! you fail to state "best for what purpose". Given different tasks, all lenses will be 'best' at different apertures. Landscapes (although not mine) would be best stopped down. Portraits of a particular character would be best wide open to separate background. Already I hear the dissenting voices who like to work another way. There is no overall 'best'. Only best for a spefic purpose.

Cheers,
Erl

[earleygallery]

There's no 'best' 'right' or 'wrong'

Use the aperture you want for appropriate depth of field or shutter speed. Its the image wot matters!

[andybarton]

James.

There speaks the voice of reason...

I really can't get to grips with this "Leica lenses are best at sub f4 apertures" mentality.

If you want a deep d.o.f., are you expected to get out your Nikon lenses? I don't think so...

Use whatever aperture you want for the photograph you want to make. If it's greater than f4, your Leica lens will be as good as the best alternative available. You don't have to shoot wide open, just because you use a Leica.

What more do you want?

[lambroving]

Originally Posted by earleygallery

There's no 'best' 'right' or 'wrong'

Use the aperture you want for appropriate depth of field or shutter speed. Its the image wot matters!

Brother James,

Correct me if I'm wrong, but neither you nor certainly Andy has much experience of M lenses. Naturally, if you are stuck, and 1/1,000th isn't enough..., but if you are into image quality, you use the strengths of the lenses where they perform best. Late M lenses are designed to perform best when stopped down one or two stops. Older designs like my 21/3.4 SA are just O.K. at f5.6 but really shine at f8 - f11.

If you are curious, read Puts's old M lens book or I'll mail you the pdf if it's not on the Internet anymore.

[earleygallery]

Hi William,

I know all lenses will have their particular 'sweet spot' but I stand by what I said - I select the aperture I want with DOF in mind usually. I'm only ever controlled by extremes of lighting conditions, i.e. needing to shoot wide open for the fastest shutter speed or stopped down due to brightness. I would never think of using a lens only within a given stop or two.

I doubt anyone looking at the resulting images will ever think 'if only he'd shot that at f5.6 instead of f4....'

Anyway, were shooting Leica here - the lenses should perform acceptably at all apertures.

[lambroving]

James,

The ASPH lenses are best wide open to f5.6. At f8 they start too look like your R lenses. Contrast really drops. At f11 defraction really sets in. It isn't hard to see. Trust me. Acceptable isn't O.K. when you can open up and get outstanding. Outstanding is what the $$$ is for.

[ddp]

I rarely shoot beyond f8. Like William said, these lenses are made to perform from wide open on, and that's how I tend to use them. I know I can shoot wide open, or one or two stops down and get the look I need.

[rob_x2004]

You guys use ND filters much? The other day I was at thousandth 8,11,16 till dusk on 100ISO. Happens quite a bit over summer here.

[ddp]

I have toyed with the idea of using ND filters, but have yet to bite the bullet.

[lars_bergquist]

'Best' f-stop is always a matter of your intentions -- plus a good deal of subjectivity. Let's define our terms:

'Sharpness' is just your personal impression. It's not quantifiable. 'Definition' is, as a measure of the contrast in the rendering of edges and detail. This is of course the MTF, and the curves for 10 and 20 line pairs per millimeter (lpm) are the most important.

Second, which definition? Maximum definition at the plane of best focus, and in that case, on the optical axis only, or with the corners weighed in? In the first case, it's a good rule of thumb that whilst the general run of older lenses (a couple of lemons excepted) perform best at about three stops down from wide open, fast lenses did usually want four. The current 'super lenses', aspherical and apochromatic and all that, need only two or less; also, they are far better wide open than the old lenses were at those f-stops.

On the other hand, it is also legitimate to consider the image in its entirety, which brings in not only the corners, but also the matter of depth of field (d.o.f.). That is, stopping down more than indicated in the paragraph above may make the entire scene look 'sharper'.

Now, as you stop down more and more, the garden variety optical aberrations like chromatism or coma continue to decrease, but another phenomenon rears its fuzzy head: diffraction. Now, if no other lens problems existed, then an f:1 lens would be sharper than an f:2 one, and the f:1 optic would be at its sharpest wide open! Now, the better corrected the ordinary aberrations are, the quicker do we reach the point where these decrease less than diffraction increases (i.e. where the lens is 'diffraction limited'). So, though we should always avoid the really small stops if we want to maximixe definition in the plane of best focus, we should actually avoid them more with the super lenses! Now, increasing d.o.f. may of course still increase the general impression of sharpness, even though the image is still ever so slightly degraded in the plane of best focus. You must decide for yourself what you're after.

In sum: There's no substitute for knowledge, and for judgment in its use. Rules of thumb, like those in the beginning of this epistle, are just that, and no more.

May the Force be with you. The old man from th Age of Intelligent Photography

[bobtodrick]

Good answer Lars. In my opinion anyone who is this concerned about sharpness/f-stop should probably be looking at a format other than 35mm.

[stunsworth]

Well it seems that while the lenses may be at their technical best at f4-5.6 (which is what I assumed Annibale was asking, there are overriding _artistic_ reasons why you would want to use an aperture outside of that range, James' reference to controlling DOF being the major one. Unless of course you only shoot test charts, in which case f4 is just dandy ;-)

The question to be asked is do you take photographs to show how sharp the lenses are, or do you take photographs becasue you like photographs.

[KM-25]

Hmmm...good thread.

While I can confirm that my 28 and 50 aspherics are stunning wide open, they do not disappoint at 5.6 and slower either. I think that beyond actual sharpness, contrast is the other thing to weigh in.

For example, for the next 3-5 years, I am shooting only Kocachrome in my film bodies.
So the film sets the limit I have to work around. For most low to normal contrast scenes, the Lieca optics are my choice. But when the scene is bonkers in contrast, I will use some of my Nikon AIS glass on an FM3 to employ a lower contrast lens. I also like using my Hasselblad XPan in higher contrast scenes as the lenses are even lower contrast than some of the Nikons.

The way the film responds to light is something I can not control without altering the light in the scene. So like a printer uses contrast filters for printing black and white, I use lenses to control the same contrast.

[stunsworth]

One other thing in response to William's reply above, diffraction is related to the physical size of the aperture not the f-stop, so the longer the lens the higher the f-stop can be used before diffraction becomes an issue. F11 on a 90mm isn't the same as f11 on a 21mm from a diffraction point of view.

[dfbldwn]

Originally Posted by stunsworth

diffraction is related to the physical size of the aperture not the f-stop, so the longer the lens the higher the f-stop can be used before diffraction becomes an issue. F11 on a 90mm isn't the same as f11 on a 21mm from a diffraction point of view.

Here, Here!

Thank you Steve