October 21, 2014, 12:18:09 PM

Author Topic: Canon may be expensive but...  (Read 21748 times)

neuroanatomist

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Re: Canon may be expensive but...
« Reply #30 on: January 31, 2013, 08:04:55 PM »
I have already answer that, go back to page 2, BUT Canon, Leitz , Hasselblad Nikon  etc  has real MTF equipments and measuring of the lenses  , not to be mixed by Photozone and others "MTF" tests .
There is no problem to measure a Canon lens at Hasselblad MTF lab in Gothenburg and compare that to others

I do not see an answer.  Are you saying that the MTF curves published on Canon's (and Nikon's) websites represent real, empirically measured data?

I wrote
we dont know if this is estimated MTF, Canon and Nikon has a predilection to exhibit estimated MTF results  to impress
Which means estimating, calculating
And please, if you are going deliberately misunderstand me, keep going.

Ahhh...but we do know. Canon's published MTF curves are calculated/theoretical, not empirically measured. 

You have two possibly conflicting statements above - "Canon, Leitz , Hasselblad Nikon  etc  has real MTF equipments and measuring of the lenses," vs. "Canon and Nikon has a predilection to exhibit estimated MTF."  Certainly it's possible that Canon has the instrumentation to empirically measure lens MTF (as Zeiss does, for example), and yet chooses to not show those data for their lenses.  What is your evidence that Canon has such instrumentation?
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Re: Canon may be expensive but...
« Reply #30 on: January 31, 2013, 08:04:55 PM »

yogi

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Re: Canon may be expensive but...
« Reply #31 on: January 31, 2013, 08:37:31 PM »
Here we go again. I have no idea, but  Neuro sounds more plausible, as usual. ::)
« Last Edit: January 31, 2013, 08:39:43 PM by yogi »

yogi

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Re: Canon may be expensive but...
« Reply #32 on: January 31, 2013, 08:38:50 PM »
Meant to say also: good luck Neuro ;D

J.R.

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Re: Canon may be expensive but...
« Reply #33 on: January 31, 2013, 09:16:27 PM »
Popcorn anyone ;D ;D ;D
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serendipidy

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Re: Canon may be expensive but...
« Reply #34 on: January 31, 2013, 09:29:09 PM »
Good night everyone. Sleep well and dream of L lenses :)
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BrettS

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Re: Canon may be expensive but...
« Reply #35 on: January 31, 2013, 09:30:38 PM »
Popcorn anyone ;D ;D ;D


I can tell you people that I have got stringent regulations about my use of   
language from CR, but sometimes I wonder if it not is better to tell  some people here at CR that they have to large costumes and shall not discuss things they not have any knowledge/clue about.
Time 0318 so there will not be any popcorn for me
good night

Only a bombastic, arrogant narcissist would say this in a discussion with neuro. Good luck with your charts.

neuroanatomist

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Re: Canon may be expensive but...
« Reply #36 on: January 31, 2013, 09:39:11 PM »
This smells head -room over all, you didn't know how a sensor works, no cameras)

Actually, you were the one in error in the thread to which you're referring, and ultimately, you admitted it.  We actually agreed on most points in that thread, though - so if I do not understand how a sensor works, then neither do you.

Regardless, the point about MTF measurement really isn't worth arguing over.  Sleep well...
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Re: Canon may be expensive but...
« Reply #36 on: January 31, 2013, 09:39:11 PM »

yogi

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Re: Canon may be expensive but...
« Reply #37 on: January 31, 2013, 10:01:16 PM »
Here we go again. I have no idea, but  Neuro sounds more plausible, as usual. ::)
Plausible?
meet me with facts

Here is a fact. I had a bad day at work, and had to work overtime. Think I will quit for the night. Sleep tight and dont let the bedbugs bite. :P

babiesphotos

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Re: Canon may be expensive but...
« Reply #38 on: January 31, 2013, 10:40:12 PM »
Popcorn anyone ;D ;D ;D


I can tell you people that I have got stringent regulations about my use of   
language from CR, but sometimes I wonder if it not is better to tell  some people here at CR that they have to large costumes and shall not discuss things they not have any knowledge/clue about.
Time 0318 so there will not be any popcorn for me
good night

Only a bombastic, arrogant narcissist would say this in a discussion with neuro. Good luck with your charts.

