Sigma 4/3 Compatible Products

nt means no text.

Some people are so irrational and emotionally tied to their viewpoints and beliefs that common sense cannot hope to prevail upon them. You are obviously such a person. So, yes, I have given up trying to persuade YOU, and I am quite confident that anyone who's thoughtful and can think logically has already seen enough evidence to understand just what is going on.

I don't know it for sure, and I can't cite any reliable source, but it is entirely logical that it would be - given that it is heavier than recent designs from Canon and Nikon. Of course, John Cozjin and cyainparadise assure us that ALL Olympus Digital Zuiko lenses (As well as all 4/3 Sigmas) have been designed from the ground up to only support the smaller image circle, so this MUST not be the case, given their clear expertise on this issue.

PeaceFrog said:

I don’t know if this is true or not but I remember reading somewhere
that the DZ 300 is actually the same optical design as an older film
model. Does anyone here know if that is true or not??? If you do
know, can you provide any links?

Thanks,

Greg

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Hi Greg,

As far as I'm aware that is false. The closest OM mount lens would be the Zuiko 350/2.8. The Zuiko Digital is of course 300mm and contains an extra 4 elements.

Bruce

All that we know is that it's not an older design that was actually produced for the OM product line.

DougJGreen said:

I don't know it for sure, and I can't cite any reliable source, but ...

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No comment required.

Well, I suppose that it could have been designed by a gaggle of Lepricons as well.

I'm sorry...but the conjecture in this thread is really starting to get out of hand.

Bruce

John Cozijn said:

No comment required.

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If only.

Unlike the issue we've been hashing around here ad nauseum, there isn't any compelling evidence on THIS one, JUST rumor. The disagreement we've had here is that you continue to ignore a mountain of circumstantial evidence with respect to Sigma's 4/3 lenses - and the Olympus lenses which are exact optical copies thereof, have NOT been designed specifically for the 4/3 image circle. Which, BTW, is not any big deal, because in many cases, especially with respect to telephotos, there is no substantial benefit to designing specifically to the 4/3 image circle, Olympus marketing hype notwithstanding.

Whether it was an older design or not. The fact is, there is no substantive benefit to designing a 300mm f2.8 lens specifically to the 4/3 image circle. This lens actually proves this point either way:

1) If it WAS designed to the 4/3 image circle, why, then is it heavier, and not any better than the similar 300mm f2.8 lenses from Canon and Nikon which are the mainstay of professional sports shooters worldwide?

2) If it WASN'T designed from the ground up for the 4/3 image circle, why WASN'T it? The only rational conclusion to draw would be that Olympus did a cost/benefit analysis and concluded that it was not worth doing such a new design for negligible benefit.

Despite your belligerent postings, I do actually read and consider what you and others say, and weigh it against whatever evidence is available.

As I have said several times, I think it likely on the balance of probabilities that the ZD 18-200 and 70-300 are optically licensed designs from Sigma, separately manufactured with some minimal mods (eg baffling). Unproveable, but likely, in the case of these are cheap consumer zooms.

However, this does not give warrant for the flood of baseless speculation, based on unsourced rumours, whether it be about the 14-45 kit zoom or the 300 super pro prime.

Nor does it give weight to windy generalisations about the (lack of) advantages accruing from lenses that are specifically designed for 4/3 format.

As for legacy glass, though there are many fine old optics that will yield a creditable result in theory, in practice things are not so simple. I don't know what kind of photography you do, but for my part I find such glass only operates well within restricted conditions on a 4/3 body, of which macro is probably a key example. This is not based on any preconceived principle, but the actual practice of trying to take interesting pictures in a variety of circumstances. Flaring, CA, backfocus, colour shifts, etc, occur all too frequently unless one is vigilant, in my experience.

Finally, as far as the OP's original issue is concerned, we do not know what Sigma's actual policy is in relation to releasing lenses for 4/3 eg the 70mm macro. These are matters of opinion that are in any case irrelevant, since I have no doubt Sigma will do whatever they believe to be in their own best commercial interests, whatever speculation swirls around forums such as this.
--
John
http://www.flickr.com/photos/cozijn/

John Cozijn said:

Despite your belligerent postings, I do actually read and consider
what you and others say, and weigh it against whatever evidence is
available.

As I have said several times, I think it likely on the balance of
probabilities that the ZD 18-200 and 70-300 are optically licensed
designs from Sigma, separately manufactured with some minimal mods
(eg baffling). Unproveable, but likely, in the case of these are
cheap consumer zooms.

Click to expand...

But that certainly WOULD establish the utter baselessness of your claim that ALL 4/3 lenses from both Sigma and Olympus, have been designed from the ground up for the 4/3 image circle.

John Cozijn said:

However, this does not give warrant for the flood of baseless
speculation, based on unsourced rumours, whether it be about the
14-45 kit zoom or the 300 super pro prime.

