90 2.5 Summarit vs. 90 2.8 Elmarit ?

[250swb]

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But it doesn't get bigger or smaller. The light is measured off the spot on the curtain which is always the same proportion of the 35mm imaging area, irrespective of the lens on the camera.

 

It stays the same size. Perhaps if you hadn't edited out what I said about the 135mm frame line being about the same size as the metering area (in the viewfinder) the context would have been clearer. After all this is only a 'what if' in trying to work out why somebody consistently blows highlights such that the lens is blamed, it can only be the metering.

 

Steve

[jaapv]

But it doesn't get bigger or smaller. The light is measured off the spot on the curtain which is always the same proportion of the 35mm imaging area, irrespective of the lens on the camera.

Agree, if you "crop" the viewfinder area by using a longer lens the actual image area projected onto the sensor/shutter curtain will alter as well. The percentage measured by the camera off the shuttercurtain will stay the same, which means the "measuring spot" in your viewfinder has shrunk proportionally.

If you want to use the camera meter as a spot exposure meter you must measure using a 35 or 28 lens and take the image with for instance a 90 mm lens.

So you should say for instance that the measuring area is approximately the same size as the 90 mm framelines when using a 50 mm lens, or something similar.

Edited February 19, 2015 by jaapv

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[wattsy]

It stays the same size. Perhaps if you hadn't edited out what I said about the 135mm frame line being about the same size as the metering area (in the viewfinder) the context would have been clearer.

 

Yes, but the 135 framelines are only "about the same size as the metering area (in the viewfinder)" if you have something like a 28 or 35 lens attached. If you are attach a tele lens, the metering area shrinks to a much smaller proportion of what you see through the viewfinder. I'm not arguing with your point that blowing the highlights with a 90 comes down to user error (and metering technique may be a factor in that error) but I don't agree with your explanation.

[honcho]

......

If you want to use the camera meter as a spot exposure meter you must measure using a 35 or 28 lens and take the image with for instance a 90 mm lens.......

 

 

Now I know why some people really need camera bags.

[CheshireCat]

If you want to use the camera meter as a spot exposure meter you must measure using a 35 or 28 lens and take the image with for instance a 90 mm lens.

 

It is actually the other way around.

If you want real spot metering with a 90mm lens, then you meter with a 400mm and take the picture with the 90mm.

 

Be sure to bring your 400mm f/2.8 lens for metering

[CheshireCat]

After all this is only a 'what if' in trying to work out why somebody consistently blows highlights such that the lens is blamed, it can only be the metering.

 

No, it can be the lens.

The metering system will average the spot area and expose to make it middle-grey (think B&W for a moment).

 

Now check the B&W scale in my post here:

http://www.l-camera-forum.com/leica-forum/leica-m-lenses/317424-elmarit-m-90-11807-vs-zeiss.html#post2614350

 

The metering system will expose for the gray I have marked in the picture as "calibration" for both lenses.

Now see how the calibration gray is identical and the shadows are almost identical for both lenses. But there is a big difference in the white level.

 

EDIT: I will need to double check the original images, as vignetting in the APO Sonnar may be affecting the results. Nonetheless, in general, the metering will expose a high contrast-lens and a low-contrast lens for the same middle gray, but the high-contrast lens will be more prone to blow highlights (and/or lose detail in shadows).

Edited February 19, 2015 by CheshireCat

[honcho]

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It is actually the other way around.....

 

Did you really have to tell him?

[batmobile]

This is very true, but while I cannot comment on the Zeiss 135mm f2 SLR, my 90mm f2.8 Elmarit-M is appreciably lower in contrast than all my ZM lenses. My Zeiss lenses are the highest contrast lenses I have, along with the 24mm Elmar and 28mm Elmarit-M asph.

 

In normal use, did you have real problems with the highlights of your 90 Elmarit-M? If so, what M lenses do you ordinarily use?

 

 

No, it can be the lens.

The metering system will average the spot area and expose to make it middle-grey (think B&W for a moment).

 

Now check the B&W scale in my post here:

http://www.l-camera-forum.com/leica-forum/leica-m-lenses/317424-elmarit-m-90-11807-vs-zeiss.html#post2614350

 

The metering system will expose for the gray I have marked in the picture as "calibration" for both lenses.

