M-ADAPTER L?

[rafikiphoto]

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I just noticed on a dealer's website under SL accessories the Leica M-adapter L for pre-order. There are scant details about this item there or anywhere I have looked. What advantages, if any, for the SL will this adapter have over the M-adapter T I have already?

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The Leica Q3 is available for pre-order at B&H Photo Video and Adorama

[jip]

None, they renamed the T Mount to L mount.

 

Also the leica T and SL are now booth called: Leica TL and SL.

 

So the Leica T mount has been renamed to L mount.

 

And the Leida T is now called TL.

 

So all the XL camera's wil use the L mount.

[pkwok]

I got one from our dealer locally. So far so good. However, the aperture reading in the SL EVF does not match exactly to that in the lens mechanically when I put a 50mm f0.95 on it, there is some minor discrepancy.

 

In the instruction manual, it is also quite odd, it mentions that many lens are not compatible, including the 50mm f0.95, the 35mm f 1.4FLE and many modern lens.

[John Black]

... However, the aperture reading in the SL EVF does not match exactly to that in the lens mechanically when I put a 50mm f0.95 on it, there is some minor discrepancy.

 

 

How would any camera know the aperture selected on a M lens?  There are no electrical or mechanical connections in a M lens to convey that information.

[250swb]

How would any camera know the aperture selected on a M lens?  There are no electrical or mechanical connections in a M lens to convey that information.

 

It makes an intelligent guess by cross referencing the ISO, the light meter reading, and the shutter speed. It is not always spot on, and if you are using say an ND filter that can throw the guess out by the same amount as the filter factor, but generally it is a reliable guide.

[pop]

It makes an intelligent guess by ....

Not quite: http://www.l-camera-forum.com/topic/216580-leica-m8-m82-m9-m9p-mm-mtyp240-faqs-questions-with-answers/page-3?p=2464098&do=findComment&comment=2464098

[geetee1972]

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but generally it is a reliable guide.

An exceptionally reliable guide is to look at the aperture ring on the lens

[Leicaiste]

 

 

In the instruction manual, it is also quite odd, it mentions that many lens are not compatible, including the 50mm f0.95, the 35mm f 1.4FLE and many modern lens.

 

 

Could you please post a picture of that page of the R-Adapter TL instruction manual ?

 

Thank you in advance.

 

Lucien

[pkwok]

I got one from our dealer locally. So far so good. However, the aperture reading in the SL EVF does not match exactly to that in the lens mechanically when I put a 50mm f0.95 on it, there is some minor discrepancy.

 

In the instruction manual, it is also quite odd, it mentions that many lens are not compatible, including the 50mm f0.95, the 35mm f 1.4FLE and many modern lens.

Sorry that I make a terrible mistake. The list of modern M lens is a list for compatible lens rather than incompatible. Sorry again for my misunderstanding!!    

[pkwok]

This is the page I read and made a wrong quote.

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

[250swb]

Not quite: http://www.l-camera-forum.com/topic/216580-leica-m8-m82-m9-m9p-mm-mtyp240-faqs-questions-with-answers/page-3?p=2464098&do=findComment&comment=2464098

 

I've read the bit you sent me to in the link and after many attempts at resolving its relevance have to consider you are just trolling. What do you mean by 'Not quite'?

[jip]

It uses a seperate eye and compares it with the TTL metering to calculate the aperture, so indeed a calculated guess.

[pop]

I've read the bit you sent me to in the link and after many attempts at resolving its relevance have to consider you are just trolling. What do you mean by 'Not quite'?

Sorry.

 

I linked to an entry in our FAQ which explains how the digital M cameras arrive at the aperture actually set on the lens because I thought you were interested in how the cameras do that. "Not quite" refers to how you seemed to suppose the camera was doing it.

 

I won't troll you again by trying to explain something.

[250swb]

Sorry.

 

I linked to an entry in our FAQ which explains how the digital M cameras arrive at the aperture actually set on the lens because I thought you were interested in how the cameras do that. "Not quite" refers to how you seemed to suppose the camera was doing it.

 

I won't troll you again by trying to explain something.

