OT - Voigtlander SL 125mm f2.5 Apo-Lanthar Macro

[Kev T]

Sorry for being somewhat off topic, but I don't know where-else I can find out more about this lens. I'm based in Singapore with no official agent for C/V here...

I've been shopping around for a 100mm class macro lens for my Nikon F mount Kodak Pro SLR/n DSLR, the obvious choice is the new Nikon 105mm f2.8 ED VR Micro, but given its USD1.2k - 1.4k price and not usable with my film FM-2T body makes it less palatable...

Hence I'm looking around for the Voigtlander SL 125mm f2.5 Apo-Lanthar Macro, and would appreciate hearing from those who have this lens with their film SLRs or even FF DSLRs...

How is this lens optically? Is it true that it is able to maintain f2.5 at 1:1 magnification? Can anybody post images from this lens? Boke?

Thanks in advance,
Kev

 

[Mazurka]

Is it true that it is able to maintain f2.5 at 1:1 magnification?

No lens can do that. Effective aperture decreases with increased extension.

Unless you must have a new lens, why not get the 105/2.8 Micro-Nikkor? Tamron's 90mm Macro lens (still current) also enjoys a great reputation.

 

[Dougg]

Hi Kev -- From what I've heard on Photo.net and on the CVUG e-list, this lens is really sweet; sharp with nice character. Surprisingly large in size too. The laws of optics decree 2 stops extra exposure will be needed at 1:1 magnification (for any unit-focusing lens). Your camera's TTL metering will handle this compensation automatically, though...

Long macro lenses are favored to give extra disatance from the subject, so you're not right on top of it, maybe shading its light. But on a dSLR, a 50mm macro or 85mm lens would be "long", and 125mm would be very long! 🙂

 

[Mazurka]

But on a dSLR, a 50mm macro or 85mm lens would be "long", and 125mm would be very long! 🙂

Doug, you obviously missed the double-SLR designation which probably means the sensor is 24x36mm. 😛

 

[Kev T]

Constant aperture macro!

Constant aperture macro!

No lens can do that. Effective aperture decreases with increased extension.

Unless you must have a new lens, why not get the 105/2.8 Micro-Nikkor? Tamron's 90mm Macro lens (still current) also enjoys a great reputation.

Hi Mazurka,

I heard from somewhere that this lens has a mechanical aperture compensation just like 'constant aperture' zoom lenses, where the aperture blades opens up with zooming, except in this case the aperture blades opens up as you focus towards the macro range...

this is also new to me and I'm checking around to confirm this feature on this lens...

Kev

 

[Kev T]

Hi Kev -- From what I've heard on Photo.net and on the CVUG e-list, this lens is really sweet; sharp with nice character. Surprisingly large in size too. The laws of optics decree 2 stops extra exposure will be needed at 1:1 magnification (for any unit-focusing lens). Your camera's TTL metering will handle this compensation automatically, though...

Long macro lenses are favored to give extra disatance from the subject, so you're not right on top of it, maybe shading its light. But on a dSLR, a 50mm macro or 85mm lens would be "long", and 125mm would be very long! 🙂

Hi Doug,

I've just tried explain the 'constant' aperture feature of this lens to Marzuki, but at the same time, I was hoping to get confirmation of this fact from someone who owns or had used this lens. I'd read this from somewhere while researching this lens... doesn't seem to have much info on it anywhere... Stephen? is the 'constant' aperture at macro focus distance feature true?

The 125mm focal length works for me as my Kodak SLR/n DSLR is indeed a full frame 36mm x 24mm (13.8Mp resolution) imaging sensor camera, so there is no crop factor involved, but the camera is sensitive to lens performance at image frame's edge.

This lens is built by C/V to meet the old Nikon Ai-s lens mechanical indexing system, but the Kodak DSLR lacks the Ai-s indexer, so I'll have to use an external meter with this lens, which I can live with.