Now see how the calibration gray is identical and the shadows are almost identical for both lenses. But there is a big difference in the white level.

 

EDIT: I will need to double check the original images, as vignetting in the APO Sonnar may be affecting the results. Nonetheless, in general, the metering will expose a high contrast-lens and a low-contrast lens for the same middle gray, but the high-contrast lens will be more prone to blow highlights (and/or lose detail in shadows).

[pgk]

Nonetheless, in general, the metering will expose a high contrast-lens and a low-contrast lens for the same middle gray, but the high-contrast lens will be more prone to blow highlights (and/or lose detail in shadows).

Believe me, if you have such a substantial difference in the contrast of the two lenses that you are comparing, you have a very big problem indeed:eek:! Your theory is okish but in practice you really aren't going to see much difference in these two lenses, honest!!!

[honcho]

Only a fool would use a 90mm Elmarit-M f2.8 as a spot meter.

 

Especially if it consistently blows highlights.

 

<---------

[jaapv]

It is actually the other way around.

If you want real spot metering with a 90mm lens, then you meter with a 400mm and take the picture with the 90mm.

 

Be sure to bring your 400mm f/2.8 lens for metering

 

How true Warthog moment, sorry...

[CheshireCat]

my 90mm f2.8 Elmarit-M is appreciably lower in contrast than all my ZM lenses.

 

I only have a ZM 35/2, and haven't compared it to the Elmarit.

I compared the Elmarit with my ZE lenses, which are high contrast lenses.

Sometimes the Elmarit felt lower contrast, some other times the other way around.

I don't know if it is a matter of coating, internal reflections, or something else.

 

I wish I had it still here to re-test it against the ZE 100 MP.

 

In normal use, did you have real problems with the highlights of your 90 Elmarit-M? If so, what M lenses do you ordinarily use?

 

I had more problems than with the other lenses.

The 90/2.8 used to be in the bag with: SEM 21/3.4, 35/1.4 FLE, 50/1.

All high contrast lenses wide open, apart from the 50/1.

Edited February 20, 2015 by CheshireCat

[250swb]

No, it can be the lens.

 

 

But your definition of 'high contrast' only seems to take into consideration the highlights. If you (or the high contrast lens) are blowing the highlights you should by any normal definition of contrast also be blocking the shadows and complaining just as much about that? If a lens is high contrast and you make a mid tone reading it will equally blow and block, but if it only blows (or only blocks) it's not contrast you are talking about at all but where in the comfort zone of the lens you place the exposure.

 

Steve

[pgk]

From an earlier thread:

Exactly. A 'contrasty' lens will differentiate tonality better, especially in the shadows. A low contrast lens will lose shadow differentiation due to veiling flare.

A high contrast lens is capable of better separation of shadow tonality due to well formulated and applied coatings, baffling of extraneous light and appropriate light absorbency paint applied relevant areas of the interior of the lens; all of which leads to a greater control of veiling and other flare. It has nothing to do with exposure!!! Veiling flare adds to the 'imaging light' so affects the shadow tonality regardless of the scene contrast, and whilst it also adds to all the 'imaging light' , in the 'highlight imaging light' it is of little consequence unless it is substantial (which shouldn't be a problem with any lens since the introduction of 'modern' lens coatings unless it is damaged). Simplistic but should make sense!

 

Whilst older Leica lenses can have problems associated with flare which reduces contrast (both shadow tonality and sometimes even general tonality) modern lenses such as the Elmarit-M are pretty good (mine is) and it isn't a problem unless the lens is shooting into the light.

 

If you are into testing gear then try shooting a controlled scene and then introduce flare by adding increasing amounts of light pointing into the lens. Adjusting exposure to maintain highlight positions (on the histogram) will only reveal shadow tonality loss.

[CheshireCat]

If a lens is high contrast and you make a mid tone reading it will equally blow and block

 

The sensor is linear, but is the lens linear ?

 

Note that we are talking about global contrast here (i.e. veiling glare) which may be affected by different causes internal or external to the lens (coating ? sensor reflections ? scattering ? sun rays angle ? ...) . I do not know if these causes are linear or not.

 

Any expert here ?

[Guest volker_m]

The sensor is linear, but is the lens linear ?

 

Yes, it is.