 

I was the one answering the question, I knew how it worked

[pop]

Again:

 

Query:

How would any camera know the aperture selected on a M lens?  There are no electrical or mechanical connections in a M lens to convey that information.

 

This answer is not correct:

It makes an intelligent guess by cross referencing the ISO, the light meter reading, and the shutter speed. It is not always spot on, and if you are using say an ND filter that can throw the guess out by the same amount as the filter factor, but generally it is a reliable guide.

 

Since the camera can not read out the aperture setting from the lens, it reckons the actual setting by the amount of light that is lost from passing through the lens.

 

The digital M has for this purpose in addition to the light meter within the camera an extra light meter in front of the body. It then compares the light measured with the extra light meter to the light measured through the lens. The ratio between the readings is - usually - a good approximation for the aperture selected on the lens. This is what it says in the FAQ entry I linked to above.

 

Note that neither the ISO setting nor the shutter speed have any influence at all on the reckoned opening. It's just the amount of light lost or not lost when passing through the lens.

 

Any other camera which reckons the lens aperture must do the same: it must reckon the amount of light lost in transit through the lens. No amount of "correlating" can retrieve that information from the ISO or aperture speed setting. You must know how much light there is outside of the camera and how much of that arrives within the camera.

[250swb]

.The digital M has for this purpose in addition to the light meter within the camera an extra light meter in front of the body. It then compares the light measured with the extra light meter to the light measured through the lens. The ratio between the readings is - usually - a good approximation for the aperture selected on the lens. This is what it says in the FAQ entry I linked to above.

 

 

 

But the meter reading from 'both' meters on the M has no relevance to determining the aperture unless the camera also factors in other variables. The meter reading for ambient light and the internal meter mean nothing on their own. It simply determines one is bigger than the other and the factor is 'x'. Without a datum point of ISO for example the factor of 'x' could be any aperture value. So you are trolling, as usual.

[pop]

But the meter reading from 'both' meters on the M has no relevance to determining the aperture unless the camera also factors in other variables. The meter reading for ambient light and the internal meter mean nothing on their own. It simply determines one is bigger than the other and the factor is 'x'. Without a datum point of ISO for example the factor of 'x' could be any aperture value. (...)

Not so.

 

The factor 'x' is fully and only dependant on the area of the aperture. Double the area and double the amount of light that will reach the sensor. The ISO setting merely adjusts the gain of the amplifier which process the signal that leaves the sensor. The ISO setting does not have any influence at all on the amount of light the lens lets pass. Neither has the shutter speed. The camera does not even have to know the widest aperture which the lens can produce. 

 

Again: The aperture determines how much light passes the lens. The ratio between the light passing through the lens and the light arriving at the body directly yields the aperture set at the lens. 

 

The ISO setting and the shutter speed determine whether you will fetch a dark or a bright picture, as does the aperture. The combination of those three values will determine the exposure. The ISO setting does not alter the diameter of the aperture in the lens. Neither will the shutter speed. Neither the ISO value nor the shutter speed is needed to determine the diameter of the aperture.

 

Presumably, you have a digital M camera. It's not frightfully difficult to test whether the calculated aperture value will change when you fiddle with the ISO or shutter speed setting while the lighting remains constant.

 

And please do mind your manners. It's no use calling other members trolls when you are clearly mistaken in the subject matter.

[Erik Gunst Lund]

Indeed ISO has nothing to do with this, it is an educated guess by the camera - From previous posting I made some years ago:

 

The principle was actually patented back in 2006 so accessible to every one
Although it wasn't a US patent until Oct. 15. 2009

DIAPHRAGM VALUE RECOGNITION US 2009/0256954

A method for determining the current camera aperture (working aperture) of lenses on digital cameras having a viewfinder eyepiece and internal exposure measurement through the lens is wherein a further external exposure measurement is carried out past the lens and the value of the working aperture is determined from a reference table stored in the digital camera from the difference Delta BV between the two measured exposure values BV(int) and BV(ext).


I have found it to be very accurate, much better than I initially thought possible:)          

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Hallo,

Look here: Leica L-Mount