21mm f3.4 vs 18mm f3.8

[chimray]

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Considering now to have a wide angle lens, try to search these 2 lens to see some comparsion, anyone can help ?

[marknorton]

The 21mm is a new lens and may not even be shipping yet, so I doubt you will find any meaningful comparison.

 

Caution is required with both the 18 and 24 Elmars and, I expect the new 21. The problem is that to make the lens compact and reduce costs, there is only a single helicoid which means the cam profile making contact with the focussing roller in the camera is steeply raked. That in turn introduces an interdependency between lens and camera which does not exist with the more expensive lenses where a second helicoid (and a third in some cases) is used and a flat or near flat surface presses against the roller.

 

Specifically, the rangefinder adjustment can change the lateral position where the roller makes contact with the focussing cam and affect the focussing accuracy. The theory of course is that the depth of field is such that this doesn't matter, however, there is one wrinkle.

 

Tim Ashley, who approaches these things in a systematic and rigorous way tried a number of 18mm's a year or so ago and could not find one which focussed accurately to infinity. Whatever the (in-)accuracy at close focus, the one adjustment you always want to be correct is the infinity stop because focussing beyond infinity causes severe problems. With a wide angle lens, it's often useful to be able to set the lens to infinity if the subject allows and let depth of field relieve you of the need to focus. That's fine, providing infinity really is infinity.

 

It may be that Tim Ashley's camera was at the limit of adjustment tolerances making this effect worse and both my 18 and 24 focus correctly at infinity. However, it is something to check carefully when you buy one of these lenses.

[chimray]

Thanks Marks, I know this new lens has already in stock now, but what is th purpose of Leica to issue this wide angle lens, already hav 18mm in 3.8 and this is 21mm 3.4, not a big difference ?

[efftee]

So other than the few stops advantage, a 21 Lux would produce much 'better' images? I'm really itching for a 21 (or 24).

[RoySmith]

Considering now to have a wide angle lens, try to search these 2 lens to see some comparsion, anyone can help ?

I cannot help with a comparison but I have the 24mm Elmar and love it. I used it recently in New Zealand.

Here are some samples:

Banks Penninsula

South Island

Mirror Lake

North Island Rainbow

 

Roy

[UliWer]

...

Caution is required with both the 18 and 24 Elmars and, I expect the new 21. The problem is that to make the lens compact and reduce costs, there is only a single helicoid which means the cam profile making contact with the focussing roller in the camera is steeply raked. That in turn introduces an interdependency between lens and camera which does not exist with the more expensive lenses where a second helicoid (and a third in some cases) is used and a flat or near flat surface presses against the roller.

 

Specifically, the rangefinder adjustment can change the lateral position where the roller makes contact with the focussing cam and affect the focussing accuracy. The theory of course is that the depth of field is such that this doesn't matter, however, there is one wrinkle.

...

 

That's interesting. I noticed with the M9 that the rangefinder is not fully aligned when the 3.8/18mm is at infinity position and I focus something far away. It alignes only when I go back a little bit from the infinity position which would indicate approx. 20 m on the lens - though the object is 200m or more away.

 

I notice this only with the M9; with M2, M6 and M8 the rangefinder is fully aligned in the infinity position for distant objects.

 

So it cannot be a "fault" of the lens but just one of the M9. I didn't bother about this yet , as I don't see any lack of sharpness with the lens.

 

Would it be recommendable to let the CS look after it, even when I don't have any problems with other lenses - even those which are sensitive for focussing problems?

[kipdent]

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I can say that after purchasing both the 21mm and 24mm Elmar lenses in an effort to decide which wide angle lens to keep for my M9, the results led me to the 21mm, and so I recently sold the 24. The 21mm field of view better matches my esthetic tastes in a wide angle, and I luckily have had no problems obtaining accurate focus at infinity. That the Elmar is an f/2.8 lens is also a bonus, in my opinion. So, I heartily recommend finding a used sample of this lens since, apparently, it has been (or will shortly be) discontinued in the face of the introduction of the f/3.4.

[LeicaPassion]

The new LFI compares the 21mm f3.4 with the f2.8.

