Change my 21/2.8 Biogon for a18/4 Distagon??

[ho_co]

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Wilson--

The suggestion to wait till reviews are in is a good one, of course--but according to S Reid and G Mancuso:

 

In general, the Leica filters are weaker than B+W's, but Leica specifically made their 60mm and 67mm filters stronger than their others because they found their weaker filters too weak on the super-wides. (I'm bothered by speaking of 'stronger' and 'weaker' with regard to cutting IR: Seems to me that's like saying, "Well, yes, that's a stop-sign; but this one over here _really_ means you need to stop.")

 

Thus, it MAY be that the standard B+W filter is about equal to the Leica 60's and 67's.

 

It's certainly worth a try--get a 58mm 486 and try it out!

 

Of course, we're speaking of the current firmware. In the next update, out of interest in ultimate image quality (or out of interest in ultimate filter sales ), Leica may re-write the book on filter applicability.

 

In other words, we can't predict the future; so we have the choice of waiting for clear vision or jumping in for the best current choice.

 

--HC

[dseelig]

Being That You Are Using A 18 To Be A 24 It Might Be That A Leica 55 Filter Will Work With A Step Down Filter. Who Knows David

[sean_reid]

I'm glad to be proven wrong, Sean ... but have you asked what has prevented them from making the Distagon 15 coupled as well?

 

Hi Simon,

 

No, but I'll ask.

 

Cheers,

 

Sean

[carstenw]

I'm glad to be proven wrong, Sean ... but have you asked what has prevented them from making the Distagon 15 coupled as well?

 

It would have been too large! hehehehe.

[sdai]

It would have been too large! hehehehe.

 

No, Carsten ... actually I also talked with someone at Zeiss and the only reason seems to be that they don't think its necessary unless you shoot wide open and focus within 1m, otherwise the DOF is big enough to hold everything in focus.

 

I knew I was wrong even before I admitted it.

[sean_reid]

No, Carsten ... actually I also talked with someone at Zeiss and the only reason seems to be that they don't think its necessary unless you shoot wide open and focus within 1m, otherwise the DOF is big enough to hold everything in focus.

 

I knew I was wrong even before I admitted it.

 

That myth about DOF and UW lenses is common place. The fact is, though, that if one really considers "close enough" to be OK for focus (and it often is) then the ultimate resolution that a non RF-coupled lens is capable of is somewhat academic. Lenses hit their peak resolution at the distance they're focused at, not ahead of or behind that distance.

 

The Zeiss 15, which I tested extensively, is capable of class-leading resolution on center but only (of course) at the exact distance it is focused at. As such, the WATE can show stronger resolution, in practice, than either the CV 15 or Zeiss 15 simply because the former can be focused precisely using the rangefinder.

 

This is a common-sense reality that often seems to be overlooked.

 

I use zone focusing extensively but, when doing so, I always expect acceptable, rather than exceptional, resolution at an intended subject distance.

 

Even with a 15, one could better make use of the Zeiss' technical abilities if it were RF-coupled. With film, "close enough" is often just fine. With the M8, we'll certainly see the slight misfocus at 100% though it may mean little to the ultimate success of the picture.

 

Bottom line...since neither the CV nor the Zeiss 15 is coupled, one might ask why spend the significant extra $$ for the latter unless he or she needs F/2.8. The Zeiss does show higher contrast and a different kind of drawing but its resolution capability is a bit like high horsepower in a car with a slipping clutch. The power is there, in a potential state, but it can't fully be applied to the wheels. That's an imperfect metaphor, I realize.

 

This is also the kind of thinking that is not promoted by MTF charts and the like. A manufacturer can provide various charts (that may strongly interest some photographers) but one can easily forget that whatever resolution the chart suggests: A) Is associated, to a greater or lesser degree, with the specific focus distance the testing was done at (ie: resolution at three feet may not be the same at twenty feet) and Only applies to a lens that is *precisely* in focus at the intended distance. The real world variations in focus that come from human error, estimation, slight body movement, etc. often bear more upon the final result than do small numerical differences in MTF etc.

 

Cheers,

 

Sean

[sdai]

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I fully agree on your comments, Sean ... I must admit that I wasn't closely following the Distagons but knowing the 18 ZM is RF coupled for merely 1100 US, now I'm interested.

[Philippe D.]

Zeiss tells me the ZM 18/4.0 is rangefinder coupled.

Yes, i confirm, it is rangefinder coupled.

Got mine just one hour ago.

The first shots looks great (but not publishable).

I'm going out to take pictures with this 18mm (24mm on M8).

[Etruscello]

Some time ago, I emailed Zeiss Customer Service and asked about the 18mm f4 ZM. Their response specified that this lens IS rangefinder coupled. Tom P.