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07-30-2014, 06:03 AM   #376
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QuoteOriginally posted by jppp Quote
I'd like to see similar framing with several formats using the same aperture, the same focal length (meaning that the camera would have to be placed closer to or further from the subject according to the format) and the same ISO. With a suitable subject, the differences or similarities would be easy to detect...
But what about lenses and their differences?

After all, the topic began with a video of a specific example, not from theoretical approaches!

07-30-2014, 06:32 AM   #377
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QuoteOriginally posted by Aksel Quote
But what about lenses and their differences?
This is exactly what I'm not interested in, the endless discussion about what's really different and what's really not. Equivalence is not necessarily being exactly the same. It's more like what's comparably similar. There's a huge difference, and this is probably one of the problems from which a lot of this topic gets its fuel. And that's why it's so tiresome. If the camera is of a different brand, sensor has a different MP count and size, lense is this or that, etc etc, that all makes finding exact matches impossible. It's all comparable, relative to something else, but in the end, the differences are there. Some cameras and some lenses are measurably better than others by various different parameters but that's not what I'm after right now.

As I said, I'm only interested in seeing two sets of side-by-side comparison shots taken of the same subject and silmilar framing:
- one with f2.8 glass and different sensor sizes, like FF, APS-C, M43, Q, whatever, all with the same aperture, focal length and ISO
- the other with the appropriate math to make the scenes identical regarding DOF and noise levels
The same framing, first with we are being told is equivalent regarding the crop factor, whatever that may be, and then using the math to make the same frame actually match in terms of DOF, bokeh and ISO. Tony had some comparisons, but I'd like to see more than two systems side-by-side.
07-30-2014, 07:05 AM   #378
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It isn't rocket science. If you take a FA 77 and shoot it at f2 and then at f2.8 (on any format), how much difference is there in depth of field? Clearly there is some difference, but is it enough to make or break a shot?

The problem, I guess, is primarily on the wide end, where there just aren't fast and wide options present in the Pentax universe. Sigma has a few options. I think they have a 20mm f1.8, but other than that, Pentax doesn't offer anything that is similar to a 30mm f1.4 on full frame. Whether or not you need that is a photographer specific question.
07-30-2014, 07:05 AM   #379
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QuoteOriginally posted by jppp Quote
I still fail to see the need to argue over this topic. It's just as futile as fighting over religion. Nothing good comes out of it.
"Equivalence" is a religion, i.e. "an organized collection of beliefs, cultural systems, and world views that relate humanity to an order of existence".
QuoteQuote:
Thou shall live according to:
  • Perspective
  • Framing
  • DOF, Diffraction, Total Amount of Light on the Sensor
  • Shutter Speed
  • Brightness
  • Display Dimensions
Blind are those who do not obey!


What you want to see can be observed in isolation, one thing at a time (which almost always leads to a better understanding). For example, you absolutely don't need "equivalence" to study perspective. Perspective depends only on the camera position and orientation in relation to the subject. It is not affected by the format.
So I wonder, which issue needs to be clarified?

07-30-2014, 07:11 AM   #380
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QuoteOriginally posted by jppp Quote
This is exactly what I'm not interested in, the endless discussion about what's really different and what's really not. Equivalence is not necessarily being exactly the same. It's more like what's comparably similar. There's a huge difference, and this is probably one of the problems from which a lot of this topic gets its fuel. And that's why it's so tiresome. If the camera is of a different brand, sensor has a different MP count and size, lense is this or that, etc etc, that all makes finding exact matches impossible. It's all comparable, relative to something else, but in the end, the differences are there. Some cameras and some lenses are measurably better than others by various different parameters but that's not what I'm after right now.

