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Confusion over 90mm Leica lenses and APO?
Old 07-27-2011   #1
animefx
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Confusion over 90mm Leica lenses and APO?

I'm still waiting for my M8 to arrive while I'm considering what lens to get other than my 40mm f/2 rokkor-m I already own.

I've been seeing some AMAZING look photos from the various Leica 90mm lenses... Sometimes they are specified which version, sometimes not. I have to admit I'm a little confused about a few things with Leica's 90mm lenses, if anyone can clear this up I would be most appreciative.

- Which 90mm Leica lenses are still in production?

- I've heard there are one or two 90mm lenses that have back focusing problems with the M8 and M9 or somehow aren't "meant" for digital... Is this true? If so which version(s) of the 90mm are they referring to?

- Also, what is APO? Is the APO also an ASPH lens? Is APO better than ASPH or do they have nothing to do with eachother?

If I get a 90mm I want it to be sharp corner to corner as I might use it for landscapes and portraits as well. I've seen photos from the 90mm elmar-c for the Leica CL / Leitz Minolta CL (or CLE) and I'm not overly impressed like I am with my 40mm f/2. I also heard the 90mm summarit is the worst of the 4 summarit lenses, so I might avoid that too (I am interested in the 75 summarit however.)

If there is anything else I should know about 90mm lenses please let me know, I'm looking for a nice balance between sharpness and middle of the road price (for Leica) if possible.
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Old 07-27-2011   #2
andredossantos
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From what i understand, a lens marked APO (apochromatic) is made partly with "low dispersion" glass which corrects aberrations. A designation of ASPH means that a lens is built with aspherical elements, which also makes for a corrected image. It may be obvious I'm not a tech guy and my answers were pretty shoddy. However, unless you have an interest in the nitty gritty just assume these designations mean you're getting a high quality piece of glass!

I have the 90mm version 1 Summicron. It's the size of a pipe and it heavy but it's a stellar performer and I quite like the "older" style (read: not APO and not ASPH) rendering. In the its a personal decision and a good way to think about it is:

image rendering style vs lens size vs cost
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Old 07-27-2011   #3
Tim Gray
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The latest 90 Summicron is APO and ASPH. It's Leica's only 90 for the M system that is APO or ASPH. So when you see someone refer to the Leica 90 APO or Leica 90 ASPH or the 90 AA, it's the same lens, the most recent Summicron.
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Old 07-27-2011   #4
Chuck Albertson
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The 90 AA Summicron is in production, as is the 90 Summarit (f/2.5). The 90 AA is a marvelous lens, but the Summarit is considerably cheaper and not to be sniffed at.

Don't know anything about back-focus problems.
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Old 07-27-2011   #5
Juan Valdenebro
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I use version 2 (yet big, wonderful bokeh, collapsible hood, not excessively sharp for portraits).
Some people prefer version 3 because it's smaller and a bit sharper wide open... I like to think if the lens is smaller, some of the OOF character I like in my lens, did change , but not sure, as I've never compared both doing the same shot...
If you don't enjoy a bit of softness for wide open portraits, and you're after sharpness, get the current one, which I've heard is the best one for landscape...

Cheers,

Juan
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Old 07-27-2011   #6
kzphoto
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Wikipedia:
http://en.wikipedia.org/wiki/Apochromat

APO stands for Apochromatic. Read up! APO lenses are great for digital.

FYI, the new 50 f/1.4 Summilux ASPH and the 75 Summicron ASPH are both APO lenses, though they are not advertised as such.

~k.
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Old 07-27-2011   #7
ferider
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Currently in production, I believe, are 90 and 75 Summicron (APO & ASPH), and 90 and 75 Summarit (spheric design).

The 90 Elmarit-M (spheric) was discontinued just recently (2008).

Non-Leica M teles until recently in production are CV 75/2.5, CV 75/1.8, CV 90/3.5, ZM 85/4, ZM 85/2 (discontinued 2 months ago ?).

They are all great. Have a look at the flickr M-mount forum (see my signature) for sample photos taken with any of the above lenses.

Unless something is wrong with your M, they should all work on digital. Don't discard 75, in particular with crop factor.

Best,

Roland.

