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Messages - neuroanatomist

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46
Third Party Manufacturers / Re: DXO uh-oh?
« on: July 27, 2014, 09:31:32 PM »
The margin of error in her D3s measurements were very small; she included them for completeness, and was open about not understanding their source. The variance was small enough to be immaterial to the results.

Sorry, but your statement does not align well with hers:

I re-tested both of my D3 bodies, plus the new D3s, for this - just to make sure I produced a valid comparison. For some obscure reason - sunspots or moon phase or other strangeness - photons are behaving better today, and I achieved higher FWC results for my D3's than I have before. Because of this discrepancy, I am only going to report relative performance between the D3s and D3, instead of giving absolute measurements.

She states the discrepancy was significant enough that she would not report the absolute values.  If the source of the discrepancy could not be identified, it cannot be assumed to be a systematic error, i.e. one which would affect the measurements of the new D3s with similar magnitude and direction as it would the old D3 bodies. 

Inconsistent data, flawed assumptions...bad science.


As for the exact formula DxO uses for their composite scores...yes, the precise formula is not published.

'Black box' methods...bad science.
 
I think we're done here.

47
Canon General / Re: When a Woman is Fed Up...
« on: July 27, 2014, 08:30:11 PM »
Looks like he didn't use a protective filter on his lens, which might have prevented all that damage. 

Oh well, as they say, "Hell hath no fury like..." 

 ;)

48
Lenses / Re: Canon EF 16-35 F/4L IS -- Reviews are trickling in...
« on: July 27, 2014, 08:06:24 PM »
I am just afraid of the day the new 16-35 2.8 III (or a 14-24) will be announced. I already have 14mm 2.8 II, 16-35 f/4L IS, TS-E17mm f/4L (and a Zeiss 21 2.8 ) and ... I will want/need it since (judging from the 24-70 2.8 II and the 16-35 4 IS ) it is almost certain that it will be coma corrected too.  :-[
I'm looking forward to the 16-35 f/2.8 III and/or the 1x-24. 

The reasonably high probability of a Canon 12/14-24L in the relatively near future is yet another reason I'll likely put the proceeds of selling my 16-35/2.8 II toward the TS-E 17/4L, rather than getting the 16-35/4L IS.

49
Third Party Manufacturers / Re: DXO uh-oh?
« on: July 27, 2014, 07:45:54 PM »
You can read about the methodology of their scores here:
http://www.dxomark.com/About/Sensor-scores

One of the tenets of scientific research is that you publish your methods in sufficient detail that someone knowledgable in the field can repeat your experiments and derive equivalent results.  Sorry, on the page you linked or elsewhere on their site, I cannot find where they state the formula used to calculate their scores.  If that is an oversight on my part, can you please link to where they publish that part of their methods?  If not, my claim of their "Image Science" being poor pseudoscience remains valid.

She wrote that as tongue 'n cheek, and it actually represents a sign of humility and willingness to be open to contrary points of view, signs of a good engineer/scientist.

So your contention is that to paraphrase her post, 'I cannot get consistent absolute measurements from one day to the next, so I'll present relative data instead,' is the sign of a good scientist/engineer?  Sorry, but I develop and validate assays for a living, and absolute data with significant inter-run or inter-day variability means a poor assay that needs to be corrected appropriately, if possible (and if not, an alternate assay must be developed).

What I am getting from your posts is a better idea of why your 'dot tune' method doesn't stand the test of independent validation, at least in my hands.

50
Third Party Manufacturers / Re: DXO uh-oh?
« on: July 27, 2014, 06:37:08 PM »
as a multi-system user I have to agree with DXO guys, they are honest, much more so than DPR or any other unscientific review sites online.


The problem is that DXO's "science" is in dispute. How can you trust something that produces inconsistent and obviously incorrect results?


Perhaps they should submit their 'science' to the Journal of Irreproducible Results.  They may even be worthy of consideration for an IgNobel Prize.

DxO documents their sensor testing procedure here:
http://www.dxomark.com/About/In-depth-measurements/DxOMark-testing-protocols/Noise-dynamic-range

DxO results have been independently reproduced at various times. For example:
http://www.dpreview.com/forums/post/33806693
http://www.dpreview.com/forums/post/33833501


Your DxO link describes one of their Measurements, which as I've stated on multiple occasions (at least dozens, if not hundreds on these forums) I find generally well done and useful (except when they make errors and deny it, which seems to occur mainly in their lens tests).  The problems are not with their Measurements, but with their Scores.  Can you provide a link where DxO explicitly describes how their Scores are calculated from the Measurements?  No, because they don't disclose the specifics of how those Scores are calculated.  Nor do they explicitly describe the bias inherent in their Scores.

FWIW, Peter van den Hamer suggests an approximation he states usually falls within 1-2 points: DxOMark_Sensor_Score = 59 + 4.3*(ColorDepth-21.1) + 3.4*(DynamicRange-11.3) + 4.4*log2(ISO/663) -0.2.  He also states, "My guess is that the actual formula is non-linear and may use (under some conditions) coefficients of 5/5/5 rather than 4.3/3.4/4.4."  His suggestion that the 'master formula' which DxO uses may be modified under some conditions further supports the claim that DxO's scoring is biased.  Yeah, that sounds like good science. NOT.

As for your 'independent reproduction,' I clicked your first link but to be honest, I stopped reading after, "For some obscure reason - sunspots or moon phase or other strangeness - photons are behaving better today, and I achieved higher FWC results for my D3's than I have before."  Sorry, but independent verification of poor pseudoscience with worse pseudoscience is even less valid than two wrongs making a right.

