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06-14-2014, 06:12 PM - 2 Likes   #1
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Equivalent aperture and FL - keepin' it real

.

Here's what places like dpreview should do more of:



There's ^^ an application of the dreaded equivalence (both equivalent FL *and* f-stop shown,) in a pretty graph.

Note that it's using the typical 135mm (FF) as the 'standard' reference anchor in this particular graph, but that's a choice that equivalence doesn't demand - there is no 'standard' with equivalence. So don't get mad about that and then attribute it to equivalence - that's just something that photographers and review sites do so we have a common way to compare how different FLs look on different formats. aps-c could be the standard anchor for FL, m43 could, it doesn't matter with regard to equivalence.

What's unusual is that dpreview, above, gives a nod to the physical realities and did a conversion with aperture too at the same time. Kudos.

Thoughts, foot-stompin'-angry or otherwise? (keep it civil or Parallax will shut it down! )

.


Last edited by jsherman999; 06-14-2014 at 06:21 PM.
06-14-2014, 06:41 PM   #2
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They've been doing those charts for a while. They are helpful if that's the info one is looking for.
06-14-2014, 08:09 PM - 1 Like   #3
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Total Light vs. Exposure - they are not the same and both very important

QuoteOriginally posted by filoxophy Quote
They've been doing those charts for a while. They are helpful if that's the info one is looking for.
Indeed. I should have perused the first pages of the reviews more carefully and given them credit where due.

Here's the section leading into that chart:



Total Light != exposure. Kudos again, dpr.

Or as I said to someone earlier who stated that caring about total light was 'silly' :

"...'total light' is important to any photographer who might like to get less image noise for a given exposure. You can't control total light for a given exposure in the same way you can control exposure itself - but you can make purchase decisions up front that will give you more total light for your typical shooting scenarios and available, affordable autofocus lenses - if that's what you're after. The majority of shooters who buy FF are after that. (As are the majority of aps-c shooters who choose that format over m43, or 1 inch sensors, etc.)

Has anyone reading his bought an aps-c DSLR system because you wanted (in part) better noise performance over a point n' shoot? Then you care about total light.
"




.

Last edited by jsherman999; 06-14-2014 at 08:23 PM.
06-14-2014, 08:55 PM - 2 Likes   #4
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"Never underestimate the difficulty of changing false beliefs by facts". — Harvard economist Henry Rosovsky

06-14-2014, 09:25 PM   #5
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Crickets. I hear crickets.
06-15-2014, 08:33 AM   #6
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Hmm... mocking doesn't go well with your "keep it civil" advice, oh wait, that was only for the others?
06-15-2014, 08:37 AM   #7
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QuoteOriginally posted by Kunzite Quote
Oh, so that's the problem: you're replacing everything you're being told with figments of your imagination.
Good luck with your Holy Crusade, but don't you think you're fighting it in too many threads?

Re threads: we're in the correct sub-forum for this, and it's a pretty important concept - even more so that Ricoh may be gearing up for a real FF release. If that happens, denial-as-reflex will fade as an affliction around here.

As long as you're here, care to comment on the chart?

.

Last edited by jsherman999; 06-15-2014 at 09:00 AM.
06-15-2014, 08:39 AM   #8
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jsherman, did you post this as a helpful link, or to draw out those who don't see things your way?

06-15-2014, 08:51 AM   #9
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QuoteOriginally posted by filoxophy Quote
jsherman, did you post this as a helpful link, or to draw out those who don't see things your way?
That's just it - it's not 'my way', it's a representation of physical reality.

There are multiple sources for this, multiple examples - some of the deniers like to frame it as 'that's how you see things, and it's wrong because I don't believe you,' and I'm trying to point out that it's not something I came up with out of the blue simply to dismay them.

In other words, if they have a beef with equivalence - I'm just the messenger, and they'll need to revisit that beef with a lot of messengers as time goes on.

The birth of new concepts in the mind can be a painful birth.

.
06-15-2014, 08:57 AM - 1 Like   #10
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QuoteOriginally posted by filoxophy Quote
jsherman, did you post this as a helpful link, or to draw out those who don't see things the correct way?
Fixed it for you.
06-15-2014, 09:03 AM   #11
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I edited my previous post - deciding after the fact that I don't really want a mocking contest - but whatever.

