Leica T performs digital lens correction , a claim by dpreview.com

[luigi bertolotti]

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I'm a relative neophyte here. I came on the forum just as the Leica X was coming out.

 

I just don't understand why people who have no interest in the camera seem to feel they need to denigrate people who do have an interest in the camera. I realize this thread is about some hearsay that has been blown up by DP Review, etc, but it hasn't taken this thread long to degenerate into finding the company guilty "as charged", as well as anyone who has an interest in trying out the T.

 

What's the big deal about letting people enjoy their choices without disparaging them as though they're inept and incompetent as well as "of course" rich?

 

OK, back to optics.

 

I think that indeed, in general terms, all the people that posted in this thread HAVE some interest towards the T... and imho (thinking at other "heated" threads) the level of "degeneration" is not so high...

[pico]

This thread is providing Leica's very smart market researchers with priceless metrics.

 

Do not not cease your impressions.

 

Those upset with the T, get a tin-foil hat.

 

 

 

 

 

Sent from my Etcha-sketch.

[IkarusJohn]

Just to get this discussion back into perspective, here is the DPReview Summary (again):

 

Our quick tests looking at the T's DNG files converted through DCRaw (via RawTherapee) show that Leica is in fact employing a thoroughly up-to-date lens design philosophy, similar to that used by pretty much every other mirrorless system. So the 18-56mm lens isn't fully corrected for distortion optically, but instead integrates software correction into the overall system design. This may not please purists, but frankly it counts as standard practice with modern lenses, and in our experience has little, if any, negative impact on the final image compared to fully-optical correction.

 

When it comes to lateral chromatic aberration, the lens is at least as well-corrected optically as we'd expect for a small zoom, and in fact probably better than most. But Leica is also taking the opportunity to reduce the visibility of color fringing via software correction. Again, this is simply standard practice in modern camera systems.

 

We're less certain about vignetting, but on the balance of probabilities would suggest that Leica is also reducing lens shading in software. We're less keen on this, and generally prefer it to be left to the user's discretion. But again, other mirrorless systems do the same thing (from, for example, Fujifilm and Sony).

 

Overall, we have no problem with Leica using this technology - incorporating software corrections into lens designs has enabled the creation of a range of very good lenses that wouldn't have been feasible if only glass were used. The only thing that we'd take issue with is the company claiming not to use this approach, when it so clearly is.

 

I don't see a problem. If you don't like the corrections, you have a DNG file which you can play with to your heart's desire. Leica claiming that the M8 & M9 were "camera's for life" annoyed me more.

 

Cheers

John

[CaptZoom]

Thanks for posting the bit from DPR,[mention=2688408]IkarusJohn[/mention].

[40mm f/2]

In my opinion digital lens correction is not just an easy fix but has a significant negative impact on picture quality.

correction of vignetting leads to the reduction of dynamic range in the corrected areas

correction of distortion leads to a reduced image seize (obvious in the DPreview article)

correction of chromatic aberrations leads to reduced resolution.

The more corrections have to be performed the more the impact. Physics can not be replaced by software. Small corrections on a optically well corrected lens can be quite positive for the final IQ.

I am disappointed by this trend. Sony's RX1 was supposed to have the perfect Zeiss lens and now Leica. At least M lenses are still designed to also work with film - so they must perform to a large degree without correction.

[Rick]

This may well be a very good camera but it is being promoted and marketed with all kinds of over the top fluff. I certainly would not be surprised if that was the impression Leica communicated to a number of people when they gave them early samples of the camera. Some of their other statements written on the T's product page are worse.

 

I get all of that. And, I get what you are saying. But, let Leica have their day. A group of very few people, made a very nice camera, that may not include a bleeding edge of technology sensor... but, they put forth a new Leica system camera, with what I'm sure will be some killer lenses, into a market of cropped sensor cameras. And, I believe they did a great job of giving those that want a premium cropped sensor product, with what will surely be great optics and image quality, another option, in a sea of plastic.

[AlanG]

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another option, in a sea of plastic.

 

Hmm...

[Rick]

Hmm...

 

A sea of plastic. Hmm, yes. The value will be in that sea. But, there are some folks that enjoy other virtues Leica will offer in this product and it will be a mix of performance and desire. But, so what, most of us are just punters that enjoy photography and part of that enjoyment is the equipment. If, it were not, all of the magazines, forums, and posts would not exist.

[diogenis]

In my opinion digital lens correction is not just an easy fix but has a significant negative impact on picture quality.

correction of vignetting leads to the reduction of dynamic range in the corrected areas

correction of distortion leads to a reduced image seize (obvious in the DPreview article)

correction of chromatic aberrations leads to reduced resolution.

