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Messages - elflord

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31
Third Party Manufacturers / Re: DxOMark trashes the Leica M9 sensor
« on: March 23, 2013, 01:13:12 PM »
Yes "Lenses are a different matter" but lenses are an important part of a DSLR, no lens, no photo! -- no one is disputing DxO being a leading tester of sensors, however real world photography requires lenses, but when a "leading tester" like DxO easily screws up on testing lenses,  I too wouldn't necessarily trust "the leading tester's opinion, especially when what I need is a Camera and a lens to take real world photos

On this we agree -- I don't give much weight to their opinions, but thankfully they do a good job at publishing their measurements which I can read and understand.

Your point that the sensor is merely part of the camera which is merely part of the camera system is understood and well taken. That is why we don't just have sensor benchmarks -- lens reviews (measurements and qualitative/subjective reviews) as well as reviews of the bodies themselves (both the dpreview approach and more subjective testing) all factor into appraising gear.

So I'm not trying to say that the sensor is everything, but I am pointing out that DxO do a pretty good job at benchmarking  sensor performance. I also find hard cold numbers to be a refreshing alternative to exaggerated claims from manufacturers, fans, or new users trying to justify their purchase after the fact (instead of doing due diligence before the fact).

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However, I do engage in arguments with people who keep insisting that everyone must accept the DxO test results as the absolute fact

Well, their measurements (unlike exaggerated claims from fans) are at least objective. You can argue about what the measurements mean (but even that requires some understanding, um,  of what the measurements mean)

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;D As I said before, a good image requires a camera and lens
this we agree on
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when companies like DxO or any other company gives out highly questionable test results, I do not necessarily refer to them as "objective".

I don't see how this is related to the first point. Regarding questionable test results, it's not at all clear that DxO's all-over-the-map lens numbers point to any bias (lots of variance but not much bias! but it does shed some light on why their lens tests don't have the same stature as their sensor benchmarks). It's like seeing a leading quarterback play a bad golf game and then wonder if they really are a good quarterback.  DxO's sensor benchmarks and methods have been studied and analyzed ad-nasueum and have stood up to scrutiny pretty well.

32
Lenses / Re: small primes to go with SL1?
« on: March 23, 2013, 12:55:16 PM »
I'm actually pretty excited about the announcement of the SL1. price-wise and function-wise it seems very competitive against m4/3 cameras which I've been considering for a while for a back-up/casual camera.

But that's why it's not really competitive against m4/3 cameras -- even with the reduced form factor, it still has the extra thickness because it's using a mount with a longer flange distance.

That said, Canon's wide non-L primes are pretty tiny (among Canon's smallest lenses) and optically quite decent (the 35mm f/2 and the 28mm f/2.8)

33
Reviews / Re: Most Objective and Less Objective REVIEWER?
« on: March 23, 2013, 08:40:24 AM »
So that pushed me to make this Poll, to see the users opinion and maybe the credibility of the reviewers.

Seems to me that many don't understand what "objective" means. "Objective" is not the same thing as "credible" or "useful". The luminous landscape reviews for example are largely subjective -- they generally do not contain any measurements or test chart shots, they are largely descriptions of the author's experience with and impressions of the lens.

Lens Rentals is a very useful site, and contains a large amount of both objective tests as well as purely subjective "Roger's take" comments. 

TDP have the test charts, but I don't see how that website has any business leading this poll. Objective doesn't mean "subjective and agrees with me". Ironically, the two highest scoring sites in the poll are two of the more subjective reviewers (e.g. lenstip and photozone are more objective than LR or TDP)

34
Third Party Manufacturers / Re: DxOMark trashes the Leica M9 sensor
« on: March 23, 2013, 08:15:44 AM »
+1  ... actually several people at nikonrumors echo similar sentiment, recently DxO ranked some Sigma and Tamron zoom lenses ahead of some of the better Nikon zoom lenses ...  also the Nikkor 70-200 f/4 scores higher than Nikkor 70-200 f/2.8  ... lot of the Nikon users are not very thrilled by it. I'm no expert at DxO scores but ranking Sigma 120-400 lens ahead of some of the Nikon lenses clearly shows that real world results and lab tested results are very different.

Lenses are a different matter -- DxO are the leading tester when it comes to sensors, but there are a number of sources who test lenses and appear to do a better job than DxO. Having said that, I wouldn't necessarily trust the popular opinion at a camera "rumors" site (which tend to be heavily stacked with "fans") over an objective reviewer.

