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04-18-2014, 07:55 AM   #196
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QuoteOriginally posted by jsherman999 Quote
Granted. We were sticking to an equivalence discussion (I thought,) but it's true, the two VL lenses are going to be sharper - but they need to be, as their results are magnified 2x compared to FF. And although a garden-variety 50mm is 'nothing special', all 50mm's are pretty doggone sharp, even sometimes at f/2. My 50 1.8D does very well on my D800. There may be other IQ factors like color transmition, flare control and bokeh too.

Two big factors to keep in mind: The VLs are MF only, and the 17 and 25 go for over $2000 combined. If you're choosing m43 for cost reasons and want to shoot widish-normal to approximate FF, you just blew your cost control

But if you want to shoot m43, cost doesn't matter and you're OK with MF... that's a pretty sweet combo (good M43 body + VL 17 + 25f/0.95) although the VL's aren't small.

.
I agree about the manual focus aspect. Not particularly appealing to me, personally, but supposedly with a nice EVF it is not too hard to manual focus.

I just think that somehow lenses are graded on maximum aperture and other aspects -- contrast, micro contrast, build of lens, flare resistance, sharpness, vignetting, and rendering of out of focus areas get diminished as a result. I do think that lenses like the FA limiteds, many of the Leica lenses, etc don't look that different so far as specs go, but do have the ability to create images that are a cut above. But of course, you pay a lot more for that as well.

04-18-2014, 08:23 AM   #197
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QuoteOriginally posted by jsherman999 Quote
the two VL lenses are going to be sharper .
Sincerely doubt it. They're likely sharper on a lp/mm basis but almost assuredly not on a lp/ph basis for cameras available today.

---------- Post added 04-18-14 at 08:23 AM ----------

QuoteOriginally posted by Rondec Quote
I agree about the manual focus aspect. Not particularly appealing to me, personally, but supposedly with a nice EVF it is not too hard to manual focus.

I just think that somehow lenses are graded on maximum aperture and other aspects -- contrast, micro contrast, build of lens, flare resistance, sharpness, vignetting, and rendering of out of focus areas get diminished as a result. I do think that lenses like the FA limiteds, many of the Leica lenses, etc don't look that different so far as specs go, but do have the ability to create images that are a cut above. But of course, you pay a lot more for that as well.
Yuppers.
04-18-2014, 08:38 AM   #198
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QuoteOriginally posted by Rondec Quote
I agree about the manual focus aspect. Not particularly appealing to me, personally, but supposedly with a nice EVF it is not too hard to manual focus.

I just think that somehow lenses are graded on maximum aperture and other aspects -- contrast, micro contrast, build of lens, flare resistance, sharpness, vignetting, and rendering of out of focus areas get diminished as a result. I do think that lenses like the FA limiteds, many of the Leica lenses, etc don't look that different so far as specs go, but do have the ability to create images that are a cut above. But of course, you pay a lot more for that as well.
Completely agree and I have always felt that way. In Jjames' equivalence article, he takes pains to make sure those aspects need to be considered but are not part of 'equivalence', and that point has raised hackles in people who just can't understand why the scope of the equivalence discussion can't be expanded to include their own priorities

Think of it this way: When making buying decisions, everything needs to be considered, including perhaps equivalence - but equivalence itself doesn't include everything. An equivalence discussion is just a subset of an overall "what aspects and features are important to me" discussion. Equivalence mainly comes into play when the question is something like, "can I get the same FOV and noise performance on m43 with a Panasonic 14mm f/2.5 prime as I can with a 28mm f/2.8 prime on aps-c or FF?"

Last edited by jsherman999; 04-18-2014 at 08:49 AM.
04-18-2014, 08:40 AM   #199
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QuoteOriginally posted by jsherman999 Quote
Completely agree and I have always felt that way. In Jjames' equivalence article, he takes pains to make sure those aspects need to be considered but are not part of 'equivalence', and that point has raised hackles in people who just can't understand why the scope of the equivalence discussion can't be expanded to include their own priorities

Think of it this way: When making buying decisions, everything needs to be considered, including perhaps equivalence - but equivalence itself doesn't include everything. Equivalence mainly comes into play when the question is something like, "can I get the same FOV and noise performance on m43 with a Panasonic 14mm f/2.5 prime as I can with a 28mm f/2.8 prime on aps-c or FF?"
I think we agree. I just was a little bothered by your comment about your 200 dollars lenses performing as well as his 1500 dollars lenses.