As I said, I'm only interested in seeing two sets of side-by-side comparison shots taken of the same subject and silmilar framing:
- one with f2.8 glass and different sensor sizes, like FF, APS-C, M43, Q, whatever, all with the same aperture, focal length and ISO
- the other with the appropriate math to make the scenes identical regarding DOF and noise levels
The same framing, first with we are being told is equivalent regarding the crop factor, whatever that may be, and then using the math to make the same frame actually match in terms of DOF, bokeh and ISO. Tony had some comparisons, but I'd like to see more than two systems side-by-side.
The most I've seen in the same comparison is FF vs. aps-c vs. m43 (I think.) Usually you see m43 vs. FF or FF vs. aps-c. I don't have any bookmarked, but the dpreview article has some specific examples and Tony's video (already cited) has a pretty nice overview. Some general googling will show you many more examples (you may need to do a little work yourself here )

There are a few things to consider regarding equivalence - it tells you what to expect with regard to certain parameters, but it can't tell you exactly what a certain combo will look like, because lenses will have their own characteristics outside of those used by equivalence, a sensor could have a certain noise profile that's 'different' than another even though the SNR may be similar, resolution isn't really accounted for (but it is affected by several of the same parameters,) etc. It was never claimed to tell all these things. Some folks fault equivalence for not being about to tell them everything, and throw it out as worthless, but its really quite valuable - pretty much essential if you're asking the types of questions you asked.

I have personal examples that show the FOV/DOF difference, but during those tests I wasn't trying to capture noise comparisons (which wouldn't have been a good fair 'equivalence' test anyway since the bodies I had didn't match sensors very well - the FF sensors were newer gen.)

---------- Post added 07-30-14 at 08:15 AM ----------

QuoteOriginally posted by Kunzite Quote
"Equivalence" is a religion, i.e. "an organized collection of beliefs, cultural systems, and world views that relate humanity to an order of existence".
Most religions don't have a rock-sound physical basis behind them as equivalence does, but you can carry on with your personal religious crusade against the 'abomination'

By the way, a fascinating read: link to a recent epic takedown of a science-denier. And part II, where the hapless denier comes back for more


.

Last edited by jsherman999; 07-30-2014 at 07:25 AM.
07-30-2014, 07:50 AM   #381
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QuoteOriginally posted by Rondec Quote
It isn't rocket science. If you take a FA 77 and shoot it at f2 and then at f2.8 (on any format), how much difference is there in depth of field? Clearly there is some difference, but is it enough to make or break a shot?

The problem, I guess, is primarily on the wide end, where there just aren't fast and wide options present in the Pentax universe. Sigma has a few options. I think they have a 20mm f1.8, but other than that, Pentax doesn't offer anything that is similar to a 30mm f1.4 on full frame. Whether or not you need that is a photographer specific question.
It doesnt make or break, but it does enhance it substantially. Why not stop there? Why not shoot portraits with a 50mm strictly at f/2.8 instead of f/1.4 or f/2?

2.8 is often good enough but the having the option of opening it more is usually better for the photographer.

Also it's not just about whether the subject isolation is enough or not, but also about flexibility. Either 28-75/2.8 or 70-200/2.8 on FF can both replace a 50mm/2 prime on APSC. On weddings instead of having 2 apsc bodies on 35mm/2 and 50mm/1.4, I can now have 2 full frame bodies with 28-75/2.8 and 70-200/2.8. Basically I gain wide and tele, at the cost of weight and the slightly less subject isolation with the 50mm prime. I can regain subject isolation (and top it) by switching the 70-200 to 85mm/1.8, or just by backing up a bit and use the 70-200 instead.

Contrary to popular belief, I actually dont find much value in FF on the wide end of things - unless you need the Canon tiltshift stuff.. Subject isolation is still relatively poor, and with good quality lenses APSC can deliver excellent performance on the wide end, without the crazy cost of FF wide glass and bigger filters. (I'm not a landscape photographer though, so take that with a grain of salt...)

