Lives in Norway Oslo, Norway
Works as a Statistician
Joined on May 9, 2009


Total: 16, showing: 1 – 16

Of course this is very much about Huawei buying the right to decorate their flagship models with the Leica badge. But there may be quite a bit more to it, for neither seems to have a very strong position in the actual product segment - Huawei needs to be there, and for Leica it could be quite lucrative to be there. So why not go there together?

Link | Posted on Feb 27, 2016 at 10:07 UTC as 10th comment | 2 replies

I don't think many who question the practicality of this lens have really used the 50-150(135) lenses in the field. I have, both Sigma's major versions, and I would gladly give up the last 50mm in exchange for 4/3 stop. In practice, I often prefer to use the 85/1.G @f/2.2-2.5 and crop instead of dragging the 50-150 OS. But that's not a very good solution, and I would like to be able to go wider and faster.
Because of cropping, the reach isn't that much of a problem with a well performing lens and moderate ISO settings.
With this lens, the new Tokina 14-20/2 and the 18-35A, we have a fairly complete set of primes for crop. On FF, that would be 21, 24, 28, 35, 50, 60, 85, 105, 135 and 150mm. Of course that set gives a lot more than the three bags of primes (including the use on crop bodies), but it is a toolkit.

Link | Posted on Feb 20, 2016 at 14:28 UTC as 24th comment
In reply to:

noflashplease: Why buy an expensive crop circle lens in an era when the industry is shifting away from APS-C back to full frame? Even Pentax has a full frame body.

Sigma didn't hit it with their 50-150 releases: The first ones only kept up to about 135mm, the last one became large and heavy (and not inexpesive) as a 70-200. When they couldn't compensate for the f-stop "lost" on crop, they could never be great successes. This 50-100A has a completely different potential in the toolkit. It goes very well together with universal zooms like the 16-80/2.8-4 Nikkor - with more than 2 stops advantage in the overlapping range: Typically something to reach for when the standard zoom gets too slow.
If it has similar performance to the 18-35A, you gain, effectively about 2/3 stops relative to the inexpensive (ca f/2) native primes, and one of the fast native primes is likely to cost more than this zoom. Furthermore, their performance on the crop sensor is by no means guaranteed.
Also, shooting at lower ISO may allow for more cropping.

Link | Posted on Feb 20, 2016 at 13:52 UTC
In reply to:

TTLstalker: I don't see this as so great. A 70 F1.4 would have been good enough. or if a zoom, I would rather have moderate wide angle to a short telephoto , like 18 -50 F2

Sigma has positioned their crop zooms leaving room for a future 24-55/1.8 model. And the three makes space for FF variants with shorter ranges. We already got the 24-35/2 from the 18-35 basic design, we may get something like 90-135/2 from the 50-100 and, eventually, something like a 45-70 from a 24-55.

Link | Posted on Feb 20, 2016 at 13:22 UTC
In reply to:

MattSolo: They should've offered this for FF. Could've been a hell of a lens. 100 1.8 I want that.

Commenting on FastGlassLover and the replies: I don't think many have really tried some of the best old, fast glass. I think the 105/1.8 AIS Nikkor is a classic, and the only major weakness I see in my copy, is the rather weak performance at f/1.8-2.2. It was very good on the D300, seems to need a bit more stopping down on the D7100. That's where something like the 50-100A comes in handy.

Link | Posted on Feb 20, 2016 at 13:02 UTC

I think it would help a lot it the manufacturers published the "within specs" areas in their MTF charts. For now 10&30 lp/mm would suffice for FF and APS-C. That would tell me, as a buyer, much more than any singular measure of variability, and I could make an informed choice instead of looking at the theoretical curves and a bunch of test results and try to figure out approximately what I may expect.
The article should be compulsory stuff for people discussing lens quality, IMHO.

Link | Posted on Feb 13, 2016 at 12:33 UTC as 8th comment
In reply to:

Frank_BR: Roger Cicala's article is interesting, but it reflects his particular view of the manufacture of lenses. An optical MTF bench is not an appropriate tool for mass production of lens. A computerized test (like Imatest) is perfectly suitable to verify if a lens that just rolls off the production line is within specifications. By the way, computerized lens tests measure MTF, don't they?

(it continues...)

IMHO, relative to the price, kit lenses are for DSLR and mirrorless are "high quality mass produced stuff". "High quality" is no absolute standard, and the challenges come with requirements to stay, for example, within 15% (relatively) of the lens' computed MTF. To meet this kind of requirement without considerable extra costs, the construction and manufacturing process must be designed for it.

Link | Posted on Feb 13, 2016 at 12:20 UTC
In reply to:

Horshack: Roger dutifully sheds light on a surprisingly complex issue. But let's not throw the baby out with the bathwater when it comes to forgiving the QC sins of these companies on the altar of complexity and perceived manufacturing/testing cost. The fact is we don't have enough information to quantify and project how QC could improve relative to the additional marginal costs of those improvements. But in the absence of such information (which could be used to either forgive or indict their QC sins), I think it's useful to look at one essential clue - how is it that these companies have such meager manufacturing+service testing capabilities for what are precision, high-value products? Is it really due to the cost of such equipment and the personnel needed to operate them? Or is it instead a 'see no evil do no evil' scenario, where plausible deniability is utilized to mask a simple unwillingness to deliver a consistent quality product irrespective of how small the impact on margins may be.

I think it is a valid question, but to me, the all-important thing is: They get away with it. If they don't, they will have to improve, if they do - well just look at the situation now.