Last edited by ferider : 07-27-2011 at 15:56.
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Old 07-27-2011   #8
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Besides the 90/2 Summicron, there also 90/2.8 Elmarit-m, 90/2.8 Tele-Elmarit, 90/4 Elmar
Just as with the varieties of Summicron there may be several style or formulas of each of these.
The 90/4 Elmar-C you're already aware of.
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Old 07-27-2011   #9
The Meaness
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Quote:
Originally Posted by ferider View Post
Don't discard 75, in particular with crop factor.
This is great advice, especially if you've never used an RF before. I use a 50mm on the M8 as a portrait lens, since the crop factor brings it to 67mm fov. Personally, I have a real hard time imagining how I'd rely on the small 90mm framelines consistently to compose.

If you've used RF cameras before and know what you're looking for, I apologize - I know you didn't post asking for FL suggestions. However, if you haven't, you may want to wait until you get the camera in your hands and you can look through the VF to see the difference between the 50, 75, and 90 framelines.

Good luck!
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Old 07-27-2011   #10
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Don't forget the current Elmar macro, a wonderfully sharp lens, collapsible, and small if you can live with the maximum of f 4.0. Unfortunately, it's not cheap either new or uses.
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Old 07-27-2011   #11
animefx
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Thanks for the info guys. I will probably wait until I upgrade to a. M9 or M10 a few years from now before going for a 90mm. I think 75mm is as long as I'll want to go on then M8 due to the crop factor.
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Old 07-28-2011   #12
ramosa
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Quote:
Originally Posted by The Meaness View Post
This is great advice, especially if you've never used an RF before. I use a 50mm on the M8 as a portrait lens, since the crop factor brings it to 67mm fov. Personally, I have a real hard time imagining how I'd rely on the small 90mm framelines consistently to compose.

If you've used RF cameras before and know what you're looking for, I apologize - I know you didn't post asking for FL suggestions. However, if you haven't, you may want to wait until you get the camera in your hands and you can look through the VF to see the difference between the 50, 75, and 90 framelines.

Good luck!
+ 1 ... This is why I ended up with an 80 instead of 90 on my M8. In fact, with the M8 crop, I really do not like a 50mm lens, which has a 67mm field of view. My Lux 50 is a super lens, but IMO it's not a good focal length on the crop.
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Old 07-28-2011   #13
venchka
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And now for something completely different........

In the great bang for buck/cheapo fabulous lens department: Nikkor 8.5cm/2.0 lens. A very inexpensive way to find out if the 85-90 focal length floats your boat. In the same vein, and 1 stop slower: the original Leitz 90mm f/2.8 Elmarit. The one with a band of vulcanite at the base near the lens mount. Wonderful classic rendering. Sharp without causing your eyes to bleed. Last, but not least, the last 90mm f/2.8 Elmarit-M is as sharp and apochromatic as anyone needs in a thoroughly modern image making machine.

He said, comfortable in the knowledge that all 3 are tucked safely in the rangefinder bag.

ps: If you want the real 85-90 experience, buy a film body.
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Old 07-28-2011   #14
ka7197
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Quote:
Originally Posted by animefx View Post
Which Leica M 90 mm lenses are still in production?
Only one葉he Summarit-M 90 mm 1:2.5. [EDIT: No, it's two: the Summarit-M 90 mm 1:2.5 and the Macro-Elmar-M 90 mm 1:4 (thanks to Tim for the hint)]

Officially, there's another current 90 mm lens: the Apo-Summicron-M 90 mm 1:2 Asph ... however this one has been unavailable for purchase for the recent one or two years. It seems it really is not in current production even though it is still listed in the catalogs/web site/price lists. Lenses are made in batches of several hundred or 1,000 pieces per batch, and it seems the last batch was made years ago. No-one knows iwhen the next batch is going to be produced, or if there will be a next batch anytime soon in the first place. Rumour says a successor to the "current" Apo-Summicron-M 90 Asph (with floating elements) is under development, and the "current" one is still current only because Leica has not yet announced the successor model. But that's just that預n unofficial, unverified, uncomfirmed rumour out of thin air. Sounds plausible to me, though ...