On the other hand, Nikon's latest 105mm f2.8 Micro lens has all the AF, VR, ED glass, Nano crystal coating doodah, but does not have a physical aperture setting ring on the lens, which precludes its usage with my all mechanical FM-2T body, so therefore I am bualking at spending so much for a lens I can't use with all my Nikon bodies.

From what I've heard thus far, and including your reply, this C/V Apo-Lanthar is my best bet, from an optical performance point of view.

Kev

 

[Dougg]

Sorry, Kev, for misunderstanding a couple points in your question. Didn't realize the Kodak was 24x36... A constant aperture feature would be very tricky, and I think it would require internal focusing rather than unit focusing. I have been tempted by this Apo-Lanthar but put off by its massive size. I hope Stephen or someone with this lens can offer a definitive answer on this question, but it seems to me if it were true then it would be trumpeted proudly in the lens's description on the CameraQuest site. 🙂

 

[Mazurka]

in this case the aperture blades opens up as you focus towards the macro range...

Kev, the decreasing effective aperture with extension is a result of increased focal length. If you look at the diameter of this f/2.5 lens, you would realize it's not possible.

The lens would have to be a lot faster (and its barrel as wide as a tree) in order to have a maximum aperture of f/2.5 at 1:1 mag (2 stops according to Doug), or its focal length would have to be 63mm at infinity with the present barrel size.

it seems to me if it were true then it would be trumpeted proudly in the lens's description on the CameraQuest site. 🙂

Doug's right. Even Cosina's own page doesn't mention any special aperture mechanism, only 3 floating elements for close range correction.

If your kanji and katagana are not up to the task, just use Babel Fish or Google to translate the page.

 

[Kev T]

Hi Marzurka,

Much as it sounds impossible, here is the thread I was reading by a Malaysian photographer reviewing it...
http://www.photomalaysia.com/forums/showthread.php?t=7718

I must say I'm not entirely sure, which is why I'm asking here for confirmation... However, the lens is certainly oversized for its specifications, consider this:

125mm f2.5, the front filter size is 58mm which sounds reasonable enough, but the final outer diameter of the lens is a massive 76mm... Is that sufficient to house the constant aperture mechanism, I don't know yet... Maybe. the lens does weigh in at 690 grams which is certainly somewhat heavy even allowing for the 20-25mm longer focal length over comparable macro lenses. The old Nikon 105mm Micro f2.8 weighs 560 grams, and their new 105mm Micro with VR ED and AF-S is 720 grams.

I don't read Kenji, and I did try online translation of the C/V web-page describing the lens... The first sentence goes:

-Shutter chance is not let escape, o of all the photographing distance corresponds ... (untranslated Japanese phase)

Note the line ...all the photographing distance... That gentleman was the translated first sentence, and if that is describing the constant macro aperture, then I'd say they're shouting about it. I just wish the tranlation could be better!

Kev

 

[Kev T]

Just a further thought, the conjecture on whether this lens is indeed constant aperture in the macro range is not a deal-breaker for those, myself included who is considering to acquire this lens.

However, as Doug notes twice above that it is oversized and overweight for what we'd expect a 125mm f2.5 lens to be sized & weighted...

At the end of the day it is the optical performance, and here Stephen's description of this lens suggest comparison with far more costly 100mm macro lenses from Solms or Oberkochen!

However, my curiosity about the supposedly constant macro aperture is certainly piqued! As are both yours and Doug! Someone who actually has this lens please talk to us already! 🙂

Kev

 

[Mazurka]

Much as it sounds impossible, here is the thread I was reading by a Malaysian photographer reviewing it...
http://www.photomalaysia.com/forums/showthread.php?t=7718


125mm f2.5, the front filter size is 58mm which sounds reasonable enough, but the final outer diameter of the lens is a massive 76mm... Is that sufficient to house the constant aperture mechanism,

I don't read Kenji, and I did try online translation of the C/V web-page describing the lens... The first sentence goes:

-Shutter chance is not let escape, o of all the photographing distance corresponds ... (untranslated Japanese phase)

Note the line ...all the photographing distance... That gentleman was the translated first sentence, and if that is describing the constant macro aperture, then I'd say they're shouting about it. I just wish the tranlation could be better!