04-18-2014, 09:05 AM   #200
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QuoteOriginally posted by ElJamoquio Quote
Sincerely doubt it. They're likely sharper on a lp/mm basis but almost assuredly not on a lp/ph basis for cameras available today.[COLOR="Silver"]
I was thinking about a sensorless bench test like Roger Cicala (lensrenrals) uses - the VLs will likely test out resolving more when stopped down a bit. At the same display sizes on varying MP densities and MP counts, all bets are off, especially considering lp/ph..and indeed on photozone the 50 1.8 on the D3x comes out much higher in lp/ph than the 25 f/0.95 on the Panasonic GF1, but that's to be expected. Suffice to say those f/0.95 FVLs may have some vignetting and sharpness issues wide-open, but they still are optical wonders when you think about it and I would take one as a gift any day

---------- Post added 04-18-14 at 10:07 AM ----------

QuoteOriginally posted by Rondec Quote
I think we agree. I just was a little bothered by your comment about your 200 dollars lenses performing as well as his 1500 dollars lenses.
(I still bet they pretty much would in most side-side comparisons. But that's another discussion. )
04-18-2014, 10:04 AM   #201
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QuoteOriginally posted by jsherman999 Quote
I was thinking about a sensorless bench test like Roger Cicala (lensrenrals) uses - the VLs will likely test out resolving more when stopped down a bit. At the same display sizes on varying MP densities and MP counts, all bets are off, especially considering lp/ph..and indeed on photozone the 50 1.8 on the D3x comes out much higher in lp/ph than the 25 f/0.95 on the Panasonic GF1, but that's to be expected. Suffice to say those f/0.95 FVLs may have some vignetting and sharpness issues wide-open, but they still are optical wonders when you think about it and I would take one as a gift any day

---------- Post added 04-18-14 at 10:07 AM ----------



(I still bet they pretty much would in most side-side comparisons. But that's another discussion. )
It is the whole pixie dust thing. Does the FA 31 limited have special rendering or not? How about the FA 77? I personally think they do, but compared to 35mm f1.8/85mm f1.8 lenses available from Canon/Nikon, they aren't exactly steals.

(FA 77 photo)



(FA 31 photo)

04-18-2014, 11:05 AM   #202
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QuoteOriginally posted by Rondec Quote
It is the whole pixie dust thing. Does the FA 31 limited have special rendering or not? How about the FA 77? I personally think they do, but compared to 35mm f1.8/85mm f1.8 lenses available from Canon/Nikon, they aren't exactly steals.
You know me, I'm a big believer in the pixie-dusted FA Limiteds, and I sometimes get slammed when I try to describe it aesthetically to Nikonians (& some Pentaxians)

It's also a big part of the reason I've been continually carping for 4 years for Pentax to deliver FF - time to bring the real power home to the FA Limiteds so their pixie dust can get supercharged!
04-18-2014, 01:29 PM   #203
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QuoteOriginally posted by jsherman999 Quote
Joseph Wisniewski talks about how he was trying to describe equivalence (FOV and DOF, not just FOV, how the F-stops meant different things to the resulting images too between formats, not just FL) before there was a handy label for it, back in the 80's
The irony is, I think equivalence would have been more useful back in the day, when more people were shooting widely disparate formats. Photographers can argue over whether the ~1 stop difference between APS-C and FF qualifies as "significant"; but there's really no argument when comparing 8 by 10 large format with 35mm.

QuoteOriginally posted by jsherman999 Quote
The main reason I think it's too bad more people don't understand it is because the whole reason FF is even better in shot-noise performance than smaller formats is described by equivalence
I suspect this is sort of tilting at windmills. Many (if not most) photographers just aren't interested in anything that smacks of technical. They will avoid aperture equivalency calculations in just the same way they avoid the equations that let you calculate the correct exposure when using manual flash. Many photographers are artistic types who are aesthetic and intuitive in their orientation, rather than technical or scientific. I don't think such people can ever be brought to appreciate, let alone understand, equivalence.

Although I'm not completely immune to narrow DOF photography (after all, I own a 50mm f1.2 lens), I prefer a more intuitive, perceptual approach. I prefer to see what a lens/sensor combination does in "real world" photography, rather than look at or crunch the numbers. I was once more into measurements and numbers; but over time I found that the numbers often did not correlate with my perceptual experience, so I stopped worrying about numbers and instead stick to what I can see. And so, while its entirely possible that a one stop difference (which to some of us really doesn't seem like much) might just wind up being that X factor when it comes to a particular image, just stating that in an abstract formula means nothing to me.

04-18-2014, 01:37 PM   #204
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QuoteOriginally posted by HavelockV Quote
That is plain nonsense. "Absolute aperture" in millimeters would be a static value based on the actual physical reality of a physical lens diameter and the physical size of the aperture.