Quote:
Originally Posted by animefx View Post
I've heard there are one or two 90mm lenses that have back focusing problems with the M8 and M9 or somehow aren't "meant" for digital ... Is this true?
No, it's not. It's just nonsense spread by clueless people. As a matter of fact, any telephoto lenses (in particular, 90 mm and 135 mm) are very finnicky to adjust properly on a rangefinder. So the odds are that an arbitrarily picked 90 mm from the used market might be slightly out of spec. But you can always have it adjusted to match your camera by Leica's Customer Service or any skilled camera service technician.


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Originally Posted by animefx View Post
Also, what is Apo? Is the Apo also an Asph lens?
Apo is short for apochromatic. In the narrower sense it means a lens that is colour-corrected for three colours (as opposed to the usual two). In a broader sense, it means a lens with particularly low chromatic aberrations.

Asph is short for aspherical and means a lens which includes at least one aspheric optical element. Aspheric element are difficult to produce so they are either poor quality or expensive. In the latter case (expensive) they greatly reduce all kinds of spheric aberrations. So they are, in a way, just the contrary to apochromatic預po and asph are two entirely different things but when both are combined in one single lens then they will complement each other wonderfully.


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Originally Posted by animefx View Post
I also heard the Summarit-M 90 mm is the worst of the four Summarit-M lenses, so I might avoid that too (I am interested in the Summarit-M 75 mm however).
Even if the 90 mm really was the worst of the current Summarit-M line it still doesn't mean it was a bad lens which was to be avoided. It would just mean the other three were even better擁f it was true in the first place (it isn't).

Both the 75 mm and 90 mm Summarit-M lenses are excellent容ven though at the end of the day the Apo-Summicron-M Asph versions of these two focal lengths are slightly better overall (at more than twice the price, they really should!) ... however not better in every aspect. With both Summarit-M lenses you won't be disappointed for landscape and portraiture work.


Quote:
Originally Posted by animefx View Post
If there is anything else I should know about 90 mm lenses please let me know, I'm looking for a nice balance between sharpness and middle of the road price (for Leica) if possible.
The Elmarit-M 90 mm 1:2.8 (the latest version with built-in retractable hood) is just as good as good as the 90 mm lenses discussed above, just a little slower. It has been discontinued from production only a few years ago. The Summicron-M 90 mm (non-Apo, non-Asph) is pretty good, too, and not very expensive in today's used market. However it's not particularly sharp at full aperture溶ice for soft-ish lady's portraits but for landscape work it should be stopped down a little.

But please keep in mind預ny 90 mm lens can be slightly off on your camera, even a new one right out of the box. If it is then send it in for an adjustment.

Last edited by ka7197 : 07-28-2011 at 14:27.
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Old 07-28-2011   #15
Tim Gray
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Quote:
Originally Posted by ka7197 View Post
Only one葉he Summarit-M 90 mm 1:2.5.

Officially, there's another current 90 mm lens: the Apo-Summicron-M 90 mm 1:2 Asph ... however this one has been unavailable for purchase for the recent one or two years. It seems it really is not in current production even though it is still listed in the catalogs/web site/price lists.
As stated above, I think the 90 Macro is still being made too.
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Old 07-28-2011   #16
ka7197
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Originally Posted by Tim Gray View Post
As stated above, I think the 90 Macro is still being made too.
Oh yes, you're right. Forgot that one ... which is funny as the Macro-Elmar-M 90 mm 1:4 is a very interesting lens actually. Tiny, sharp, and will reach the highest magnification of all Leica M lenses (short of using a Visoflex).
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Old 07-28-2011   #17
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Yeah, it's a cool lens. It's the 90 I went with.
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Old 07-28-2011   #18
Juan Valdenebro
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When you focus close a 90 Summicron wide open, background is really OOF, even very close to the focused point, but what surprised me the most about mine, was the DOF in such case: almost nothing! I think I remember, when I did the test after receiving the lens (tripod and a ruler) no more than two millimeters were on focus... And even focusing carefully with a Bessa-T (longer effective baselength than most Leicas, and tripod as I said) I couldn't get focused the very same point of the ruler, although the three images I did for every focused distance/f-stop, in this f/2 1mt case were close... And in real life, it's really hard to get on focus a precise point on someone's face: sometimes you will, but you'll never know for sure until you explore the image very close... So, to me my 90 f/2 is basically an effect lens: great classic bokeh/portrait lens, but always considering it's hard to focus in the closest range when wide open... Another fact is it's a 90, so handheld it isn't easy to get sharp results unless fast speeds are used... All in all, if you think of using the lens for other things more than portraits with lots of OOF zones on the image, a smaller, lighter 90 lens makes more sense, like the 2.8 or 4 Leica ones, or the 3.5 CV... Other great options for portraiture are the 1.8 85 Canon and the 1.8 75 CV...