35
Third Party Manufacturers / Re: DxOMark trashes the Leica M9 sensor
« on: March 23, 2013, 08:12:07 AM »
And I will reiterate again, that their ISO score is weighted toward the base ISO, and not at more moderate levels

Completely wrong, please review their method for ISO score. The dynamic range and color depth scores use base ISO. The ISO score is the highest ISO that meets a number of image quality criteria (the highest for which a certain noise level and dynamic range are maintained)
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And then there's the downsampling to 8 megapixels...certainly that helps the D800...a ton!  It's also a meaningless method of scoring noise.

Also not true. Normalizing to a common resolution is completely sensible unless you're always viewing 100% crops. The typical use case is to ultimately print images at the same size or otherwise rescale the image to the same size. To do otherwise is a "pixel peeping" approach. They have "screen DR" so that you can also see the per-pixel results, but these are not as meaningful.

 
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If it scores less than 10 points behind the D800E, then in reality, it's actually 10 points ahead..

I don't think so -- perhaps you can show us your industry leading benchmark that demonstrates this.

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.and why give the 800E one more point just for not having an anti aliasing filter?  The sensors are THE SAME... 

The anti-aliasing filter obviously has some impact on noise properties of the image. You wouldn't expect an enormous difference but then the test doesn't show an enormous distance so I don't really understand this complaint.

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If average people like me can predict the outcome of a test, 6 months or more before the product is even announced in the public domain, while it is still a rumor...then you have to admit, it does smack of favoritism and intentionally skewed test results.

Maybe it just means that average people can predict how well the next sensor from each major manufacturer will perform. Given the relatively slow trajectory in sensor improvements, today's performance is a pretty good predictor of tomorrow's performance.

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I mean, the little Nikon D5200 scores 2 points better than the 1Dx...GET F***ING REAL...

Canon's low ISO noise hurts them because the aggregate score is heavily weighted towards low ISO performance. The 1DX has substantially better high ISO performance but that is not the only factor the overall score takes into account. The 1DX also has a number of features that are important to serious photographers, but these don't enter into the test either.
 
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That's like saying a Prius scores higher than a Ferrari 458 because it gets better gas mileage,

Well, what do you mean by "scores higher" ? Trying to assign a single numerical "score" to something complex is always a difficult task. Here's one -- should a Mazda Miata score "better" or "worse" than a Honda accord ?

The reason they do report a single aggregate score is that many users do not want to dig deeper. But for those who are, they publish all the underlying measurements.

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or because the driver tends to obey the speed limit more closely.  The test is just wrong, skewed to portray a "truth" that is too narrow in its scope to have the meaning that many think it does.

The test is just fine. You are confusing the test with the score. You may disagree with the way the factors are aggregated, but they do provide their measurements for you so that you can get the most out of their tests even if you don't agree with the weighting scheme (or if you want to understand why the results came out the way they did).

The notion that the test is intentionally biased in favor of Nikon is just silly. DxO devised their test score and methods before Canons struggles with low ISO performance became the elephant in the room.

36
I am torn between keeping my sony nex 6 for the wife or getting her the new sl1 with a 40mm pancake. She just uses auto and wants to shove it in her purse just on occasional outings where lugging my 5d would be overkill. I think the sl1 is more versatile since all my lenses will serve a dual purpose and she like my 60d when I had it. She is just not the type to want larger heavy gear but I thought with either I could start to teach her how to use the pasm modes to control her photo's at times. Does anyone have an opinion? I just dont want to get her the eos if everyone thinks that its much larger and bulkier. I have noone else to ask.

micro 4/3 with a small prime (the Pany 20mm or 25mm). DSLR is a bit of an overkill for a purse. The new Olympus bodies have Sony sensors and the micro 4/3 mount has much better lens offerings.

37
You seem to have never encountered a person who wished for a simpler, smaller camera.

I've encountered both -- those who wish for small simple cameras and those who wish for small but powerful cameras. The former use iphones or point and shoots, the latter usually use SLRs or mirrorless.

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  Many people who buy low end DSLRS cameras love pictures but are not into nit-picking over technical adjustments, doing AFMA or reading about it on gear forums.  They buy zooms, not primes, because zooms are more useful to them. 