Last edited by Andi Lo; 07-30-2014 at 08:03 AM.
07-30-2014, 08:25 AM   #382
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QuoteOriginally posted by Andi Lo Quote
It doesnt make or break, but it does enhance it substantially. Why not stop there? Why not shoot portraits with a 50mm strictly at f/2.8 instead of f/1.4 or f/2?

2.8 is often good enough but the having the option of opening it more is usually better for the photographer.

Also it's not just about whether the subject isolation is enough or not, but also about flexibility. Either 28-75/2.8 or 70-200/2.8 on FF can both replace a 50mm/2 prime on APSC. On weddings instead of having 2 apsc bodies on 35mm/2 and 50mm/1.4, I can now have 2 full frame bodies with 28-75/2.8 and 70-200/2.8. Basically I gain wide and tele, at the cost of weight and the slightly less subject isolation with the 50mm prime. I can regain subject isolation (and top it) by switching the 70-200 to 85mm/1.8, or just by backing up a bit and use the 70-200 instead.

Contrary to popular belief, I actually dont find much value in FF on the wide end of things - unless you need the Canon tiltshift stuff.. Subject isolation is still relatively poor, and with good quality lenses APSC can deliver excellent performance on the wide end, without the crazy cost of FF wide glass and bigger filters. (I'm not a landscape photographer though, so take that with a grain of salt...)
I do shoot portraits mostly at f2.8 (on APS-C). I like having some environmental presence in photos, not just a blurred background, although it is possible with longer lenses on all these formats.

(77 at f2.8)

07-30-2014, 09:01 AM   #383
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QuoteOriginally posted by jsherman999 Quote
Most religions don't have a rock-sound physical basis behind them as equivalence does, but you can carry on with your personal religious crusade against the 'abomination'
Most religions, and it's not as rock-sound as it seems (I'll remind you again about the diversity of "equivalences", Tony's video included - which has too much BS and too little science). And in regard to photography, I'm a pragmatist Of course, that's as good as "pagan" for some
You should think again who is crusading here, by the way

Accepting the usefulness of a theory according to which there's no advantage of going medium format compared to m4/3, offering as explanation a set of computed numbers when the result is obvious by simply looking at large, well-made prints for both formats - I won't do that.

Just curious, since the discussion started to be centered around samples made in certain predefined settings; there are some format switchers around (I'm one of them, of course). After the switch, do you try to use the new format cameras just as before, or perhaps you're adapting your technique in some ways? Did anything change?
I think this question is more important than "let's suppose we want to get the same dof, framing..." scenarios.

07-30-2014, 10:03 AM   #384
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QuoteOriginally posted by Kunzite Quote
After the switch, do you try to use the new format cameras just as before, or perhaps you're adapting your technique in some ways? Did anything change? I think this question is more important than "let's suppose we want to get the same dof, framing..." scenarios.
I think the answer to your questions are yes and yes. I am assuming that you're moving from a FF to APS-C here. One will find that as you use that 50mm the framing seems a bit off, at f2.8 or f4 the DoF is just not the way you like, you have to stop down a bit, pretty soon your once "OK" f2 glass is now not getting the type of shots that you want. You find that you get a slightly better shot with a 40mm or a 35mm the framing is a little bit better, just enough seems to be fitting in the frame, maybe you still need something just a tad bit wider but the 35mm will do the trick nicely indeed. Portraits that used to be shot at 135mm that keeps you out of the subjects personal space is just not happening any more something is off, you adjust and tweek until, wham! You find that the 100mm macro is suddenly doing regular double duty as a full portrait lens.
Of course I'm just a noob and my little history with FF has been with film quite some time ago so it was fairly easy for me to adjust. But this and listening to other photographers talk about this thing it seems that they were/are adjusting to get an equivalence, whether by name or by image. Photography is still an art and art has some very fluid and subjective criteria (filling the frame, DoF, rule of 3rds etc). Understanding equivalence IMHO gets one to experiment less in order to obtain the desired look form a shot that is (fairly) consistent with what is considered a good shot. And please, don't anyone say they don't care about what others think because that will label you as less than professional (or like most people just gearheads )
07-30-2014, 10:22 AM   #385
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I did move from "FF" (film) to APS-C, years ago; that was quite some change (which would break "equivalence" on several levels). I plan to move back, this time to digital FF, once the option is available from Pentax (I'd rather like it this way).
But this is not about me, I have my own answer; I want to know what is yours.
07-30-2014, 10:41 AM   #386
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I moved from FF to APS-C back to FF. Equivalence worked perfectly, but it never did buy me any pizza.
07-30-2014, 10:58 AM   #387
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QuoteOriginally posted by Kunzite Quote