Kev

First, why don't you ask khoking who made this claim how s/he obtained this piece of information? Was it by experiment (same shutter speed and aperture indicated both at infinity and 1:1 given the same EV), conjecture or mere heresay?

Second, what is claimed actually is not "constant aperture", because aperture is measured relative to focal length. The physical size of the aperture must be enlarged (by two stops according to Doug) at 1:1 to keep the same relative f/2.5, because the focal length becomes 250mm at 1:1, and that requires a 100mm aperture!

The nominal focal length and aperture (125/2.5) are measured at infinity. That means the maximum aperture diameter is 50mm, in line with a 58mm filter size. Keep in mind that for 1:1, you need a lot of extension and a much longer helical. The fact that it is manual focus means the helical is not shortened and lightened as necessitated by fast AF response. Together with the number and size of the glass elements, and you have the girth and weight.

As for the first paragraph (which doesn't mention aperture at all) of Cosina's page, this is how I re-write the Babel Fish translation into proper English: it simply means "With the Macro Apo-Lanthar, you don't have to change lenses from shooting scenery to a single flower, hence you don't lose the decisive moment. Optimal quality is maintained at 1:1 copying, as well as portrait and far distances. This is a new-age macro lens, specially designed by Cosina to maintain high performance at all distances."

 

[Dougg]

Mazurka's argument makes good sense to me, and I've been assuming this lens's large size has to do with multiple concentric focusing helixes necessary to get the full five inches of extension! These days it's not uncommon for macro lenses to have moving elements just to correct optical problems that arise at close distance for a lens designed for top performance at infinity. I believe Pentax's 135mm f/4 macro for the 67 system doesn't have moving elements, and it has been criticized as optimized for close work at the expense of performance at infinity. OTOH, the new Pentax 67 non-macro 75mm f/2.8 asph focuses unusually close, and does have at least one element moving to correct for that close distance. So this sort of thing is done...

Yet the earlier comment about constant-aperture zooms sticks in my mind. Do they actually design a faster lens then close the aperture smaller as it zooms wider? It might be possible to design a zoom or a macro such that moving the internal lens groups doesn't move the aperture plane relative to the film. (Actually I think the old front-cell focusing lens type with leaf shutters is an example, but didn't focus very close). Then the film would "see" a constant size hole letting the light in... rather than one disappearing into the distance as with unit-focusing. Dunno, just a thought.

Edit: Well, reading that referenced review by Khoking, he says it extends 64.2mm from 88.2 to 152.4mm. I thought it would have to extend an amount equal to its focal length to get to 1:1, but maybe I'm wrong; 64.2mm is about half its focal length.

 

[Mazurka]

reading that referenced review by Khoking, he says it extends 64.2mm from 88.2 to 152.4mm. I thought it would have to extend an amount equal to its focal length to get to 1:1, but maybe I'm wrong; 64.2mm is about half its focal length.

I believe that info is taken from the Cameraquest page and let's assume it's correct. The shorter-than-expected extension could well be a function of the floating elements.

And suppose the focal length at 1:1 is about 1.4 X 125mm = 175mm. To maintain f/2.5 at this focal length, the aperture has to be 70mm, still way too large for the lens' present physical size to include the necessary helicoids and structural support.

In response to Doug's comments regarding zooms:

In this age of auto focus, most -- if not all -- "zoom" lenses are varifocal designs rather than parfocal. The change in focus at different focal lengths are just corrected by the AF system. You would expect a varifocal lens with a "constant maximum aperture" to be a lot easier to design and make than a true zoom (i.e. parfocal.)

The way my two "fixed aperture" manual focus zooms work, it does look like they were designed with the biggest aperture at the longest focal length first, then the physical aperture is reduced accordingly as it zooms wider.

Of course this has very little to do with the Apo-Lanthar. 😛

 

[Kev T]

Mazurka,

You've made a rather convincing case that this lens does not remain at ff2.5 when focused to 1:1... I'm quite certain you're correct in your assessment on the implausibilty of the 'constant aperture' macro lens.

