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05-31-2014, 08:56 AM   #241
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QuoteOriginally posted by jsherman999 Quote
Yes, it does. In fact he's stated that very thing in forums before. There's always the caveat that the available lenses have to allow for it - ie have to have a large enough linear aperture - but one of the underlying tenets of equivalence is that any format size can make any image, given the right lens. It's kind of a basic thing you need to understand if you claim to understand equivalence.
No, he doesn't - read the article. And if he claimed contrary, he's contradicted himself (but most likely you are not remember correctly)
His "equivalence" is based on 5 parameter, and only on them: perspective, framing, DOF, shutter speed, display dimensions; this will give you "equivalent" images. For "identical" images, more conditions have to be met (and even then, there are some assumptions that he's unknowingly making, things are more complicated than that).

QuoteOriginally posted by ElJamoquio Quote
Compacts don't have lenses? It's very clear that the OP was talking about P&S / Bridge cameras, which clearly have focal lengths labeled on the front of their lenses (sometimes on the side) as equivalent focal lengths.
1. You generalized, claiming that manufacturers aren't "using focal length on their lenses" - they surely do, on ILCs.
2. It's very clear the video is not about compacts - so a generalization based on those is an intentional attempt at misleading.
But since "Kunzite" is so similar to "Rondec", maybe "compacts" and "MFT", "APS-C", "FF" can be confused, too.

05-31-2014, 09:10 AM   #242
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QuoteOriginally posted by Kunzite Quote
1. You generalized, claiming that manufacturers aren't "using focal length on their lenses" - they surely do, on ILCs.
Sometimes they use actual focal length. Sometimes they use equivalent focal length. Sometimes they do both. I never said that ILC's never use actual focal length, that would be a stupid statement.

QuoteOriginally posted by Kunzite Quote
2. It's very clear the video is not about compacts
Compacts, bridges etc etc is what I said. And I would call that Olympus that was compared to a 300mm f/2.8 a compact.


QuoteOriginally posted by Kunzite Quote
- so a generalization based on those is an intentional attempt at misleading.
But since "Kunzite" is so similar to "Rondec", maybe "compacts" and "MFT", "APS-C", "FF" can be confused, too.
This is the friendly pentax forum, so I already apologized to you once.
05-31-2014, 09:37 AM   #243
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Actually you said exactly that: "If they were using focal length on their lenses you'd have a point, but the manufacturers aren't."
Pal Jansen wasn't talking about compacts, Tony wasn't talking about compacts when he made those silly statements about "not trusting" camera manufacturers - exemplifying with MFT, APS-C, FF (only much later in the video, he's using some compacts as examples) - and you weren't qualifying your words at all; that's a general statement.
The compacts are nothing more than a red herring in this discussion.
05-31-2014, 10:12 AM   #244
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QuoteOriginally posted by Kunzite Quote
Actually you said exactly that: "If they were using focal length on their lenses you'd have a point, but the manufacturers aren't."
Pal Jansen wasn't talking about compacts, Tony wasn't talking about compacts when he made those silly statements about "not trusting" camera manufacturers - exemplifying with MFT, APS-C, FF (only much later in the video, he's using some compacts as examples) - and you weren't qualifying your words at all; that's a general statement.
The compacts are nothing more than a red herring in this discussion.
I'm sorry again. "the manufacturers aren't in the examples that the OP was referring to".

Is the statement clearer to you now?

Please stay friendly! Sometimes people who aren't critical of Pentax get banned too.

05-31-2014, 10:34 AM   #245
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Sorry, nope, it still doesn't make sense to me; Pal Jensen didn't mention specific manufacturers.

Recognizing a red herring is not a reason for me getting banned, I'd think; nor should I agree with you or other extreme claims (like those in the video) just for the sake of "friendliness".

Last edited by Kunzite; 05-31-2014 at 10:41 AM.
05-31-2014, 07:45 PM   #246
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QuoteQuote:
Can you give one example of an interchangeable lens marked with some "equivalent" focal length?
I have never seen any. The sins of omission are the product of the marketing departments who, in the advertisements, let consumers thing they're getting a half-equivalency-converted "28-300 f/2.8" lens that can serve the shooter as well as a 28-300 2.8 lens on a larger format.. for example. We've seen these ads, and I've personally witnessed salespeople trying to sell a camera on similar false merits - once I'm certain on purpose (because I know the saleperson and I know he knew better,) and once because the sales clerk himself didn't know what he was talking about.

We can see the damage occasionally post-purchase, even among the ranks of 'enthiusiasts'.

Tell me (anyone) - what would you say if an m43 shooter (sorry northcoastgreg, just paraphrasing an example I saw on dpreview, your kit is nice) say this:

"I don't know what's so great about your 77mm f/1.8 Limited - I have a 75mm f/1.8 for my Olympus m/43, same FL and just as fast, so it gives me the same shutter speed and noise performance on my camera."

How would you answer that? What would you point out, what specifically would you try to correct, if anything?

