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M8 135mm question

jrc

By jrc
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jrc

jrc

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Leica says the 135mm won't work with the M8. Does this mean that *physically* it won't work for some reason, or does it mean that there are problems focusing? Is it possible, if you're planning to use the 135 as a 179.55mm, but only to take pictures of things that are relatively far away, that you can just turn it to infinity focus and use it that way, in focus? Or for some reason does this not work?

 

JC

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cbretteville

cbretteville

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Andy Piper posted a note about testing a 135 Tele-Elmar on the M8 a little while ago and loving what he could see from the image on the M's screen.

 

AFAIK the goggled 135 has a bar code, all other 135s are considdered not suitable by Leica. If you can work out how to use it there is no reason why you shouldn't.

 

- Carl

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wparsonsgisnet

wparsonsgisnet

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Using a 135mm lens without the goggles should be ok if you close down to 5.6 or so, right? Then your focus error can be accomodated for by the extra DOF. And, the longer lens will give you back a narrower DOF.

 

Circle me confused.

 

Gimme the camera!

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ho_co

ho_co

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All the 135's will physically fit and function fine on the M8. The problem is simply one of focusing accuracy.

 

According to LFI a couple years back, the M series with 0.72x magnification has barely adequate focusing accuracy for the current f/3.4 135. The article also pointed out that its calculations were based on the traditional but now out-of-date standard circle of confusion.

 

In other words, TECHNICALLY the current film Leicas cannot focus the 135/3.4 accurately wide open without extra magnification--either the 0.85 finder or the 1.25x magnifier.

 

The M8 has less magnification and for comparable performance requires a yet smaller circle of confusion because of the smaller sensor. Thus the M8 is even less suitable to best results with the 135's other than the f/2.8.

 

Leica fudges the issue a bit by saying only that the 135 frame on the 0.72x film cameras is too small to work with comfortably--and that is certainly the case.

 

The 135/2.8 keys the 90mm frame line and provides 1.5x magnification, more than even the 1.25x magnifier. Therefore the 135/2.8 is completely and unrestrictedly usable on the M8.

 

NOTE: The fact that something "doesn't work" technically doesn't mean it won't work for you. You may have better eyesight than usual, or better concentration, or just better luck. Go ahead and use the slower 135's; stopped down they will be just fine, but the explanation above is the reason the 0.58x film cameras and the M8 do not have the 135 frame: Inadequate focusing accuracy wide open.

 

--HC

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edlaurpic

edlaurpic

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I use my 135 f/3.4 on my R-d1s with a 1.3x magnifier made by MS Optical in Japan, and it works fine for me. I expect that it will work on the M8 pretty well with the !.25x magnifier. As far as framing, just use the rangefinder center patch and estimate double the width and height of it and it works pretty well. I also chimp and reframe if the shot doesn't work.

 

The 135 3.4 is a terrific lens, much better in almost almost every way than the old 135 2.8, IMHO. Also, the 138 2.8 is huge compared to any other M lens.

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ho_co

ho_co

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I use my 135 f/3.4 on my R-d1s.... As far as framing, just use the rangefinder center patch and estimate double the width and height of it and it works pretty well. I also chimp and reframe if the shot doesn't work.

I think that will likely work fine on the M8 as well, Ed, and as you say, with digital you can correct an error immediately.

 

The 135 3.4 is a terrific lens, much better in almost almost every way than the old 135 2.8, IMHO. Also, the 138 2.8 is huge compared to any other M lens.

The 135/2.8 grows bigger and heavier the older you get, too! ;)

 

There were a couple versions of the 135/2.8. The later one was quite good. But then Leica solved the problem of "Which 135 for me?" by eliminating both and replacing them with the current APO. And you're right, it's superb!

 

--HC

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zapp

zapp

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All the 135's will physically fit and function fine on the M8. The problem is simply one of focusing accuracy.

 

Leica fudges the issue a bit by saying only that the 135 frame on the 0.72x film cameras is too small to work with comfortably--and that is certainly the case.

 

NOTE: The fact that something "doesn't work" technically doesn't mean it won't work for you. You may have better eyesight than usual, or better concentration, or just better luck. Go ahead and use the slower 135's; stopped down they will be just fine, but the explanation above is the reason the 0.58x film cameras and the M8 do not have the 135 frame: Inadequate focusing accuracy wide open.

