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Forum: General Photography
02-02-2019, 11:01 AM
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Exactly the kind of misinformation I was talking about.
Only looking at a specific case. There are other cases where FF has the advantage. There are always trade offs, one format may be better in a given area, but that is not the same as one format is better than the other, just different. Equivalence doesn't prove one format is better, and it simply doesn't understand and doesn't predict what those advantages might be.
But we have seen many FF arguments where the argument is that FF is the best system overall because of the "physic" of equivalence and you can't argue with "physics" can you? I like APS-c for wildlife, I like FF for landscape, I like 1:1.2 for low light mushroom macros. Overall, one is not better than the others, they're just good for different things.
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Forum: General Photography
02-02-2019, 08:55 AM
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Is there a concise actual formula somewhere I wonder?
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Forum: General Photography
02-02-2019, 08:08 AM
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Is it just him or are there other people who have changed their position?
After all, inflexibility is only negative if you're wrong. :D
My biggest complaint with equivalence is it's less than 1% of what one needs to know in photgraphy, yet it can take up 38 pages of discussion. My point is it's minor thing that people spend way to much time thinking about.
This thread being case in point.
My estimation is that 95% of the people making claims based on equivalence are wrong. It has a really bad rep around here, to the point where I cringe when I see the word. Back in the old days I used to quote Falconeye, "Equivalence cannot be used to justify one format over another." (Rough paraphrase). Many discussions of equivalence would have stopped immediately if those words had been heeded.
It's only a rough guide for suggesting in which range within 10% or so you might look for a lens. And even then it has it's limitations. The fact that you can use a 1200 mm lens on APS_c doesn't man you can find an 1800mm lens for your full frame and use it the same way. It's beginner stuff. Same level as "Higher ISO produces more noise and loss of resolution." or "Stop down for more Depth of field" No one argues about those things. But they'll go one for 38 pages on equivalence. It's not that I hate equivalence. It's that it's talked about way more than it's worth. And many of us got along fine for years without it as formal concept. It's not essential information. It's not worth the time devoted to it, and it doesn't mean what a lot of people think it means. That's the issue.
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Forum: General Photography
01-31-2019, 08:19 AM
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If you're not exactly replicating an image, why do you need equivalence at all?
Talk to people who use the camera system he's buying would be the prudent thing. Say something really technical like "what do you use for portraits." Or look for a portrait lens in the manufacturer lens descriptions. Especially with a lens like an 85 1.4, there simply is no equivalent in a smaller system. You can match the focal length, but you can't match the subject isolation from 85mm and ƒ1.4.
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Forum: General Photography
01-31-2019, 07:32 AM
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Forum: General Photography
01-31-2019, 07:22 AM
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I have no problem with light source selection, people with different light set ups don't get in each others faces about it. The problem with equivalence is so many people get in your face with misconceptions. It's not the theory at issue here, it's the obnoxious people who try and use it to justify nonsense like total light, to promote one format over another, things for which it doesn't express an opinion. But some people think it does, and they'll tell you about it whether needed or not. It's a theory that has fallen into disrepute because of the ignorance of many of it's proponents. Maybe it's not fair, but, life isn't fair.
It got to the point where any discussion of equivalence was an exercise on debating imagined corollaries that simply weren't true. It got t the point where many of us don't want to hear the term ever again. I'd rather discuss practical lens selection in a way not so prone to mis-understanding.
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Forum: General Photography
01-31-2019, 06:29 AM
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If you have a depth of field guides on your lenses this isn't even an issue.
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Forum: General Photography
01-30-2019, 06:53 PM
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Now you're just being mean to the equivalentists.
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Forum: General Photography
01-30-2019, 11:43 AM
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Why does the word nefarious always remind me of Rocky and Bullwinkle?
But I have to agree with the basic information.... "trial and error" is being used as if it's somehow less valuable.
Scientific formulations are not even considered science until they are backed up with empirical data.
In other words theory (in this case equivalence" can only be substantiated through "trial and error". It might give bit of direction to your trial targets, but even that may prove unreliable in that you could be happy with a 40 on APS-c and unhappy with the only 60 you can find on FF. Equivalence does not reduce the need for trial and error, and it could save you time in that you know where to look, but it could cost you time in that what you find in that focal length doesn't create the look you want.
Anyone claiming you can do the theory without the empirical is selling you bill of goods.
After all the theoretcal constructs like equivalence you still have to go out and prove it with trials.
Given the difference in lens designs etc. it's pretty unlikely the suggestions provided by equivalence will lead to the best solutions to the problem.
After all, my FA 50 macro and the DFA* 50 1.4 produce very different results with the FA 50 macro being sharper edge to edge and the DFA 50 1.4 providing much smoother out of focus areas.
The FL is minor compared to the lens design.
Regardless of intent, one should not be intimating that equivalence will save time (that's not been proven), gives one a better understanding of different formats, that's also unsubstantiated, and it's limitations should be explained. It's not just equivalence at fault here. The only way to promote any shortcut, is to immediately point out it's limitations, especially for something like equivalence where all the claims made for it are debatable.