Link | Posted on Feb 13, 2016 at 12:09 UTC
In reply to:

Mike FL: So, basically the message of this article tried to deliver by LensRentals is very clear:

If you want picture perfect, rent lens from my LensRentals b/c:
- I have $ XXX USD test bench for the lens
- Lens makers do not know what are they doing
- I can do it right, but too hard for Lens makers do it right.

Again, please rent the lens from me. Please.

Sorry for you Mike FL. You missed basically the whole content of a very interesting article that goes a long way towards explaining what many of of us experience.

Link | Posted on Feb 13, 2016 at 12:02 UTC
In reply to:

digilux: I used to work nightshifts at a Philips plant, doing quality control on laser units for Matchline color teevees (remember those?)...... the 'best' ones were going out for export to European countries like Germany Sweden etc, 2nd level for domestic use (Holland) and the rest went to Asia, Americas and the rest of the world....I couldn't believe it at first but I guess all major industries work like this!

I have been wondering if not at least Nikon does something similar at times. The Polish reviews so often (but far from always) get worse results for Nikon lenses than other, "western", review sites. I don't think lack of skills could fully explain it, and for Sigma, I haven't seen anything in that direction. And lensrentals have documented considerable variation in Nikon optics.
So, just maybe...?

Link | Posted on Feb 13, 2016 at 11:58 UTC
In reply to:

garyknrd: What a bunch of nonsense.

I can't see how this article smells.They use this for their own QA, and are able to offer better bang for the bucks, but so what? Their main perspecitve it the user's, IMHO:
"A couple of manufacturer’s have quite obviously started improving copy-to-copy variation already. At least one of them has started to use this very quietly in their marketing. I really hope that more of them are going to see the advantage in publishing something like our variation number, or even just a real-world resolution number that they guarantee their lenses will meet. Some manufacturer, someday, will realize the advantage of not having people question how much their lenses vary. Once one of them does this, maybe optical quality and consistency will become just as important a marketing tool as computer generated, little-to-do-with-the-copy-you-get MTF charts are now."

Link | Posted on Feb 13, 2016 at 11:50 UTC
In reply to:

c45: On different but related topic, according to many experts, the optical performance of modern lenses had deteriorated in many areas. Lens manufactures react to overwhelming pressure coming from digital-photography consumers (many of them just pixel peepers) to eliminate easily detectable chromatic aberration and deliver corner-to-corner sharpness. Both goals can accomplished at design level by adding optical lens-elements to the design, it's not uncommon now days to see 20+ glass elements in a lens. Unfortunately, adding glass element causes deterioration of micro-contrast, perceptual depth of field, color saturation etc.
And, unfortunately not all of it can be corrected in post processing.
Many photographers are buying older low glass element-count lenses (often manual focus ZEISSs, Nikons or Voighlanders) to get maximum IQ.

"All things being equal", a lens with more elements trivially will have less transmission and contrast than a lens with fewer, yes. But things are not equal, those extra elements are introduced precisely to reduce the problems of the simpler designs. Which is why it is hard to gett cheap, fast glass with good contrast fully open. Just try to find it :-)

Link | Posted on Feb 13, 2016 at 11:20 UTC
In reply to:

M1963: There's another factor that adds to the price of a lens. Certified QC systems complying to standards such as ISO (not the sensitivity value we're acquainted to) involve quality control procedures at every production stage, which forcefully means more human resources and documented procedures. It is no longer acceptable to have just one person sitting at the end of the production line verifying the products and gluing stickers with the word "passed" on them. That's archaic by today's standards.
Of course this adds to cost, but it can also bring considerable savings. It's cheaper when you detect a defective item at the beginning of the production line: you don't have to get rid of the final product altogether. The risk of defects is prevented more effectively this way. These quality assurance systems can be expensive to implement, but in the long term they pay off. Big time.

AiryDiscus clearly has a professional life, and he shares some of its content with us, for which we should be grateful.
I don't think it's too much to ask, that if you don't want to go into the evidence he presents, stay away from commenting on it. Not primarily for his sake, but for all of us who are interested in the subject matter and want to be spared of all this noise.

Link | Posted on Feb 13, 2016 at 11:08 UTC
In reply to:

Don Diafragma: WOW! Another Sony Story....

DPR says they are independent press, but sometimes I unfortunately get the feeling they are an extension of the Sony PR machine.

I would add one important reason for giving this lens release good coverage: Sony's system now emerges as a third alternative for commercial FF shooting, along with CaNikon. That is significant whether one is interested in that segment of gear or not. If not - just skip it.
I for one don't see much fanboyish attitude from DPR where it would really matter, e.g. the A7RII review.

Link | Posted on Feb 5, 2016 at 08:54 UTC

I think they are saying a lot between the lines here. It really reminds me of early 2007 Nikon statements - only they are way more honest now. One important reason Nikon won't talk about a roadmap is - there is none. And I would guess their shareholder relations makes it much more difficult for them to talk about strategy than e.g. Sigma.

The flat, and obviously wrong, denial of FX domination lens-wise may mean they may actually do something about it right now. And some glaring holes in the present lineup may be filled with new/updated FX glass, like 24/1.8, 135/1.8 and a new release of the 50/1.4 with better performance in the f/1.4-f/2.2 zone.

The obvious answer to the growing problem of AF precision is on-chip PDAF - that may also solve the problem of residual spherical aberration, which in many cases is considerable. The way they comment on Canon's top of the line AF systems, may be interpreted as "we won't go so far along that path".

Link | Posted on Apr 11, 2015 at 09:22 UTC as 88th comment | 1 reply
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