As I've mentioned earlier, what KhoKing describes sounded fantastic which made me gave pause. Would I decide against this lens if this were not so? Surely not!

I was already interested in acquiring this lens prior to reading KhoKing's description, and none of us ever had a macro lens that maintained its aperture settings towards the macro range anyways...

Cordially,
Kev

 

[Mazurka]

Kev, this is a fast and unique macro lens. If you like the focal length (much closer to 135mm than 105 actually), do a lot of close up work, don't mind the weight and can afford it, why not? You can get it from Cameraquest which is probably cheaper than a local store, if any. I guess the point of Doug's and my posts is "don't have any unreasonable expectations about f/2.5 at 1:1."

But if you want it to double as a portrait lens, you need to decide whether it's too long -- it sure is if used indoors. There is also the question of background bokeh at portrait distances. IIRC the Micro-Nikkors don't do that well in this respect. There should be no problem in the macro range, however.

 

[Lear]

Just a note here, he states its the fastest macro ever made, not true, look at the olympus OM line.

I belive he states it 2.5 constant just because thats what it shows on the lens. On the micro nikkor 60mm it shows 2.8 on the ring but F5 or so in te display.

I would ask Stephen of cameraquest.com directly.

 

[Kev T]

Hello Mazurka & Lear,

Thanks for your valued input Mazurka, I concur mostly with what you say... When shooting in studio, with my 80-200 f2.8 Nikon zoom, I do find myself setting the lens at 135mm most of the time for tight head shots, being my style if the shoot is not fashion, so 125mm is ok for me, and certainly ok if I need to shoot macro subjects such as watches or jewellery. This is for lower budget assignments that don't involve shooting with MF + digital backs or LF.

Now on to the shopping part 🙂 ! if i don't find it locally or the prices are ridiculous, I'd be certain to touch bases with Stephen.

Thanks also Lear,

I suppose it depends on the perspective of the dealers advertizing,... You're right that the OM Zuiko 90mm f2.0 was the fastest shot tele macro ever, but operative word is WAS, since we can't buy one from the store anymore. Furthermore, for macro lenses between the focal length of 90mm to 180mm made by various manufacturers today, none exceed f2.5 wide open.

On another note, with macro lenses, the aperture ring does not 'move' to indicate change of aperture values as we focus closer towards the macro range, at least I've never seen this happen with any older macro lenses I've ever used... if the lens is equipped with electro-linkage, then we can see the VF display indicate the change in values.

Regards,
Kev

 

[alfcnka]

This lens is discontinued. You can contact Dr Joseph Yao from HongKong <joseph@yao.com>. He's a reputated dealer for Cosina.

He might have all the answers to your questions.

Good luck.
alfred

 

[Kev T]

Is it really?

C/V's website mentions that the SL75mm f2.5 Heliar is discontinued, but makes no mention of discontinuing the 125mm f2.5 Apo-Lanthar... When was this? Thanks in advance if you can provide a link...

Although this doesn't change my interest in acquiring this lens, unless they're all sold out!

Kev

 

[alfcnka]

There is no link. Heard from dealers most Voigtlander SL lens are discontinued.
Cosina is now busy with the Zeiss Ikon. You can also ask KhoKing (japan) or Joseph (HK) to check for stocks and prices.

It's a more suitable lens for MACRO rather than portraiture. Compare to a Nikon AFD105 the Voigt. focusing is slower. Meaning you make more focusing turns. Not sure if it's due to the 125mm focal length and bigger diameter. But this provides more precision focusing for Macro. Couple with TC14A, you get a 175mm F3.5. Great for butterflies and narrow depth of field shots.

The only plastics i find is the aperature ring and back lens cap. Even front lens cap is the screw-on metal.

The Voigt. has 9 aperature blades (rounder) whereas Nikon has only 8.

Overall, it's a much robust and rigid lens than Nikon.