The more corrections have to be performed the more the impact. Physics can not be replaced by software. Small corrections on a optically well corrected lens can be quite positive for the final IQ.

I am disappointed by this trend. Sony's RX1 was supposed to have the perfect Zeiss lens and now Leica. At least M lenses are still designed to also work with film - so they must perform to a large degree without correction.

 

 

Physics don't apply to film?

[imants]

LCD and sunlight don't mix no matter how many tap screen apps appear external VFs corrupt design

[jaapv]

In my opinion digital lens correction is not just an easy fix but has a significant negative impact on picture quality.

correction of vignetting leads to the reduction of dynamic range in the corrected areas

correction of distortion leads to a reduced image seize (obvious in the DPreview article)

correction of chromatic aberrations leads to reduced resolution.

The more corrections have to be performed the more the impact. Physics can not be replaced by software. Small corrections on a optically well corrected lens can be quite positive for the final IQ.

I am disappointed by this trend. Sony's RX1 was supposed to have the perfect Zeiss lens and now Leica. At least M lenses are still designed to also work with film - so they must perform to a large degree without correction.

Do you really think optical corrections come without tradeoffs?

[earleygallery]

Yes, I think you have been mistaken. I think there's been a fetishisation of optical quality over photographic opportunity by many Leica users, which I admit Leica have been happy to exploit, but which I've always regretted.

 

Peter, I usually agree with most of what you say on the forum but I'm honestly quite taken aback by the apparently sudden acceptance of poor optical performance from a Leica lens, from many here. It's like we've all been in some parallel universe all these years.

 

I also agree with AlanG that distortion in a wide lens is often a feature, and I think that to correct it as a matter of course is taking something away creatively from the photographer - M users don't benefit from such optical corrections unless they specifically choose to do so.

 

Then I go back to a previous point I made about the fact that an 18mm T lens isn't 18mm if something like 10-20% of the image is lost via correction for distortion.

 

Correction of CA or vignetting is less of an issue and indeed was essential to make the digital M work in the first place, but there was never any suggestion that M lenses needed correction for excessive optical distortion.

 

I take the point that the T has been designed this way from the 'ground up' as it were, and I also realise that the vast majority who buy a T and pack zoom won't know any different, they just want a simple to use better quality camera.

 

But that brings me back around to my real problem with this - the 'happy snapper' luxury camera buyer is choosing a Leica T because they think that they can take for granted the fact that it's going to be the best. I've often heard salespeople in stores say that Leica make the best lenses.

 

Going back to the Rolex analogy it would be a bit like someone buying a Rolex divers watch and then finding out that it shouldn't be worn if it's raining outside, but hey what does it matter because most people who buy them never go diving anyway and it looks the same.

 

For those who prefer car analogies, it's the Porsche Cayenne that turns out to be 2WD only and is crap on anything tougher than a grass verge in suburbia. Again most people buy them for the look, not to actually go off road just to look cool.

 

If Rolex and Porsche stopped making products that were 'the best' in this way I doubt they would have the same appeal.

 

Leica will get away with this one, certainly. I know the typical T user won't know or care. But I doubt that those who are defending the use of digital correction now will be quite so accepting of such sub-standard M lenses.

[farnz]

... but there was never any suggestion that M lenses needed correction for excessive optical distortion. ....

(Not trying to start an argument with you, James, just borrowing some of your text.)

 

Wide angle M lenses are deliberately designed to be rectilinear so they're accordingly optically corrected to produce straight vertical lines when level (point them up and down and of course you'll get keystoning). The smaller a lens the exponentially harder it is to correct for distortion and it seems to me from the pictures posted earlier in this thread that T lenses are curvilinear, not rectilinear, because the verticals are curved. It seems feasible to me that the constrictions of size may prevent wide angle T lenses from being rectilinear, hence the uncorrected optical distortion that is evident, and there would be no option than to correct the distortion using software.

 

The proof of the pudding is whether any of the other manufacturers' lenses of the same size as T lenses are able to produce true rectilinear wide angle lenses. I'm not aware of any so can any of the opponents of software correction point to any that are? If not, then Leica's in the same boat as everybody else and the boundaries of physics are the limiting factor rather than Leica supposedly selling poorly designed lenses at high prices (as appears to be a charge levied in this thread).

 

Pete.

[jaapv]

But - the penalty is that on most M wideangles - including the Summilux 35 FLE- the plane of focus is far from flat as a result of the correction of spherical aberration. We had a few spirited threads on the subject. .