My 90 Summicron is my hardest to focus lens... And I see very well: I focus perfectly my 40 at 1.4 even with my R4M! And stopping down doesn't help as much as I imagined before owning it: going to 2.8 or 4 doesn't change things to much if you're focusing close...

All that, in case you have not used a 90 f/2 RF lens... If you have, sorry for the long description...

Cheers,

Juan
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Old 07-29-2011   #19
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Most apochromatic (Apo) lenses bring 3 colours to identical focus -- hence the paint-filled, engraved red, green and blue lines on the mount of both original and modern Apo-Lanthars -- instead of just the red and blue of an achromat, but a few apparently bring four colours to a common focus (I don't know which lenses: Brian might). It is perfectly possible to build apo lenses with only common (spherical) curves.

Aspheric surfaces allow better correction with the same number of elements (glasses), or the same correction with fewer elements. There are three kinds: ground and polished glass (the most expensive, used only by a very few manufacturers in a very few lenses), moulded glass (hard to do well, and suited only to small glasses if you want maximum quality, but good enough for Leica in some applications) and 'hybrid', a glass spherical element with 'optical resin' (plastic, if you're being rude) moulded on to it.

Hybrids have not been around long enough to know much about their durability, but as far as I am aware, that is the only major concern that has ever been raised about them. Apparently they offer rather fewer options to the lens designer than glass aspherics, but they still offer better correction than spherical surfaces. Certainly, I've has the 90/3,5 Apo-Lanthar since it came out, and it's still an excellent lens. That's from the point of view of someone who also owns a 90 Summicron pre-aspheric and a 75 Summicron (aspheric, because they all are).

Cheers,

R.

Last edited by Roger Hicks : 07-29-2011 at 04:45. Reason: typo
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Old 07-29-2011   #20
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Quote:
Originally Posted by Juan Valdenebro View Post
When you focus close a 90 Summicron wide open... it's really hard to get on focus a precise point on someone's face...I focus perfectly my 40 at 1.4...
No problem with 40 (or 50) mm lenses at f/1.4 but 90's exceed the accuracy range of the M8 at f/2, due to its 0.68x VF and 1.33x crop factor. Same for Bessas, Leica CL, Epson R-D1 and 0.58x film Ms BTW.
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Old 07-29-2011   #21
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APO aint apochromatic, though.

Here: http://leica-users.org/v13/msg13490.html Erwin Puts points out:
"Now there is no industry norm that first describes which glasstypes you have to use to make a lens an "apo" and secondly describes which numerical deviations are required for such a designation."

If you use the absolute definition: i.e. an optical system corrected so that
it gives three images of identical size for three different spectral lines
or regions, you'll find that there are no APO lenses in current production, including those made by Leica. There are, however, several lenses that
are lens that has been corrected to a greater degree than in most other
lenses for the three primary spectral colors, including the R&M 90 APO
ASPHs. The differences in image size and therefore the 'degree' to which
the Leica APOs are apochromatic is an interesting study in itself. One thing is for
certain, they are better colour corrected (closer to the absolute APO) than
the majority of other current lenses.

Anyone with sufficient masochistic tendencies can calculate the (apo)chromatic error.

The other little-discussed influence is that the chromatic error decreases with stopping down, at least until diffraction makes it worse. At f8 or thereabouts, it is minimal, in all optical systems.