.
06-01-2014, 03:09 AM   #247
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QuoteOriginally posted by jsherman999 Quote
I have never seen any. The sins of omission are the product of the marketing departments who, in the advertisements, let consumers thing they're getting a half-equivalency-converted "28-300 f/2.8" lens that can serve the shooter as well as a 28-300 2.8 lens on a larger format.. for example. We've seen these ads, and I've personally witnessed salespeople trying to sell a camera on similar false merits - once I'm certain on purpose (because I know the saleperson and I know he knew better,) and once because the sales clerk himself didn't know what he was talking about.

We can see the damage occasionally post-purchase, even among the ranks of 'enthiusiasts'.

Tell me (anyone) - what would you say if an m43 shooter (sorry northcoastgreg, just paraphrasing an example I saw on dpreview, your kit is nice) say this:

"I don't know what's so great about your 77mm f/1.8 Limited - I have a 75mm f/1.8 for my Olympus m/43, same FL and just as fast, so it gives me the same shutter speed and noise performance on my camera."

How would you answer that? What would you point out, what specifically would you try to correct, if anything?

.
Not knowing about that specific Olympus lens, I don't know that I could make a whole lot of comments. a 77mm on APS-C or 75mm on four thirds are both probably going to be used for portraiture, meaning that you actually will get similar photos in "real life." The differences will be in the glass itself -- rendering, contrast, sharpness wide open, etc. Particularly at this focal length, you will have plenty narrow depth of field with both lenses and so I don't think equivalence helps out a lot here.

As to the noise performance thing, Olympus cameras have nice noise performance and really nice jpeg engines. Depending on the iso you are shooting, I doubt you would see a difference. At iso 6400, you might, at 800 and below, probably not.

From a personal stand point, I find the 77 a little long on my crop cameras and I think 75 would be quite long on four thirds.

Edit: The biggest culprits for doing weird things with focal lengths are folks like Scott Kelby. I think he knows what he is doing, but in his digital books, he was seriously confusing about what happens to lenses on a crop camera.
06-01-2014, 06:57 AM - 1 Like   #248
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QuoteOriginally posted by jsherman999 Quote

Tell me (anyone) - what would you say if an m43 shooter (sorry northcoastgreg, just paraphrasing an example I saw on dpreview, your kit is nice) say this:

"I don't know what's so great about your 77mm f/1.8 Limited - I have a 75mm f/1.8 for my Olympus m/43, same FL and just as fast, so it gives me the same shutter speed and noise performance on my camera."

How would you answer that? What would you point out, what specifically would you try to correct, if anything?

.
I truly hope we would sit together and look at the shots we are taking (... I mean in real life).
Hopefully we would discuss about her/his idea of photographie and what she/he wants to show and express with the shots and my idea of photographie. For sure that would be so much more relevant to the shots we take (again, in real life) than such a thing like theoritcal equivalence.

06-01-2014, 08:18 AM   #249
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QuoteOriginally posted by Rondec Quote
Not knowing about that specific Olympus lens, I don't know that I could make a whole lot of comments. a 77mm on APS-C or 75mm on four thirds are both probably going to be used for portraiture....
QuoteOriginally posted by volley Quote
I truly hope we would sit together and look at the shots we are taking (... I mean in real life).....


Let's say we're beyond the Kumbaya, everything-takes-great-shots-just-go-out-and-shoot part of the conversation:




(sorry, love that movie)



....and it's moved into a technical question/assertion, possibly one that might influence another potential buyer who's also interested in the answer and might make a significant kit purchase based on it..

How do you answer this, knowing what you know?

"I don't know what's so great about your 77mm f/1.8 Limited - I have a 75mm f/1.8 for my Olympus m/43, same FL and just as fast, so it gives me the same shutter speed and noise performance on my camera."



.
06-01-2014, 10:25 AM   #250
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I will remind you once again that Joseph James' "equivalence" does not include noise.
It's all in here:
Equivalence
Search for "MYTHS AND COMMON MISUNDERSTANDINGS", the "assuming "equivalence" is based on equal noise" section.

Noise have to be measured and observed.
06-01-2014, 11:42 AM   #251
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QuoteOriginally posted by jsherman999 Quote
Let's say we're beyond the Kumbaya, everything-takes-great-shots-just-go-out-and-shoot part of the conversation:


.
I am sorry, but although english is not my native language I am fairly sure that this is not what I have said.

QuoteOriginally posted by jsherman999 Quote
....and it's moved into a technical question/assertion, possibly one that might influence another potential buyer who's also interested in the answer and might make a significant kit purchase based on it..

How do you answer this, knowing what you know?

"I don't know what's so great about your 77mm f/1.8 Limited - I have a 75mm f/1.8 for my Olympus m/43, same FL and just as fast, so it gives me the same shutter speed and noise performance on my camera."
.
I am convinced that it would not be a very smart idea to base a purchase decision for a significant kit on "equivalence". Is this what you are suggesting?