 

--HC

 

The frame lines in the viewfinder would be really small - that is indeed a if not the problem. The whole discussion about focus accuracy is misleading in my opinion. Do the same calculation for the Noctilux and you will see that if you cannot focus a 3.4/135 correctly you may ask yourself how to correctly focus the Noctilux of the Summilux 75 wide open?

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lct

lct

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....Do the same calculation for the Noctilux and you will see that if you cannot focus a 3.4/135 correctly you may ask yourself how to correctly focus the Noctilux of the Summilux 75 wide open?

According to my usual formula, there is no problem for the Noctilux but at full aperture, the 75/1.4 and 90/2 lenses are out of the accuracy range of the M8 if one don't use the 1.25x magnifier.

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ho_co

ho_co

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Do the same calculation for the Noctilux and you will see that if you cannot focus a 3.4/135 correctly you may ask yourself how to correctly focus the Noctilux of the Summilux 75 wide open?

The thread concerns the 135 lenses, so I didn't mention the others. As I said above, working with the small 135 frame is indeed a pain at all apertures.

 

The graph I mentioned (LFI 8/2004, p 35) shows that the 50/1.0 will work fine with a finder magnification of 0.58x, and both the 75/1.4 and 90/2 will just barely work with the same 0.58x magnification. Working with a reduced circle of confusion but an increase of magnification to 0.68x keeps those two approximately the same, with additional magnification strongly recommend for both longer lenses.

 

The graph also shows that a finder magnification of 0.72x is just barely inadequate for accurate focus of a 135mm at f/3.4, but fine for the same focal length at f/4. (The 0.85x finder fully covers all these cases, of course.)

 

But note that the calculations in LFI are based on a circle of confusion of 0.030 mm; the magazine states that this traditional figure is today outdated and should be 0.020 mm. With its 4/3 crop factor, the M8 would require an even smaller circle of confusion, more like 0.015 mm if my understanding is correct.

 

On this forum before the M8 was introduced there was a lot of discussion of its focusing accuracy, where LCT compared focusing accuracies of a number of finder magnifications--something you might be interested in.

 

Check the graph, or go with LCT's computations. Unfortunately, they both say you've miscalculated somewhere along the line... :(

 

But the bottom line is: Use the 1.25x magnifier with long and fast lenses.

 

--HC

___

 

Der Ball ist rund. Das Spiel dauert neunzig Minuten. Alles andere ist Theorie!

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ho_co

ho_co

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One more quick & easy check on RF accuracy with all lenses 50mm and longer:

 

http://www.imx.nl/photosite/leica/technics/rfaccuracy.html

 

The physical baselength of the rangefinder of all M cameras is 69.25 mm. Multiply that by the M8 finder magnification 0.68 and you get an effective measuring baselength of 47.09 mm.

 

Puts's chart "Based on point distance discrimination" shows that:

for a 135/4.0, minimum effective baselength needed is 45.6 mm; and

for a 135/3.4, minimum effective baselength needed is 53.6 mm.

 

Remember that with the smaller allowable circle of confusion dictated by the smaller frame of the M8, these minimum baselengths would be increased.

 

--HC

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ho_co

ho_co

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Leica Camera AG, are you listening in? So bring us either a .85 X finder version, or a 135/3.4 with goggles keying in the 90 mm frame -- or why not both!

Lars--

I won't argue with your preference, but Leica probably feels they've already answered. Using the 1.25x magnifier on the M8 gives you exactly the 0.85x you want, and removing it still keeps the wideangle frames available. Remember, the M was always a wideangle camera.

 

The goggles are an excellent idea, but add bulk and weight. And they are relatively easy to bump out of alignment.

 

Remember, when the M3 came out it was a triumph. But people didn't like the goggles on the 35mm (among other things), so the M2 came out with lower magnification >>because a lot of people asked for it.<<

 

In the M8 we've got the birth of a new family, and there are sure to be later improvements.

 

But I dare you to wait for the M9 before buying! :cool:

 

--HC

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jrc

jrc

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You know what would have been neat? A sliding, click-in-place 1.25 magnifier built into the camera, that you could move back and forth depending on which lens you were using. Or, second best, a tiny bayonet-mount magnifier that you wouldn't have to fumble around for two minutes to get screwed in.

 

JC

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