Yes, I can comment on that chart and add some personal observations made in the few decades I had contact with photography.
For example, I found out that many compact-using snapshooters don't care about DoF in the same sense we do. They would usually expect everything to be in focus (and in some cases, "upgrading" to a DSLR brought in a nasty surprise).
There were of course "success stories" with people going from compacts to DSLRs. However, we're not talking about shooting down to F16, they learned instead to use the limited DoF to their advantage.

Winder&jsherman999: You believing and repeating ad nauseum that yours is the One True Way doesn't make it so. It only shows that you're closing your minds to everything else.
There is nothing true in selecting a very limited - and in many cases some irrelevant - set of parameters in order to claim that images are "equivalent".
There is nothing true in twisting the meaning of the most basic optical notions such as focal length.
There is nothing true in claiming that a lens gives you noise.
And there is nothing true in mocking people who don't share your beliefs.

P.S. I will get a Pentax FF when it will be available (maybe next year, who knows?), and - as much as possible - I will shoot it at ISO 100; I will gladly explore every aspect that's different, just to see the equivalentionists cringe.

Last edited by Kunzite; 06-15-2014 at 09:10 AM.
06-15-2014, 09:24 AM   #12
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QuoteOriginally posted by Kunzite Quote
Winder&jsherman999: You believing and repeating ad nauseum that yours is the One True Way doesn't make it so. It only shows that you're closing your minds.
Again - it's not our way. We are the messengers. The facts can't be biased, and they can be verified, which you yourself can do if you wish. In other words, please don't just take our word for it, do your own research, like the dpreview authors who made the chart in the OP did.

.

QuoteQuote:
There is nothing true in selecting a very limited - and in many cases irrelevant - set of parameters in order to claim that images are "equivalent".
What specifically is not true about it? Is there something you don't agree with mathematically, or something that your experience specifically contradicts? If you're going to answer this, please be specific so we don't just trade loaded generalities.

Remember, 'equivalence' doesn't claim to make images the same, and it doesn't claim that what you always want to do is get equivalent images - it simply describes the differences between formats and uses the concept of equivalent images to do so.


QuoteQuote:
There is nothing true in claiming that a lens gives you noise.
It is precisely true that noise is a result of total light and sensor efficiency, and total light is determined in part by the lens, and it's entrance pupil diameter. Thus, you can select a lens that can give you less image noise than another lens. Are you denying this?


QuoteQuote:
And there is nothing true in mocking people who don't share your beliefs.
Not mocking, and it's not my beliefs, it's physical reality.

QuoteQuote:
P.S. I will get a Pentax FF when it will be available (maybe next year, who knows?), and - as much as possible - I will shoot it at ISO 100; I will gladly explore every aspect that's different, just to see the equivalentionists cringe.
To disprove equivalence (if that's what you're implying you will do ) you will need to break the laws of physics, or doctor your results.

If you want to show differences in equivalent images - heck, I can show you that. Bokeh, rendering, 'drawing', aberrations, sharpness are all lens-specific. Equivalence makes no claims otherwise, and doesn't include hose things. If you say it does you're setting up a straw-man.

.

Last edited by jsherman999; 06-15-2014 at 09:32 AM.
06-15-2014, 09:25 AM - 1 Like   #13
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QuoteOriginally posted by jsherman999 Quote
That's just it - it's not 'my way', it's a representation of physical reality.

There are multiple sources for this, multiple examples - some of the deniers like to frame it as 'that's how you see things, and it's wrong because I don't believe you,' and I'm trying to point out that it's not something I came up with out of the blue simply to dismay them.

In other words, if they have a beef with equivalence - I'm just the messenger, and they'll need to revisit that beef with a lot of messengers as time goes on.

The birth of new concepts in the mind can be a painful birth.

.
Believe me, I get it... I just feel like we've had this "discussion" recently. This new graph won't change any hearts and minds. Frankly I don't understand the fervor on either side of the equivalence divide.

I wish you all a productive and civil conversation. Over and out...
06-15-2014, 09:40 AM   #14
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QuoteOriginally posted by Kunzite Quote
You believing and repeating ad nauseum that yours is the One True Way doesn't make it so. It only shows that you're closing your minds to everything else.
It doesn't matter how many times you try to tell me that 2+2=5, I'm not going to agree with you. In that regard I have closed my mind. 2+2=4 and that is "One True Way".
06-15-2014, 10:51 AM   #15
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QuoteOriginally posted by Winder Quote
t doesn't matter how many times you try to tell me that 2+2=5, I'm not going to agree with you. In that regard I have closed my mind. 2+2=4 and that is "One True Way".
2 cups + 2 cups = 1 quart. So much for the 'one true way'.
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