Yes, but many people who buy low end DSLRs are buying them because they can't afford the high end cameras (e.g. art or photography students).

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And your claim about treating buyers of low end products "with contempt" is imaginative, but not based on any fact.  It presumes a fantastic mind-reading ability.  You imagine this contempt for the buyer because your premise is that cheaper products should have the same advanced features as more expensive products, which is not a valid premise in the business world.  That's a prescription for business failure.

But what makes a product "cheap" or "expensive" ?

Feature bullet points, especially firmware related ones aren't it -- even point and shoots have impressive feature sets these days (face recognition, built in panorama support, as well as more "serious" features like raw support, color temperature control, spot metering, manual focus and/or selectable AF regions, hotshoe mounted flash etc)

In a competitive market, what makes a product expensive are features that add substantially to marginal or fixed costs of production, and/or absence of economy of scale to absorb fixed costs.  In the case of cameras, the former largely consists of the sensor (e.g. larger sensors are MUCH more expensive), and most probably a more rigorous testing process.

There's no reason features that don't add substantially to marginal cost of production shouldn't be included in cheaper products. Failing to put this there is just a way of crippling the cheaper products. In Canon's case, it seems to be a calculated move to prevent their low end products from cannibalizing sales from their flagships. Whether or not this will be a good business strategy for them is an empirical question -- but I would find it hard to recommend the rebel line to a serious user on a tight budget.

38
You completely misunderstood my point, which was that Rebel users are certainly not constantly sending their gear to Canon for autofocus micro-adjustments.  You think I'm saying something bad about them when I'm not.  I'm a parent at the soccer game too and I respect their situation.  They want good photos, and getting good photos of soccer (or basketball or many other sports) is not easy.  The Rebel is the camera they bought because they knew that a point & shoot wouldn't do the job as well. The Rebel does that job much better, whether it's a soccer game, a show at school, a birthday party, etc.

The first thing a photographer-parent does (as a parent) is likely to be "take baby photos" which again they often do with an inexpensive fast prime lens. They might not be up to the task of sending lenses back to Canon but they might be up to the task of reading a manual and adjusting lenses.

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You used the word "confusing" in quotes, but that's not the word I used.  If you could appreciate the perspective of many parents, you would recognize that too many unfamiliar features on a camera menu is a minus, not a plus. 

I don't buy this line of argument. Features that are commonly used can be made available with buttons and dials (without any menu browsing so they aren't buried in a decision tree). The less often used a feature is, the further down the choice heirarchy it can go (without cluttering the top level).

Rebel cameras already support a number of advanced features that these ignorant savages you speak of have little understanding of or use for, (one such example is a matrix interface for adjusting white balance -- oddly enough they don't have a simple color temperature).

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The thrust of the critics in this thread can be summarized as:  The new Rebel doesn't meet my personal needs! 

Actually, my argument is that the Rebel is simply not a very good choice for hobbyists on a budget because the manufacturer treats buyers of its low end products with contempt. Buyers at this price point are better served by other products (either used Canon from different product lines or other manufacturers)

39
So you know a lot of Rebel users constantly sending their gear to Canon for adjustments?  I don't.  But maybe I'll ask the other parents at the soccer game or at the school play.

If Canon share this attitude towards users of their entry level SLRs, that would certainly explain their policy of removing "confusing" features that "parents at the soccer game" don't understand.


40
Your missing the point.
Maybe it's because he doesn't have one.

He seems to be insisting that everyone use "dynamic range" to mean what he wants it to mean (which happens to be a useless definition as far as photography is concerned) as opposed to the useful (and correct) definition that DxO use.

What is the point of assigning as useless definition to the term "dynamic range" ? Or is there some deep significance to his definition of DR that I'm missing ?

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But, then again, you always have, so there isn't any surprise there.

Well, if you have any deep insight into this, please do share it with us. Simply asserting that you are more insightful (but aren't able to share your insights) might make you feel better, but it is not terribly persuasive.

41
This strikes me as a rather pointless (and ultimately futile) attempt to argue against using the commonly understood term ("dynamic range") for the quantity that really matters (saturation to noise floor).

He's not even correct -- DxO's usage is correct (the term "dynamic range" is quite often used both in digital photography and other domains to mean "saturation point to noise floor").