The true APO lenses for my microscopes cost about twice as much for a lens as an M9, but the lenses are about the size of your thumb and don't have an aperture or focusing mechanism. It is very difficult to achieve with camera lenses and not really necessary. 'Good' correction, such as is offered by the Leica APOs (excellent, really) will very, very rarely show any chromatic abberration.

Superachromatic lenses are corrected for four spectral lines but are mostly theoretical unless you have access to the kind of lens systems used in space, high end military . http://en.wikipedia.org/wiki/Superachromat There are Zeiss Superachromats for the Hasselblad: http://lenses.zeiss.com/photo/en_DE/...t56350cfe.html but I don't know how fully corrected they are across all four spectral line. Very well, I guess, but I don't know if they really do all focus to a single point.

Marty

Last edited by Freakscene : 07-29-2011 at 02:07.
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Old 07-29-2011   #22
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Quote:
Originally Posted by Roger Hicks View Post
75 Summicron (aspheric, because they all are).
There is also the Leitz Midland 75/2.4 APO, which is not asph, but it is incredibly rare.

Marty
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Old 07-29-2011   #23
ka7197
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Quote:
Originally Posted by Roger Hicks View Post
Most apochromatic (Apo) lenses bring three colours to identical focus ...
No, most don't. In fact, most lenses designated 'apo' really are achromats only, not apochromats in the word's narrower sense, but with a lower-than-usual secondary spectrum (i. e. very low residual chromatic aberration). True apochromatic lenses for photographic purposes exist but are very rare.


Quote:
Originally Posted by Roger Hicks View Post
... hence the paint-filled, engraved red, green and blue lines on the mount of both original and modern Apo-Lanthars ...
That's just a marketing ploy, supposed to make you believe these were true apochromats. Obviously it worked ...


Quote:
Originally Posted by Roger Hicks View Post
... but a few apparently bring four colours to a common focus ...
Those are superachromats, and they are even rarer than true apochromats. They might be common (kind of) for industrial, scientific, or military purposes but for photography I am aware of only two superachromats, the Zeiss Super-Achromat 250 mm and 350 mm CFE telephoto lenses for Hasselblad medium-format cameras.


Quote:
Originally Posted by Roger Hicks View Post
It is perfectly possible to build apo lenses with only common (spherical) curves.
As a matter of fact, the curvature of the elements has nothing to do with chromatic aberrations or the correction thereof, so aspheric elements won't help against chromatic aberrations. Clever combination of different kinds of glass (different ratios of refraction vs. dispersion) does. Aspheric elements help against spheric aberrations only. As I said: apo and asph are two entirely different things.


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Originally Posted by Freakscene View Post
The other little-discussed influence is that the chromatic error decreases with stopping down, at least until diffraction makes it worse. At f/8 or thereabouts, it is minimal, in all optical systems.
This is only half-way true. Longitudinal chromatic aberrations will get reduced by stopping down but lateral chromatic aberrations won't.


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Originally Posted by Freakscene View Post
'Good' correction, such as is offered by the Leica 'apochromats' (excellent, really) will very, very rarely show any chromatic abberration.
Sigh ... if only that was true. Unfortunately, it isn't. When looking closely then you'll see both longitudinal and lateral chromatic aberrations in pictures taken with current Leica Apo-Summicron-M Asph or Apo-Telyt-M lenses just as with any non-apo lens. Sure, their chromatic aberrations are pretty low, definitely lower than in non-apo lenses, but not lower by one or more orders of magnitude ... it's maybe half or one-third as much. That is a significant improvement for sure but still far from perfect.
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Old 07-31-2011   #24
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Originally Posted by ka7197 View Post
This is only half-way true. Longitudinal chromatic aberrations will get reduced by stopping down but lateral chromatic aberrations won't.
Of course, but this is why manufacturers choose to control different aberrations differently. You can detect some CA in the leica APO lenses wide open, but while at f8 I can measure in on my optical bench or detect it using the colour picker tool in PS at 100% pixel view, I can't see it in prints.