[lct]

Just to avoid possible confusions, there is no Elmar 21 so far., The new 21/3.4 is a Super Elmar and 21/2.8 Leica lenses have always been named Elmarit. Earlier 21/3.4 and 21/4 were Super Angulon. This said, the new 21/3.4 is more compact than the Elmarits fortunately but it is still significantly bulkier than the tiny Skopar 21/4. It looks sharper than the latter at f/4 though.

[ho_co]

Chim, 21 mm is about as wide as I like to go. To me, it's a must-have focal length, but seldom sees use, since it's already in the "super-wide" category. (My "normal" is 28 mm.)

 

To me the 18mm seems quite a bit wider than 21mm, covering the same angle across the long side of the frame as the 21mm does across the diagonal.

 

But that's my feeling, and it may not agree with yours.

 

They are both among Leica's newest computations, and both excellent according to reviews I've seen, so field of view and size become the main deciding points IMHO.

[luigi bertolotti]

I've always considered 21 as the "right" strong WA on 24x36... but there is a consideration to think of, imho, and is INTERIORS : be it for architectural pics, or ambient, or people... I have often observed that something more can be useful (but never had a wider lens... my CV 15 is "M8 only"): just my 2c... but if you make often interiors, I think that 18 could be the best choice.

[giordano]

The 21mm is a new lens and may not even be shipping yet, so I doubt you will find any meaningful comparison.

 

Caution is required with both the 18 and 24 Elmars and, I expect the new 21. The problem is that to make the lens compact and reduce costs, there is only a single helicoid which means the cam profile making contact with the focussing roller in the camera is steeply raked. That in turn introduces an interdependency between lens and camera which does not exist with the more expensive lenses where a second helicoid (and a third in some cases) is used and a flat or near flat surface presses against the roller.

 

Specifically, the rangefinder adjustment can change the lateral position where the roller makes contact with the focussing cam and affect the focussing accuracy.

 

Wasn't precisely this the reason why long ago Leitz warned against using the Summicron-C and Elmar-C lenses on M bodies?

 

The fact that Leica are now selling M lenses with sloping cams must mean that either their standards are lower - which seems unlikely - or that recent bodies have less variation in the lateral position of the roller - in which case the Super-Elmars can be expected to be more problematic on old bodies than current ones. Or maybe Leitz just lied to us about about the C lenses.

[UliWer]

... - or that recent bodies have less variation in the lateral position of the roller - in which case the Super-Elmars can be expected to be more problematic on old bodies than current ones. ...

 

My experience with the 18mm Super-Elmar is different (see under #6): no problems with older or even old M-bodies, but misalignment of the M9-rangefinder in the infinity position.

[ho_co]

Wasn't precisely this the reason why long ago Leitz warned against using the Summicron-C and Elmar-C lenses on M bodies?...

Exactly, John.

 

But I think the reason they can get away with it today is that we're talking about extreme wide angles. The rangefinder problems Tim experienced are real, but so is the lens' infinity stop. IOW, for normal use by a photographer who understands the ramifications of the sloped cam, there is no drawback.

 

... Or maybe Leitz just lied to us about about the C lenses.

No way. I've got several M cameras whose cam followers don't line up with C lenses.

[lct]

The Summarit 35/2.5 has a slopped cam as well. Doesn't worry me at all i must say as i've never had the least focus problem with my 3 copies of the Summicron-C 40/2 on four M bodies and two Epsons.

[LeicaPassion]

My 24mm Elmar focuses to infinity with no problem at all. I chose the 24 over the 21 because it offers a more realistic perspective, IMHO. As others have written, it's a superb lens.

[chimray]

My German friend just told mr Leica will have recall for this new 21mm due to focus issue, anyone also have this news ?

[LVSBB6]

My experience with the 18mm Super-Elmar is different (see under #6): no problems with older or even old M-bodies, but misalignment of the M9-rangefinder in the infinity position.

 

Anyone know why the 18mm Super-Elmar would be mis-aligned on M9 in the infinity position?

[jaapv]

Because it needs to be adjusted? Mine lines up perfectly. To throw some confusion into the discussion: I think the Summilux 24, Summilux 50 asph and SuperElmar 18 are a very good match...I jumped the 35 and 21 focal lengths deliberately.

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Hallo,

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