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06-20-2016, 12:45 AM   #121
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"f you [...] have equivalent apertures", and you should add "equivalent" ISO and the same shutter speed - this is exactly the idea that I'm challenging. You don't have to. I don't believe in a single exposure setting which would always be correct for a given photo.

06-20-2016, 01:03 AM   #122
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Equivalency is a prerequisite for comparability. You don't have to compare. But if you do, you should have equal expressions on each side of the equation.
06-20-2016, 04:00 AM   #123
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And once again, I disagree. That theory might be, or might not be a prerequisite - it all depends on what you're comparing.
Yet if you ask its advocates, they won't say anything other than repeating the conditions required by that theory. Are they even comparing something, or just supporting that theory?

You shouldn't assume that you can have "equal expressions on each side of the equation". You can't. You're talking about different formats, and - obviously - different cameras; they're not the same.
06-20-2016, 04:07 AM - 1 Like   #124
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QuoteOriginally posted by Kunzite Quote
"f you [...] have equivalent apertures", and you should add "equivalent" ISO and the same shutter speed - this is exactly the idea that I'm challenging. You don't have to. I don't believe in a single exposure setting which would always be correct for a given photo.
You are correct. 30mm f2 and iso 100 and 1/200 second on APS-C should be roughly equivalent to 45mm iso 200 and 1/200 second on full frame. People do tend to leave the iso out of the equation for some reason, but if you don't change it, then you won't get a correctly exposed image on one format or the other.

I guess I am more irritated by the whole "full frame doesn't have perspective distortion because it uses proper focal lengths, but APS-C does." If you use equivalent focal lengths and have similar framing, you really can't tell the difference (except that certain lenses do render differently).

06-20-2016, 04:24 AM   #125
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I would be irritated by that idea, too. Perspective depends on your station point (in relation to the subject), right? We don't need needlessly complicated theories for that, just understanding of the basic concepts.
06-20-2016, 04:42 AM - 1 Like   #126
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QuoteOriginally posted by Kunzite Quote
I would be irritated by that idea, too. Perspective depends on your station point (in relation to the subject), right? We don't need needlessly complicated theories for that, just understanding of the basic concepts.
Yes, equivalence is good for this too.

Capturing a images from the same spot pointed at the same spot with lenses using same FOV will capture equivalent frame regardless of sensor size. And if using same size on aperture, equivalent DOF will be captured. If also using the same shutter speed they will both capture equivalent noise levels if both images is captured with sensors of equivalent sensor tech.
06-20-2016, 05:35 AM   #127
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Pointless discussion, as usual. Why on Earth would I have to think about exposure and DOF when discussing perspective? Why on Earth should I think about imaginary "equivalent sensor tech" when perspective doesn't care about sensor technology at all?
I'm out. I can't change your way of thinking, anyway.
06-20-2016, 05:46 AM   #128
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QuoteOriginally posted by Kunzite Quote
I would be irritated by that idea, too. Perspective depends on your station point (in relation to the subject), right? We don't need needlessly complicated theories for that, just understanding of the basic concepts.
Maybe. But it is trotted out multiple times that a 55m on APS-C sucks for portraiture while an 85mm is awesome on full frame. The reality is (assuming the same quality lens) that you'll have a hard time telling them apart.

As to the rest of equivalence, I still find it pretty useless. The widest apertures on full frame lenses (the ones that prove that full frame is better) are pretty useless to me due to lack of depth of field. I like it. It has nice resolution and particularly with pixel shift, you can get pretty awesome images with amazing dynamic range. But a K3 is pretty sweet camera too and more than capable.

06-20-2016, 08:24 AM   #129
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QuoteOriginally posted by Rondec Quote
As to the rest of equivalence, I still find it pretty useless. The widest apertures on full frame lenses (the ones that prove that full frame is better) are pretty useless to me due to lack of depth of field. I like it. It has nice resolution and particularly with pixel shift, you can get pretty awesome images with amazing dynamic range. But a K3 is pretty sweet camera too and more than capable.
But the fun thing is that you know this because you are fully aware of the equivalence between these two formats, and are aware of difference in equivalence on available equipment on both formats.

Equivalence is just something that every experienced photographer is so used thinking about that they are not aware of using it.
06-20-2016, 09:17 AM   #130
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QuoteOriginally posted by Simen1 Quote
With comparatively low market share it doesn't make sense to have very many overlapping lenses. I don't see the need for the f/4 zoom line that Na Horuk mention unless it offers some other unique features.
While I doubt we'll see an f4 trio, that doesn't mean there isn't a need for alternatives to the existing f2.8 trio. We need a wide angle zoom with filter rings that costs significantly less than $1,500. And we probably need a lighter, less expensive alternative to the 70-200. What would make the most sense for Pentax, and probably could be done fairly easily, is introduce a DFA 18-35 f4-5.6 and a 70-300 f4-5.6. If those lenses featured comparable quality to the DFA 28-105, you could have a very solid variable aperture trio that was reasonably priced, much less heavy than the f2.8 zooms, and just as good, optically, as an f4 trio would likely be.
06-20-2016, 10:31 AM   #131
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Well let us wait till infos come out for this lens.
06-20-2016, 11:32 AM   #132
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About that perspective thing...there might be a point, But. I was shooting with my Samyang 14 on my K-3 and my Tokina at-x pro on my K-1. If I zoom tokina around 22 mm to get similar Fov I can relly already W/o PP see that lines are more straight with tokina, just because distortion is not as big as on wider lense. It looks about the same, but is not and if you have really well corrected lens for 20 mm, it will look more 'natural' tan lens with similar FoV on APS-C.

sometimes these things matter more, some times not at all.
06-20-2016, 12:30 PM   #133
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Is it possible they just patented this in case they ever want to build it, but without any immediate plans for doing so? I know some companies work like that; they patent everything that can be patented, to be on the safe side.

I mean, they also patented a stabilized AF sensor I think. That was something like 5 years ago. So far, they haven't implemented that either.

Last edited by starbase218; 06-20-2016 at 12:43 PM.
06-20-2016, 04:45 PM   #134
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You young whippersnappers with all your lens choices
We were lucky if a 28 joined the 50...and a 135 ? luxury
06-20-2016, 05:24 PM   #135
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Because I am an old guy I think in FF and translate on-the-fly to APSc. I never learned to think in APSc. For my K-3, which is now a light travel kit, I bought several second-hand DA primes (15, 21, 35, 70) from sellers preparing for K-1. On K-1 my existing FF lenses no longer require backward translation.

Either way, I just compose and expose to what I have with me, but it is more natural for me with my FF lenses on K-1.

Last edited by monochrome; 06-20-2016 at 05:33 PM.
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