Quote:
Originally Posted by ka7197 View Post
Sigh ... if only that was true. Unfortunately, it isn't. When looking closely then you'll see both longitudinal and lateral chromatic aberrations in pictures taken with current Leica Apo-Summicron-M Asph or Apo-Telyt-M lenses just as with any non-apo lens. Sure, their chromatic aberrations are pretty low, definitely lower than in non-apo lenses, but not lower by one or more orders of magnitude ... it's maybe half or one-third as much. That is a significant improvement for sure but still far from perfect.
They're good enough for me, although I must admit my own interest in CA only goes as far as wanting sharper edges, because I mostly use B&W for my own photography and when I work professionally it isn't using Leica camera lenses.

If you can show us an image from a leica APO that shows clear chromatic aberrations that can't be attributed to sensor bloom, I'd be interested to see them.

Marty
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Old 07-31-2011   #25
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An Apochromat is corrected for three wavelengths, usually within the three primary colors, three zero crossings where the chosen wavelengths are in agreement. That is the accepted optical definition. An Achromat is corrected for two wavelengths to have zero crossings. The deviation from the crossings varies greatly among lenses. A Super-Achromat is corrected for four crossings. I suspect most people use "color" and "wavelength" interchangeably. The optics are corrected for specific wavelengths to have zero-crossings, not ranges of colors to all agree perfectly.

The IR index of the type 1 Rigid Summicron, an Achromat, is within the F2 DOF marks. Many lenses, also Achromats, have the IR index at between F4 and F8. The deviation from the crossings is much higher than the Summicron.

Some manufacturers use the term loosely, a highly corrected Achromat with low deviation from the crossing being labeled "APO". It is not, the difference may not be noticeable, but if you run the calculations- it was designed as an Achromat and the rest is marketing.

Last edited by Brian Sweeney : 07-31-2011 at 19:19.
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Old 07-31-2011   #26
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Quote:
Originally Posted by Brian Sweeney View Post
I suspect most people use "color" and "wavelength" interchangeably. The optics are corrected for specific wavelengths to have zero-crossings, not ranges of colors to all agree perfectly.
The normal technical terminology is "spectral lines" and there is no standardised approach there for lenses either - thre three or four spectral lines with zero crossings of an apo or superchromat may not be the same spectral lines between manufacturers.

Where the IR index lies, is, I think, an interesting point - it is possible to have a very lens that is very well corrected for visible light that is not well corrected outside that range, and vice versa - the new Summicrons are better corrected for the visible range, but shift noticeably more in the IR range.

Certainly interesting if you're shooting IR.

Marty
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Old 08-01-2011   #27
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The optical design software that my engineers used (ASAP 11.0) asked for input in wavelength. The patent for the Pentax Ultra-Achromat uses wavelength in microns.

I'm used to seeing spectral lines with names for the transition that produces them. Perhaps different software packages for certain applications allow for specific emission lines to be input for zero-crossings, that would make sense in many applications.
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Old 08-01-2011   #28
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Originally Posted by Brian Sweeney View Post
The optical design software that my engineers used (ASAP 11.0) asked for input in wavelength. The patent for the Pentax Ultra-Achromat uses wavelength in microns.

I'm used to seeing spectral lines with names for the transition that produces them. Perhaps different software packages for certain applications allow for specific emission lines to be input for zero-crossings, that would make sense in many applications.
The software that we use (supplied by Zeiss) is set up so that we input those spectral lines - it seems that it can be heavily customised, but we only tend to use it for a single purpose. I haven't used or seen ASAP for a long time, but I remember now that it worked that way - and I can see a lot of situations where that could be more convenient too.

Marty
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Old 08-02-2011   #29
1joel1
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I have an older 75mm Summilux that I used with the R-D1. However, I just sold that camera and am only a few days away from my "new" M8 arrival. The 75 was perfect for many uses on the Epson and I would imagine that it will still be the best lens on the M8. I use it as a normal lens most of the time as I "see" things more telephoto than wide.

Joel
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Old 08-02-2011   #30
Tom Niblick
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Originally Posted by animefx View Post
Thanks for the info guys. I will probably wait until I upgrade to a. M9 or M10 a few years from now before going for a 90mm. I think 75mm is as long as I'll want to go on then M8 due to the crop factor.
I loved the 90 Elmarit M on my M8. The EFV is 120 which is perfect for tight head shots and a good general purpose telephoto. But I have to admit, it's pretty fine on the M9.
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