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I acknowledged that those were rumors, without enough evidence to draw any meaningful conclusions in these cases. I also established that the 300mm lens tends to support my argument irrespective of whether it is a new (but no better than Nikon or Canon's 35mm frame lenses) design, or an older one.

John Cozijn said:

Nor does it give weight to windy generalisations about the (lack of)
advantages accruing from lenses that are specifically designed for
4/3 format.

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Actually, in this case, it most assuredly does. Because the same sources you used to justify this position, you also used to argue that ALL 4/3 lenses from Olympus were optimally designed from the ground up for the 4/3 image circle. Discrediting one of the arguments as fictitious nonsense tends to discredit all of them.

John Cozijn said:

As for legacy glass, though there are many fine old optics that will
yield a creditable result in theory, in practice things are not so
simple. I don't know what kind of photography you do, but for my part
I find such glass only operates well within restricted conditions on
a 4/3 body, of which macro is probably a key example. This is not
based on any preconceived principle, but the actual practice of
trying to take interesting pictures in a variety of circumstances.
Flaring, CA, backfocus, colour shifts, etc, occur all too frequently
unless one is vigilant, in my experience.

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If by this you mean, deliberately, with cumbersome manual focus, and with metering in a limited fashion, I agree. But OPTICALLY, in terms purely of image quality, the better older lenses suffer from none of the limitations you ascribe to them.

John Cozijn said:

Finally, as far as the OP's original issue is concerned, we do not
know what Sigma's actual policy is in relation to releasing lenses
for 4/3 eg the 70mm macro. These are matters of opinion that are in
any case irrelevant, since I have no doubt Sigma will do whatever
they believe to be in their own best commercial interests, whatever
speculation swirls around forums such as this.

Click to expand...

I acknowledged that my opinion on this point was nothing more than an opinion. And we'll simply leave it at that.

John Cozijn said:

--
John
http://www.flickr.com/photos/cozijn/

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I know this discussion has moved into more lens related, but I am still disappointed that Sigma has not released a Olympus version of there ring flash.

Yes, Olympus makes one and its very nice...but if you ask me its crippled. First of all it will not work with my sigma 105mm unless I go out and make a adapter myself. If you own the 50mm Macro ZD lens you can either make your own adapter or spend $100 on the one that Olympus just happens to have. Its bad enough that you are going to shell out $500+ for the flash only to get it and find out that you need to shell out another $100 just to get the thing to work with your lens.

I love my Olympus system, but I still get ticked off when I see stuff like this. Yes its out of Olympus's control (that we know of) that no other people are making dedicated Ring flashes, but in the meantime why make your customers pay extra for a adapter to get a Flash working for there own lenses? Am I wrong to think that this flash was build to work with the 50mm Macro lens? You can't tell me that Olympus built this flash exclusively for the 35mm macro lens? Lets see high end flash build for low end macro lens....nope doesn't register here on the "makes sense" scale.

rant off

I'll let the rest stand.

But the issue of legacy glass is worthy of further exploration.

DougJGreen said:

If by this you mean, deliberately, with cumbersome manual focus, and
with metering in a limited fashion, I agree. But OPTICALLY, in terms
purely of image quality, the better older lenses suffer from none of
the limitations you ascribe to them.

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I did mean optically but it is often difficult to disentangle this from handling problems. You might find this interesting, from a knowledgeable and diligent poster on this forum:
http://www.jayandwanda.com/photography/lenscompare/ManLensShootout.html

The lenses compared are a 40mm f/1.8 Hexanon "pancake" (modified Hexanon mountP), a 50mm f/1.4 Takumar (M42 mount), a 135mm f/3.5 Soligor (T mount), a Vivitar Series 1 70-210 f/3.5 (first version make by Kino Optics - M42 mount), and a 50-300mm f/4.5 ED Nikkor (converted to a T mount).

My own experience is largely limited to OMZ lenses (as I mentioned earlier), and while not engaging in controlled tests, I have shot a lot of images. And I would say that it is prudent to be respectful of the limitations, which of course vary from lens to lens, particularly when pointing them at scenes that are not evenly illuminated. The optical problems I mentioned are real, as are the limits they impose on the real-world use of such glass.

You could perhaps be a little less categorical in your dismissal of other people's views.
--
John
http://www.flickr.com/photos/cozijn/

Are you talking to yourself? Afterall, you're the one who makes a statement and then when called on its validity, and even shown evdence that it is wrong, refuses to accept the fact that you were wrong.

The fact that you brought up two zooms that, while quite good in their day, are over 30 year old designs, is hardly convincing. No area of optical design has made more leaps and bounds in the past 20 years as zooms have. I've already said as much. Any good full 35mm frame zooms of today would blow those older zooms away, just as the digital zuikos do. The primes are much more relevant comparisons, because little has changed in the design of primes in that time, other than the advent of extremely fast ones using aspherical elements.