Put a converter on your lens and the absolute aperture doesnt change as your physical object doesnt change, but the photographic result incl. DoF changes a lot. The resulting F-Stop changes but the absolute aperture not.
Sorry, you're right about the DOF. Since DOF is not a precise value, but a matter of perception, viewing at a higher magnification will change it. Cropping and then viewing at the same size as before will have the same effect. I should have qualified that part.

The rest holds true though. Total light gathered for a given object in the scene, as long as it fits in the frame, is this same no matter how many teleconverters you put on (minus transmission losses). Put a 1.4x converter on, and the object takes up 2 times more area and has 2 times less light per sensor area which is what you use for exposure. Light per object area is the same. If your field of view is the same, but the absolute aperture is greater, then the total light gained per scene increases. This is the fundamental reason of why "larger sensors have better low light performance", something that everyone seems to take for granted, but few understand why. No, it has nothing to do with "pixel size".

Same goes for the ability to distinguish two points of light right next to each other (i.e. "detail"). This is limited by absolute aperture due to diffraction. If you have an extremely high pixel density, and can keep cropping without running into a pixel limit, you will see that at 200mm f/2.8 is capable of resolving miniscule detail that a 400mm f/5.6 can (assuming these are good lenses that are diffraction limited rather than abberation limited in the center), but at 100mm f/2.8 you cannot, no matter how much you crop or how many teleconverters you add. Teleconverters are only useful when you are limited by the number of pixels (how much you can crop) before you run into diffraction limitations.

Last edited by Cannikin; 04-18-2014 at 02:07 PM.
04-18-2014, 02:00 PM   #205
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QuoteOriginally posted by jsherman999 Quote
Do you have all the manual focus Voigtlander f/0.95 lenses for your m43? If you do, then you'll be able to approximate what I can get with my autofocus $110 50 f/1.8d, a $200 35 f/2, $285 85 f/1.8d, etc

Go for it!


BTW those are reportedly great lenses.



So are you sticking with an equivalence discussion, or are you moving completely into the 'crop = reach' camp? It's not complete fallacy as it does show some practical shooting realities, in that with long telephoto, pixel density taken into account, with high-quality smaller formats (not P&S) you can get similar results for a lot less size and money than FF... But if money and size is not an object (think: Olympic, professional sports photographers on the sidelines - not shooting m43,) and we stick with equivalence, there's nothing an m43 camera can't do that aps-c or FF can't do there either with telephoto.

But maybe if I get time I will show an equivalent 300mm shot anyway, these threads are always better with images!

---------- Post added 04-18-14 at 07:58 AM ----------



?? TC is effectively changing the focal length, though, by cropping/magnifying. Or am I misunderstanding your assertion.

So what can you do with this lens that can't be done with m43? Really, in practical terms, what kind of shot will you produce out of this lens? What kind of shot that if put side by side with another shot will make the viewer go, "THIS is the one shot with a full frame with a bank breaking lens it's so awesome I'm gonna sell all my Pentax gear"?
04-18-2014, 02:02 PM   #206
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QuoteOriginally posted by dtmateojr Quote
"THIS is the one shot with a full frame with a less expensive lens
Fixed that for you.
04-18-2014, 02:04 PM   #207
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The saga continues. Check the comments at the bottom: http://drcameraphd.blogspot.com.au/2013/04/fitdoesntmatter.html?showComment=1397854121095
04-18-2014, 02:05 PM   #208
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QuoteOriginally posted by dtmateojr Quote
The saga continues. Check the comments at the bottom: Dr. Camera: F/it.doesnt.matter

You sound like a very angry person. What has this blogger done to upset you?
04-18-2014, 02:16 PM   #209
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QuoteOriginally posted by ElJamoquio Quote
You sound like a very angry person. What has this blogger done to upset you?
The blogger contradicted him with actual, accurate information. Bad guy



Above Jr. seems to be accepting that 50mm f/8 FF =~ 35mm f/5.6 aps-c from the same location, because it's the same AOV and scene luminance and linear aperture = 6.25mm, then radically changes the AOV in his next example (100mm vs 35mm!) and wonders why it can't be the same amount of total light projected onto the sensor even though it's the same linear aperture (6.25).

Oh, the troubles, the troubles...

Last edited by jsherman999; 04-18-2014 at 02:28 PM.
04-18-2014, 02:16 PM   #210
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QuoteOriginally posted by ElJamoquio Quote
You sound like a very angry person. What has this blogger done to upset you?

It's very difficult to assess emotion in the interwebs. I wasn't angry at all. Maybe it comes out that way but the truth is I'm laughing as I was typing my comments Until now he still can't tell me how he measured noise. I bet he just "normalized" them, i.e. downsampled (cheating)
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