I don't really see the point of trying to diminish the importance of the dynamic range as measured by DxO by assigning to it a term that no-one is familiar with (aside from "advocating" for a particular brand whose sensors have weak dynamic range, that is)

42
Lenses / Re: Addicted to dof
« on: March 06, 2013, 06:04:44 AM »
Hi all.

I have the canon 50mm 1.4 an the canon 85mm 1.8 using on my 5d3.

I'm constantly on a quest for shallower dof. I do a lot of street photography.


My hesitations on upgrading to the L lenses are (other than cost):

Will I actually see a noticeable difference in dof?
The 50mmL has a pronounced focus shift narrower than f2.
The 85mm 1.2. is slower af than the 1.8

My question is will I see much difference between 1.4 and 1.2 @ 50mm and 1.8 and 1.2 at 85mm?
Also, does anyone know if the sigma 85 is any good? And similarly is it worth going from 85mm 1.8 to 85mm 1.4?

Yes, the Sigma is pretty good. Myself and several other forum members are satisfied owners. Take a look at the review on thedigitalpicture where it spanks the Zeiss and the Canon f/1.8 -- it's second in image quality (and a close second) only to the 85mm f/1.2. AF speed on the sigma is quite reasonable.

43
PowerShot / Re: P&S - Faster lens or bigger sensor?
« on: February 27, 2013, 06:46:18 PM »
Dear CR gurus,
Technical question: for P&S cameras, is it better to have a larger sensor or a faster lens?
Background: I want to buy a decent P&S for my wife, but I've seen that truly pocketable cameras have either faster lenses or bigger sensors, but not both at the same time; e.g., the Canon S110 has a somewhat larger sensor than most P&S and is really small, but the max aperture of its lens is only f/5.9 at the telephoto end. On the other hand, a soon-to-be-released Olympus ZX-10 has a faster lens (f/1.8-2.7), but a smaller sensor.
(I'll get myself a Fuji X20 or an Olympus ZX-2 for carrying around later on, but she prefers something even smaller and cheaper.)
Any thoughts on larger sensor vs faster lens?
Thanks in advance!
Daniel

The bigger sensor will perform better in favourable lighting (e.g. when you don't have to crank up the ISO). In less than ideal lighting, it's a wash (though again the difference in maximum aperture may be smaller at the wide end in which case the camera with the larger sensor may still do better)

44
Lenses / Re: Why aren't zoom lenses faster than 2.8?
« on: February 24, 2013, 08:28:40 AM »
Generally the technical difficulty of achieving a particular geometry is INDEPENDENT of sensor size, meaning it's equally difficult to create a 17-55mm f/2.8 IS lens as it is to create a 24-105mm f/4.0 IS.

How about a 25mm f/0.7 lens for micro 4/3 ? Should that be comparably difficult to design and build as a 50mm f/1.4 full frame lens ?

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To respond to your post though, there is NO benefit to a 1 stop faster aperture on APS-C sensor vs full frame because they (more than) cancel each other out. You don't stop action any quicker at all, whatsoever, because remember the ISO is skewed too, so all you're doing is just turning up the ISO sensitivity in a roundabout way. You have been misled into thinking there is a benefit.

The 400mm f/4 APS-C lens is "equivalent" to a 640mm f/6.4 lens. If you're distance limited, this really is preferable to a 400mm f/5.6 lens on full frame. You're right that it isn't "faster", but it is much longer than the 400mm f/5.6 full frame setup and almost as fast. Unfortunately, it's also quite a bit more expensive (not a whole lot cheaper to make the same lens for a smaller image circle)




45
Lenses / Re: Why aren't zoom lenses faster than 2.8?
« on: February 24, 2013, 08:12:22 AM »
As Radiating pointed out, these smaller sensors have their amplification turned up to make their ISO ratings match the apertures. ISO 1600 on a G15 at f2.8 and 1/100th of a sec will match ISO 1600 on a 5D3 at f2.8 and 1/100th of a sec for exposure. But I'm sure no-one here disputes the fact that the smaller G15 sensor will produce much more noise at the same ISO's. Its simply because the amplification is turned up much higher to compensate for the much smaller imaging circle projecting much less light onto the sensor.

The "amplification" is not "turned up" for the smaller sensor. A 6x4mm sensor is no more noisy (or "amplified") than a 6x4mm region of a 35mm sensor. Images from the smaller sensor are (theoretically) about as noisy as a crop from a larger sensor.

The reduction in noise has to do with sampling density and averaging, not amplification.

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