51
Third Party Manufacturers / Re: DXO uh-oh?
« on: July 27, 2014, 04:18:11 PM »
as a multi-system user I have to agree with DXO guys, they are honest, much more so than DPR or any other unscientific review sites online.

The problem is that DXO's "science" is in dispute. How can you trust something that produces inconsistent and obviously incorrect results?

Perhaps they should submit their 'science' to the Journal of Irreproducible Results.  They may even be worthy of consideration for an IgNobel Prize.

52
Beforehand it was always mentioned that the photos would be used be displayed in the Union Halls online gallery or possibly published in the news letter .  One thing I always require is that when it comes to use of my photos that I get proper credit for them, and they be used as agreed upon.

On the side of that trailer was one of the photos I provided for the newsletter...

I see words like 'mentioned' and 'agreed upon'.   Does that mean mentioned in a written agreement, and agreed upon by said agreement being signed by both parties?  If not, it seems reasonable that they could use an image which you provided to them for whatever they want. 

It could also be a simple error - someone put the image on a server, someone else found it, liked it and used it for the truck.

As for accusing a New Jersey union of breaking the law, I hear that can lead to other things getting broken...kneecaps, for example.  :o

53
Lenses / Re: Help me to decide: 35 vs 50mm
« on: July 27, 2014, 10:57:06 AM »
...the thing is, I really want to use a manual focus lens...


Simple solution.



Economical solution, too, beacuse when you no longer want to use a manual focus lens you only need to move a switch instead of buying a new lens.

 ;)

54
Third Party Manufacturers / Re: DXO uh-oh?
« on: July 27, 2014, 10:34:04 AM »
Look, I'll be easy on you and give you the chance to respond to one request at a time.

* Please explain how DxO is accomodating [f]or more clients more important to them.

First, you can explain why you think it would be a good idea for you to take remedial courses in reading comprehension and logical reasoning.

55
EOS Bodies / Re: 7D now marked as DISCONTINUED at Amazon
« on: July 27, 2014, 09:49:13 AM »
By eliminating the sensor they were able to make the most compact camera of all time that can still mount EF lenses. 


Lens2Scope has beaten them to it, albeit without colored pencils and a sketch pad.


56
EOS Bodies / Re: 7D now marked as DISCONTINUED at Amazon
« on: July 27, 2014, 09:35:04 AM »
I heard Canon is going to one-up the mirror less crowd by delivering the 7D2 as the first mirrorless *and* sensorless camera.

Bingo.  Nikon has made spotting scopes for years, and Canon will use the 7DII as an entrĂ©e into the spotting scope market.

57
Third Party Manufacturers / Re: DXO uh-oh?
« on: July 27, 2014, 09:30:57 AM »
Let me make it simple for you..

DxO is accommodating one or more of the clients more important to them (e.g., they are 'joined at the hip with Nikon', which you have been arguing against), or DxO are makes foolish business decisions?

1) Explain how DxO is accomodating or more clients more important to them
2) Explain your reasoning  behind using the phrase "joined at the hip with Nikon."

Let me try to help you read and comprehend what I originally wrote:

EDIT: or perhaps you're suggesting a third possibility that I intentionally dismissed, namely that Canon is a client but DxO chose to not display the logo of the leading manufacturer of dSLRs among their clients.  Possible reasons for that could be to placate other clients more important to theme, i.e. Nikon (which would certainly imply some sort of hip-joining) or simply because DxO is foolish.  Is that what you're suggesting?

In other words, I was providing plausible explanations for a possibility that I had already indicated I thought to be so unlikely that I didn't even mention it initially.

Seriously, look into some remedial education.  Maybe we can have this discussion someday when you've learned how to comprehend what you read.  Until then, it's merely a waste of time.

58
EOS Bodies / Re: 7D now marked as DISCONTINUED at Amazon
« on: July 27, 2014, 09:18:43 AM »
It's a sure sign that the 7D will soon be replaced with a mirrorless APS-H 1D-style camera called the 3Dx.

I don't see that sign of changing to APS-H. My guess, it will be an APS-C again.

Please check the battery in your sarcasm detector.

Which battery ?

I don't know where you guys suddenly see that it would be a APS-H. On which rumor do you all base to conclude it might be a APS-H ?

I don't get where you think it will be APS-C.  It's obvious that Canon will put a medium format sensor in the 7DII, to compete with the Phase One IQ280. 

59
Lenses / Re: Canon 24-70 f/4L IS disappointing?
« on: July 27, 2014, 08:20:51 AM »
I too have both 70-200 f/4 L IS and 70-200 f/2.8L IS II for the mere reason that when I bought the first the second didn't exist yet!

However there are cases where I need the 2.8 and cases where I don't so I can do with a lighter lens.

So I keep them both!

Indeed...  I bought the 70-300L as a travel telezoom, after owning the 70-200/2.8L IS II for a while.

60
EOS Bodies / Re: High Megapixel EOS on the Way as Mentioned by Canon
« on: July 27, 2014, 07:43:19 AM »
Quote
So, there is no official mention of a high-resolution camera by Canon.

But Canon must respond to the D800/E and a7R.  Canon must respond because (1) the 5DIII outsold the D800, and the a7R isn't really competitive in the relative sales numbers, and (2) Nikon responded by trying to boost sales with an incremental update and Sony responded by releasing a model with 1/3 the resolution.  So everyone can see why Canon must deliver a high resolution sensor, right?!?

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