 

Now if one would flatten the plane of focus which would be a very desirable correction the result would most likely be geometrical distortion. Which, if corrected digitally, would result in an even better lens overall.

Digital correction is NOT a cover-up tool for bad design, it is an extra tool for the optical designer to get even better performance.

[pgk]

,,,,,Leica supposedly selling poorly designed lenses at high prices (as appears to be a charge levied in this thread).

And here was me thinking that the charges were:

Lying over software implementation (circumstantial evidence and unproven),

Poor advertising practices by over exaggerating the ancestry and optics of the T (matter of opinion but most advertising is about stating a product to be the 'best' to but isn't it? Or are we naive enough to accept advertising prattle with no questions?),

Passing off a mediocre lens as being stellar (still mainly conjecture at this point I would say) in order to profiteer, and

Probably more if I could be bothered.

But my real problem here is that if anyone thinks that Leica is going to increase its market share by producing the 'same old' (albeit superb;)) equipment and lenses, then they are wrong, they are not. And trying to compete against much larger manufacturers on price would be a tall order. So how exactly can they compete. Design!

 

Many cameras produce results way beyond the needs of their users already. Building one which does so and is well designed is obviously a solution. That it may also be an enthusiasts camera remains to be seen, but my guess is that it will find a niche and settle into it well.

 

FWIW I was talking to someone into photography the other day; never heard of Leica. Depending on a historic reputation is no longer sufficient to propel Leica forward IMHO. So there you have it. Come up with a better strategy and I will be interested to hear it (perhaps Leica will too:eek:), but suggesting that Leica remain optical purists, produce a compact interchangeable lens camera which is substantially better than anything else on the market (and many are already very good), is simply not going to happen.

[wattsy]

Which, if corrected digitally, would result in an even better lens overall.

Digital correction is NOT a cover-up tool for bad design, it is an extra tool for the optical designer to get even better performance.

 

I don't wish to wade into the debate about the merits or otherwise of this approach to lens design – I really don't care either way, the T system is not for me – but I'm surprised at how you are spinning this, Jaap, because I'm not sure how consistent it is with some of the things you have written before. In fact, this lens design philosophy is just the kind of thing that I think you would have criticised other manufacturers for, along with the notion of "kit zoom" lenses, crop-framed sensors, CMOS (before the advent of the M240), EVF only (ditto), etc.

 

As a side note, does anyone know how the S lenses perform without in-camera digital corrections? There was a time when Hasselblad was widely lambasted by, amongst others, people in this forum for adopting this approach when it released its 28mm H lens.

[AlanG]

Since so many Leica buyers are fixated on lens quality, maybe each purchase should come with an intro course in lens design.

 

As for the T system in general... Leica finally produced a camera that has all of the design elements that Leica forum members have been clamoring for,

[pico]

Reading this thread made me search for a respite and Lake Wobegon immediately came to mind. Lake Wobegon where "all the women are strong, all the men are good looking, and all the children are above average", obviously an impossible demographic.

 

Then I thought of Ralph's Pretty Good Grocery store where if you can't find what you want, you probably can get along pretty good without it. We have just such a store here in town called The Co-operative which has an elitist, spendy, but selective inventory; while you won't starve living on just what they offer, you will be poorer for it. Their customers represent everything but the middle. It's lawyers, doctors, academics and young socialist hippies.

 

The irony is enough to keep me in good humor. So is Leica. I can rent a part of the store to sell cameras. I think that Holga has a greater profit margin than Leica and might just tip the books enough to make it a viable business. Pico's Pretty Good Camera Store - the place that obviates the middle.

 

Now for the first coffee of the morning.

[jaapv]

I don't wish to wade into the debate about the merits or otherwise of this approach to lens design – I really don't care either way, the T system is not for me – but I'm surprised at how you are spinning this, Jaap, because I'm not sure how consistent it is with some of the things you have written before. In fact, this lens design philosophy is just the kind of thing that I think you would have criticised other manufacturers for, along with the notion of "kit zoom" lenses, crop-framed sensors, CMOS (before the advent of the M240), EVF only (ditto), etc.

 

As a side note, does anyone know how the S lenses perform without in-camera digital corrections? There was a time when Hasselblad was widely lambasted by, amongst others, people in this forum for adopting this approach when it released its 28mm H lens.

I've never criticized cropped sensors, kit lenses or CMos... However, I have little patience with criticism based on misconceptions.

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Hallo,

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[tomasis7]

a sea of plastic.

 

So Leica is one of most environment friendly companies?

 

Not many can afford a hundred products from them therefore less waste and gas syndrome. :D

 

Less is more.