Most lens selections are made not using equivalence but by selecting something you might like from the categories. Ultra Wide angle, wide angle, standard, telephoto, aspherical, rectilinear, internal external focus, widest aperture and most important, what lens do you have now and why is it insufficient. Equivalence covers a little bit of that, but is in no way comprehensive, leaving us to debate over whether it actually saves any time or actually costs beginners time.
I personally wouldn't take anyone seriously one way or the other without some kind of hard evidence that what they say is true. Not even myself. Everything we have here about equivalence is that some people think it's a good thing, some people think it's misleading, and there's no actual evidence to say it's better or worse than any other method of picking out your next lens. In fact the only suggested use for it is is for the famous "beginner" shooting 2 formats (Is that even a thing.). Look at the criteria above and decide how useful it could possibly be. It just seems pretty insignificant to me. If others feel it's really important, that just means they approach things from a different mindset.
As long as you cover all the steps you need to in lens selection, spending the first 10 seconds of what should be hours of work determining which lens has the characteristics you want, the equivalence of the lens you want in a different format is probably neither here nor there.
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Forum: General Photography
01-30-2019, 07:52 AM
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Exactly. My basic zoom set up is two lenses, the 18-135 and either the 60-250 or 55-300 PLM. I have actually done tests, using the same lens on a K-5 and k-1, adjusting the focal length so I had the same framing for both images. I didn't need any theory at all, I just pick a few features I want to define the edges of the frame and frame as desired. Zooms make equivalence completely obsolete. And because my prime images are so often cropped, you have to be really lucky to find the exact framing you want with a prime, I generally get more resolution etc. with the zoom, because I crop to the framing I want, using the whole frame for the image. You could carry 20, 24, 31, 35, 40 50, 70 and 85 primes instead of a 16-85 and you'd still have times when you needed 45 mm, or 60mm, and waste sensor real estate going to the next lens down. I find with a good zoom, I rarely even come up with a number in my exif that corresponds to a prime, and almost never to a prime I actually have in my bag.
The big advantage to zooms is not that they can compete with primes, although my DA*60-250 certainly can. It's that in primes I have 50mm, 55mm and 70 mm. 3 focal lengths. With the 16-85 you have all the numbers in-between. If I can shoot the 16-85 at 80mm, when I would have had to go to 70mm using primes, I've saved myself 10% of the resolution by using a tighter frame. People buy new lenses for a 10% increase in resolution.
Just saying.
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Forum: General Photography
01-30-2019, 06:34 AM
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The crazy thing is Bill himself probably picked his focal length by trial and error, and just stuck with what worked. He spent a fraction of the time making this decision that has been wasted defending equivalence on the forum. There's something to be said for originality.
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Forum: General Photography
01-29-2019, 06:29 PM
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Ya, that's what I do. But, I've actually only compared one format with another, to settle arguments here on the forum. It's not the most productive of endeavours. :D
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Forum: General Photography
01-28-2019, 11:34 AM
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I used to have my students do narrow DOF subject isolation with point and shoots. If you can do it with a point and shoot you can do it with anything. :D
As well there are specific reasons to buy different formats.
For narrow DoF subject isolation. FF is the sweet spot. A 1.4 or 1.2 on FF is the ultimate. If you go one format up to MF you'll be shooting ƒ2.8 lenses and have more DoF if you go one format down to APS_c you lose one stop on the DoF scales ƒ1.4 is not ƒ2..
If you want everything in focus, cell phones are the way to go.
You have to do a lot of work with you equivalence formula to go through the DoF charts to come to that one pretty simple understanding, and the information isn't intuitive.
There are a lot of things you have to learn that equivalences is actually the long way around. Better to just ask someone who knows.
You could without direction print and understand the DoF charts along with the equivalence charts to come to the same conclusions, but talk about trial and error. That would be a humungous pile of work compared to asking someone who knows. Lets not pretend equivalence saves you experimentation. It might save you, it can also cost you.
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Forum: General Photography
01-28-2019, 10:09 AM
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Does someone actually do that? Lets not make up stuff. It skews the discussion with irrelevant information.
I will say, of the 12 or so assignments I used to hand out in a semester, one was to go thorough the photography yearbooks and collections of works by the masters, and come up with photograph they'd like to copy. SO, I'd analyze with them what the important points were and then have them do a photograph of their own where they demonstrate the use of the elements that made the image desirable to them.
I never felt it was important to do an exact copy. I felt it was important to understand the elements that made the image what it was, so you could incorporate them into their own work. Maybe trying for an exact copy could be part of that process, but during my time teaching I found no evidence of that. If anything, I found those students with the closest to an exact copy often had the least developed concept of what techniques were and how they could be employed. The geniuses were the ones that took the same concepts and turned them into something unique and original. I'm not convinced close to exact copies are ever more than time fillers. In fact I hated them. It means the kid watched my set up, and just copied it. The hot shots understood why I was doing what I was doing and were able to incorporate it into their own concepts without using the exact same setup and workflow.