[pgk]

Note that we are talking about global contrast here

I fear that you are muddling up lens contrast and scene contrast. Lens contrast is the lens's ability to deliver the contrast of the scene onto the sensor - in practice always less than 100% due to some albeit small degree of flare. However the scene contrast can be way beyond the sensor's capability to record at either extreme. A high contrast lens will deliver more usable tonality than a low contrast lens, whether or not the scene is of high or low contrast. The lenses' contrast will not influence exposure to any great degree unless it is of really low contrast indeed. If you are getting an exposure difference between two lenses it is due to something else.

[menos I M6]

Wow - interesting discussion about metering and contrast concepts here ;-)

 

… just came back from a weeks trip - didn't bring a 90 Elmarit-M but decided to take the tiny 90/4 Macro along.

 

When it comes to contrast of all the 90mm lenses I have used on the M, the latest 90 f2.8 Elmarit-M certainly is among the high contrast lenses made by Leica in 90mm.

 

It is though (and that is important to me) NOT one of the latest, contemporary high contrast lenses as the 28/2.8 ASPH, 50/1.4 ASPH or 35/1.4 FLE, which I very much do not like mostly because of this very feature.

 

The Elmarit-M pairs wonderfully with a pre ASPH 50/1.4 or the often cited Mandler lenses.

 

 

Now when it comes down again back to the original topic of the thread, it really is a question of how much lens for how little money one can get.

- you get substantially more perceived build quality with the Elmarit-M at paying generally less money

- you get a half stop faster aperture with the Summarit for usually paying more

- you get a very useful slide out lens hood (as in cannot leave it at home as for it's inconvenience) with the Elmarit-M

- you get a full metal built with the Elmarit-M, should you be averse against the rubber used on the Summarit lenses

- the Summarit is available new with a full warranty (but paying substantially more than for a sound second hand Elmarit-M)

 

The Elmarit-M is a very modern looking lens. It is exceptionally good performing and can easily fit into a very modern lens kit.

When it comes to one lens vs. the other it really only comes down to the small spec differences above.

[pgk]

It is though (and that is important to me) NOT one of the latest, contemporary high contrast lenses as the 28/2.8 ASPH, 50/1.4 ASPH or 35/1.4 FLE, which I very much do not like mostly because of this very feature.

 

The Elmarit-M pairs wonderfully with a pre ASPH 50/1.4 or the often cited Mandler lenses.

I would agree that the Mandler era designs - of which the 90mm Elmarit-M is one - do show a commonality but I'm not so convinced its actually the 'overall' lens contrast. I've really tried to figure out just what the visual difference is between non-aspheric 'Mandler' era lenses and the latest aspheric designs. I've looked at the MTF data which shows little to help. And I've examined my image files as carefully as I can

 

My current conclusion/theory is that there is a smoothness of tonality in the images produced by the pre-aspheric designs which gives the impression of lower contrast. I wonder if this is to do with the 'bokeh' (at any aperture) or how the non-aspheric images are formed - at full aperture the effect is more pronounced, but in the Mandler designs not so visibly pronounced as aberrations degrade the image wide open. Conversely the later, aspheric designs show a 'harsher' tonality which may easily be mistaken for increased contrast.

 

Just my thoughts. And FWIW the Mandler era lenses used at mide or even small apertures can give a smooth, rich tonality which whilst only a nuance different from aspherics, does to me exist and can be very effective in large prints (of the right subject and given appropriate lighting, of course.

 

The question within this thread should perhaps be as to whether the non-aspheric current Summarits carry forward this tonality of Mandler's era today. I have limited experience of the Summarits but am not sure from what I have taken.

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Hallo,

Look here: Leica M

[batmobile]

One imagines that coatings and flare control measures have steadily increased too, so the change to more recent aspherical designs probably also brought other contrast boosting changes.

 

To my eyes, there is a clear difference in contrast between current asphs (most models) and many mandler era lenses. Just shoot a roll of film with both, develop and note the difference in the negs. It is often not subtle and probably much easier to see here than with digital. Its enought to affect speed rating and development.

 

The 35mm Summarit-M is lower in contrast than my 28mm Elmarit asph and 24mm Elmar, but higher in contrast than my older Summaron f2.8, which one would expect. The 35mm Summarit is also a little lower in contrast than my 35mm ZM biogon f2.