Accepting the usefulness of a theory according to which there's no advantage of going medium format compared to m4/3,
Job #1 around here should to not misrepresent an argument to frame it in your favor. The question was never 'does MF provide advantage to m43', it was 'for noise only, does it vs. a FF combo El J had in mind' You then asked about a specific lens example (Nokton f/0.95) on micro-four-thirds which I tried in good faith to answer, which you didn't want to accept. C'mon, try to play nice.

.
QuoteQuote:
Just curious, since the discussion started to be centered around samples made in certain predefined settings; there are some format switchers around (I'm one of them, of course). After the switch, do you try to use the new format cameras just as before, or perhaps you're adapting your technique in some ways? Did anything change? .
One thing that changed for me - I often felt the need to shot my aps-c lenses wide-open a lot to get the subject isolation I wanted. Now, if I'm not light-constrained, I can stop down the FF combo to get a little better sharpness/contrast while retaining that same subject isolation for that FOV. If I *am* light constrained, I can shoot the FF combo at a larger aperture to get more light and there are surprisingly few times when that resulting reduced DOF ever has a negative effect on the image - it usually has a more pleasing effect. If it doesn't, if I absolutely need more DOF, I always have the option of stopping down to get back to the aps-c level output.

So what changed for me: more options, a few more capabilities. Not needing to 'take what I can get' quite as much.


.
07-30-2014, 10:59 AM   #388
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QuoteOriginally posted by ElJamoquio Quote
I moved from FF to APS-C back to FF. Equivalence worked perfectly, but it never did buy me any pizza.
The question was:
QuoteOriginally posted by Kunzite Quote
After the switch, do you try to use the new format cameras just as before, or perhaps you're adapting your technique in some ways? Did anything change?
So, what changed in your case? (please forget about "equivalence" for the next post, there's no point in stating once again that it's useful for you).

Last edited by Kunzite; 07-30-2014 at 11:13 AM.
07-30-2014, 11:01 AM   #389
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QuoteOriginally posted by ElJamoquio Quote
I moved from FF to APS-C back to FF. Equivalence worked perfectly, but it never did buy me any pizza.
If it can't order pizza, what possible good is it.

.
07-30-2014, 11:07 AM   #390
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QuoteOriginally posted by jsherman999 Quote
Job #1 around here should to not misrepresent an argument to frame it in your favor. The question was never 'does MF provide advantage to m43', it was 'for noise only, does it vs. a FF combo El J had in mind' You then asked about a specific lens example (Nokton f/0.95) on micro-four-thirds which I tried in good faith to answer, which you didn't want to accept. C'mon, try to play nice.
You don't get to decide what was the question
I constructed a plausible scenario in which "equivalence" fails, even if its conditions are met. I don't have to constrain myself within what ElJ or anyone else previously said. I don't have to "play nice" by always following the patterns set by "equivalence". Regarding your response, I don't have to accept that pre-computed SNR is an acceptable answer.

QuoteOriginally posted by jsherman999 Quote
One thing that changed for me - I often felt the need to shot my aps-c lenses wide-open a lot to get the subject isolation I wanted.
Thanks. So you're shooting at times with a shallower DOF. Anything else? You're using similar compositions? You're looking at the images the same way?
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