Agreed. I've been on this forum less than a month, and I can already see that you don't argue with neuro. I'm glad he spends his time around here...

dave

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Re: Canon may be expensive but...
« Reply #39 on: January 31, 2013, 10:46:15 PM »
I feel bad for starting this thread. It really was only a piece of info! :-[

J.R.

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Re: Canon may be expensive but...
« Reply #40 on: January 31, 2013, 10:56:32 PM »
I feel bad for starting this thread. It really was only a piece of info! :-[

I know exactly how you feel. I started a thread on ISO 50 and you should have seen where THAT ended up ...

http://www.canonrumors.com/forum/index.php?topic=12437.255
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dave

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Re: Canon may be expensive but...
« Reply #41 on: January 31, 2013, 11:35:20 PM »
I feel bad for starting this thread. It really was only a piece of info! :-[

I know exactly how you feel. I started a thread on ISO 50 and you should have seen where THAT ended up ...

http://www.canonrumors.com/forum/index.php?topic=12437.255

I remember that one. Classic.

That was definitely a time when you would be justified in saying to yourself "it's not me, it's you!"

Hi Mikael, long time no see!

dave

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Re: Canon may be expensive but...
« Reply #42 on: January 31, 2013, 11:47:42 PM »
then read the discussion again.
and read the suedes answer
I take it the answer was "yes".

I would think this concludes this argument series.
As far as I can understand from the [considerably more than!] somewhat confused string of comments in this thread, no party is/was actually strictly incorrect, since both parties are constantly avoiding the "Yes, but I'm talking about...." pretext of the responding posts.

Though I cannot help but feel that at least one side of the argumentation has gone out of it's way to not read the intended meaning of the "opposite side's" statements and argumentation. And the undertone of constant provocation isn't very unflattering.

This isn't meant to be condescending towards Mikael - since he is well aware of both his light dyslexia and his short temper - but this thread feels like a kindergarten playground where a pack of children are trying to provoke a dyslectic kid with very short temper into doing something stupid and aggressive while the teachers are watching - so they can say that "he started the violence!" and point the blame to him - and get him expelled. As I said: Not a very flattering impression.

In the end, from a factual PoV:

HTP does not in any case UNLESS the one-off case where the starting point is ISO100 lower absolute photometric exposure. At set ISOs 200-800 it does however increase the electronic noise pollution in the finished image somewhat in Canon cameras.
Exposure is exposure is exposure, and exposure sets the photon noise level in the image. It's set by the scene light emittance modulated by shutter speed and lens T-stop (aperture + losses), and actually also for all practical considerations: QE of the sensor. Not by ISO - though the ISO setting can change aperture and/or shutter speed when the camera is in auto- mode (anything but "M" mode), it's a secondary effect. ISO changes setting, setting changes exposure.
ISO in digital cameras is a translating factor between exposure (exposure x QE = cell charge) and raw file ADU value.
The amount of headroom available in a camera can NEVER be higher than when the camera is used on base ISO (ISO100 in the case discussed here) - Since the highest DR is always at base ISO, unless the construction is seriously flawed (actually totally botched!). This means that ISO200 + HTP has the same 'potential' headroom, since the actual physical amplification is set at ISO100, not 200
ISO50 (or more generally "lower than actual base ISO") settings are useless for raw shooters, but may be of some use for jpg shooters.


Feel free to add constructive criticism, or point out any error(s). But be very ashamed if this post is considered OT and erased.

Excellent, I agree!

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Re: Canon may be expensive but...
« Reply #42 on: January 31, 2013, 11:47:42 PM »

sanj

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Re: Canon may be expensive but...
« Reply #43 on: February 01, 2013, 12:47:43 AM »
Wondering why Canon, Nikon would NOT measure actual lenses?
« Last Edit: February 01, 2013, 01:37:33 AM by sanj »

rpt

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Re: Canon may be expensive but...
« Reply #44 on: February 01, 2013, 01:39:36 AM »
Wondering why would Canon, Nikon would NOT measure actual lenses?
It's a numbers game. If they produce ten thousand lenses of a particular lens (I picked that number out of the air - I could be waaaaaaay out on that one...) and each MTF chart has at least eight squiggles, and each squiggle needs at least fifteen points (with zoom, double that - two charts...) that is a lot of points! So which point do you publish? Best? Worst? Average? Median? Mode? I guess simpler not to publish and statistically QA lenses assuring quality is as expected...

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Re: Canon may be expensive but...
« Reply #44 on: February 01, 2013, 01:39:36 AM »