My point has always been that there aren't any inherent advantages in designing telephotos for a 4/3 image circle than for a larger 35mm frame or APS frame. If you'd stop obscuring this single issue with older lenses that have been outclassed by more recent full 35mm frame lens designs, I might give more credence to the rest of your post.

Please read the statement at Sigma's website.

The Macro 70mm F2.8 AF EX DG - Doesn't DG stand for Digital?

Direct quote from Sigma:

"This medium telephoto macro lens is ideal for both digital SLR cameras and 35mm film SLR cameras. The 70mm focal length gives an equivalent field of view as our popular 105mm macro lens when used on digital SLR cameras with an APS-C size image sensor."

Doesn't that IMPLY that the full image circle for 35mm film cameras is also being used for APS-C sized digital cameras? So why can't it be used for 4/3?

It would make perfect marketing sense for Sigma and Olympus at this point in time to conclude that it is imprudent to compete against each others' products because of the realtively small market for Fourthirds camera owners. I hope that the E-410/510 sales will expand this market significantly to support the existance of both Olympus and Sigma products.

--
Trevor

--
Trevor

DougJGreen said:

The FACT is, Olympus' 300mm f2.8 lens which covers the smaller 4/3
image circle, is actually bigger and heavier than the Nikon and Canon
300mm f2.8 lenses, which cover not just the APS frame, but the full
35mm frame. And both the Nikon and Canon lenses include Image
Stabilization built into them, yet they each weigh UNDER 3 Kg, while
the Olympus lens weighs 3.3 Kg.

As for how much glass is in these lenses? Well, the Nikon has fewer
elements as well 11, compared to 13 for the Olympus. The Canon has
more, 17, but the extra elements are small and light ones located at
the back of the lens, and the Olympus has more large elements up
front, which is why it weighs more than both the Nikon and Canon
lenses

Click to expand...

OM Zuiko 350mm f2.8 here:
http://zuserver2.star.ucl.ac.uk/~rwesson/eSIF/om-sif/lensgroup/350mmf28.htm

Zuiko Digital 300mm f2.8 here:

http://www.olympusamerica.com/cpg_section/lens/dea/products/lens/300_28/index.asp

By examining the optical formula and the specifications, it appears the new ZD has very similar dimensions to the old OMZ 350. The new ZD is longer by 5mm which would be more or less absorbed by the OM-4/3 adapter. The optical formulae have a close resemblance. One large element was added to the front - that accounts for the extra weight. Three elements were added to the rear and appear to act as a negative teleconverter - to convert 350mm to 300mm. This would converge the light rays to a smaller image circle and increase resolution slightly.

This would support DougGreen's assumptions that a quick and economical fix was in order and not spend a lot of R&D for a totally new design, because if they did a more compact and lighter solution would have resulted. Given the limited number of lenses they expect to sell, this approach is in agreement with the Accounting departments' constraints. Also, having an angle of view equivalent to 600mm, this behemoth of a 300 is compact compared to a 600mm lens.

Given the 20+ years gap in production and available optical glass, it would not be surprising to see some minor differences in the design. Lead base glass is no longer available and have to be substituted with Zinc or other other more environmentally friendly elements.

--
Trevor

such issues publicly?

cyainparadise said:

I agree with you. I'd like to see what proof Doug has of his claim.
Too many posters make statements that are not backed-up by fact. The
poster has no connection to any company, nor do they have any
expertise other than being interested in photography.

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By examining the optical formulae and having some knowledge of lens design, it is not hard to see that they are the same. For marketing reasons, neither party would publicly admit to "rebadging." Just compare Quantary lenses to Sigma.

Rebadging is nothing new. I have mentioned in previous posts that this has been done since the 1980s. Not so much with Sigma, but Tokina and Tamron zoom designs were used frequently by Canon, Olympus and Nikon.

They are also not copies as it would cost Olympus too much to duplicate the manufacturing facilities. In some cases, Tokina manufactured the lenes for the camera companies to their specifications (external appearances). Sometimes the lens coatings were tailored to the camera company's requirements.

In other cases, Tamron would supply the optical glass components and zoom cams and Nikon would manufacture their own housings, mounts and circuitry to maintain secrecy of their proprietory electronics. There are economies of scale too as Nikon manufactures lens mounts and aperture rings of the same design for all their lenses and cheaper to use their own parts for assembly. It would not make sense for Tamron to set up manufacturing of Nikon's aperture rings, zoom and focus ring rubber sleeves.

Country of manufacture is no indication of where the parts originated. Some components, are shipped to the China plant for final assembly and it is the place of final assembly that determines what is on the "MADE IN XXX" label. That is part of the import and export politics and quotas.

For those of you who firmly believe that each camera manufacturer makes every item and component themselves, you must have a sense of insecurity that obstructs your acceptance of how design and manufacturing business is conducted. Not only with cameras but all consumer products.

--
Trevor