The examples you have listed (m/43 with a 1.8/75mm and APS-C with 1.8/77mm limited) are so close that it is much more sensible (in my opinion) to look at actual shots taken with the combos to find out which results you like better. The differences which should trigger the purchasing decision you are mentioning are more likely differences like ergonomics and handling and feeling comfortable with the equipment than in an equation for equivalence.

Please don't get me wrong: if equivalence is important for you that is perfectly fine. I just can't convince myself to find it relevant.
06-01-2014, 11:45 AM   #252
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For me, having the lenses that do the things I want was critical to my purchasing decisions. For me, equivalence took a several-day comparison and brought it down to seconds. After that, all I needed to do was look at bokeh, rendering, sharpness, etc, and it was much easier.
06-01-2014, 01:35 PM   #253
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QuoteOriginally posted by jsherman999 Quote
Let's say we're beyond the Kumbaya, everything-takes-great-shots-just-go-out-and-shoot part of the conversation:




(sorry, love that movie)



....and it's moved into a technical question/assertion, possibly one that might influence another potential buyer who's also interested in the answer and might make a significant kit purchase based on it..

How do you answer this, knowing what you know?

"I don't know what's so great about your 77mm f/1.8 Limited - I have a 75mm f/1.8 for my Olympus m/43, same FL and just as fast, so it gives me the same shutter speed and noise performance on my camera."



.
I sense some irritation, Jay. You could take your same case and compare the FA 77 f1.8 on a K3 with a Nikon 85mm f1.8 on a D600. I just wouldn't choose based on "equivalence," but rather based on rendering, sharpness, etc. Both lenses should be more than capable of narrow depth of field and once again, at most isos, you probably won't see a big difference in camera performance.

Obviously, you would choose the D600, but particularly with longer lenses, I think it is a tougher case than with wide angles, where you are more likely to see an actual difference.
06-01-2014, 02:10 PM   #254
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QuoteOriginally posted by Rondec Quote
I don't know that I buy this 20 percent increase. Sounds like a made up statistic to me.
20% sounds about right to me—in the ball park at least. Of course, there are a number of other variables that could skew things, including lens resolution and pixel density. Not so long ago I saw a comparison between an image shot with a 12 MP Canon FF camera and the 24-105 lens at 24mm and f5.6 and an image shot with the Olympus EM-1 and the 12-40 lens at 12mm and f2.8. At 100% resolution, they looked equally sharp and it was difficult to say which was "better."

But more to the point, 20% may sound significant, but it really isn't. If you're making a 20" by 20" print, adding 20% resolution will allow you to make about a 22" by 22" print. How significant are those extra two inches?

This is the problem with throwing around numerical specs, whether they are generated by equivalency equations or DxOMark: very few people know what these numbers mean in terms of visual experience. And yet it is the visual experience that counts, not the physics behind that experience. Most of us take photos so that we can experience them visually, not so that we can attain specific numerical specs.

QuoteOriginally posted by ElJamoquio Quote
Humor me, now, you told me that the D7100 + 17-55 was better than the D610+24-85. I'm interested in the specs, and could easily sell my setup.
I think it would be a huge mistake to sell your D610 kit based on numerical specs. Look at images from each combo and then decide. Look, don't measure.
06-01-2014, 04:36 PM   #255
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QuoteOriginally posted by northcoastgreg Quote
20% sounds about right to me—in the ball park at least. Of course, there are a number of other variables that could skew things, including lens resolution and pixel density. Not so long ago I saw a comparison between an image shot with a 12 MP Canon FF camera and the 24-105 lens at 24mm and f5.6 and an image shot with the Olympus EM-1 and the 12-40 lens at 12mm and f2.8. At 100% resolution, they looked equally sharp and it was difficult to say which was "better."

But more to the point, 20% may sound significant, but it really isn't. If you're making a 20" by 20" print, adding 20% resolution will allow you to make about a 22" by 22" print. How significant are those extra two inches?
20% was the difference between a $1300 lens on the top-of-the-Nikon-line APS-C without an anti-alias filter and a $600 FF lens on the bottom-of-the-line camera with an anti-aliasing filter. (or sometimes $300 as a package deal).
20% was also DxOMarks' reported difference between the ~$1300 16-50mm and the 18-55 kit lens.

Is it worth it for everybody? Absolutely not.

Now go to say, a normalish fast lens...



QuoteOriginally posted by northcoastgreg Quote
I think it would be a huge mistake to sell your D610 kit based on numerical specs. Look at images from each combo and then decide. Look, don't measure.
I want the best lenses that will do what I want them to do. That involves filtering by needs and then looking at bokeh, rendering, etc, as I said in the post above and many many times.

But people here have told me that a 17-55 would be better, and I want to know if it'll have better noise performance compared to my F/3.5-F/4.5... one of my biggest unfilled needs in Nikon is the ability to take pics in low light. Will the D7100 be better?
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