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Forum: General Photography
01-28-2019, 08:07 AM
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Thanks, I had to think about this to understand what I was doing. There's a lot of things like this in photography where you do things unconsciously almost, and never give them a second thought. You do it, but you can't explain it.
And as long as it works for you, it's all good.
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Forum: General Photography
01-28-2019, 07:16 AM
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As I've pointed out many times, my DA*60-250 at 250mm is about the as FoV as my Vivtar 135 2.8. 8 feet from the camera. That was the only time in recent history I've been surprised by a lens.
My first look at any system is "what is considered a standard lens?" I Can work it all out from there. For an FF standard is about 50mm. 200mm is 4x, 24mm is .5x, for a 645 standard is 75mm 4x is 300 mm, 35mm is .5x. For APS_c standard is 35mm, 4 x is apron. 135, 18 is .5x. That's about as complicated as it needs to be. It doesn't matter what you do, lens characteristics, CA, distortion , resolution all have to be determined lens by lens. So that was the easy part.
I understand that some want to copy other's work. But I'd be sceptical that it couldn't be done using my method or any of the ways I'm sure other people have evolved for the process. My comment to "well I wanted to copy someone's work". is, there were other ways. Sure you used it, but that was a personal choice, it was far from a necessity.
Reminds me of a conversation I had about phone DoF guides. The person was actually getting out his phone to find out where the beginning and end of his DoF was. I looked down at the DoF guide and got exactly the same numbers he did. Similarly there's nothing wrong with the phone DoF thing, but if you think you're doing it for convenience or by necessity, your not. Taking a phone out of your pocket is not as easy as looking at the top of the lens.
But to summarize, there are other methods than equivalence to determine desired focal lengths. You don't need equivalence to get the job done. You can work without crop factor as well, but again it's a choice. Crop factor is much the same. It creates illusions that don't exist.
For a daylight image, a 20 MP 1 inch sensor is functionally the same as a 20 MP full frame image for most images.. Crop factor has nothing to do with it. A metric that disappears in some situations, (like the conditions most people shoot in most of the time) is not worth paying attention to. It only causes confusion. Almost always confusion where people think a 36x26 sensor will outperform their 1 inch sensor in all situations just because the FF sensor is larger.
And that is simply not true. And many who come to Full Frame are initially disappointed by how hard it gets to keep everything in focus in the larger formats. Everyone wants to say FF is better for low light and dynamic range, etc.
The corollary is small sensors are better for wide DoF, normal daylight shooting and are much more compact and portable. One should never say one without the other.
I really hate the illusions that you can get something, without giving up something. It's always a trade off.
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Forum: General Photography
01-27-2019, 04:13 PM
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I thought that was just Canadians. :D
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Forum: General Photography
01-27-2019, 02:16 PM
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True for the beginner who tackles multiple formats while in the beginning stage.
The concept of equivalence was established long before it was given a name. the 1.5 factor between APS-c and FF is useful because they use the same lenses. Going to 645 I don't care anymore. The lenses aren't interchangeable. I can't take the 55 from my 645, (wide angle) and put it on my K-1 or K-3. My XG-1 has FF equivalents right on the barrel.
However, the thing that gets forgotten, is that equivalence can't be used to compare camera systems. You can't look at equivalence and say FF is better or Micro 4/3 is better. That is a misuse of the concept, and that is why it's so hated. So many people try to use it to justify untrue assertions, and then when corrected claim science is on their side. Maybe it would be a bit harsh to say it's not for everyone, but, it's definitely been negative for me.
There's nothing more difficult to dislodge than an error caused by the inappropriate use of a scientific concept. Some people would defend the misuse of equivalence with their dying breath.
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Forum: General Photography
01-27-2019, 02:00 PM
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This would seem to be a topic that could go one forever....
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Forum: General Photography
01-27-2019, 11:22 AM
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Ditto....
I got through my first 50 years of photography without the theory of equivalence. IMHO it's added nothing to my understanding of photography. It's simply too simplistic to be of use. The factor it emphasizes, (focal length) is just to limited to be of much use.
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Forum: General Photography
01-27-2019, 11:02 AM
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How did you do with that? Jsherman once posted a 50mm FF images of his son riding his tricycle and one taken with a 35mm on APS-c. They were like two different pictures. I really think wide angle comparisons are the absolute worst for trying to make a case for equivalence, because wide angle lens characteristic and distortion make such a huge impact. If equivalence was going to be of use in copying images across formats, I'd suggest it would be a much more profitable undertaking in the telephoto end. The variability of the amount of distortion in various wide angles, just makes that a crap shoot. Those types of shots are where equivalence demising in utility as the amount of distortion correction varies considerably form lens to lens.
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Forum: General Photography
01-27-2019, 10:34 AM
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There's something I would never think of doing. When I copy someone's work, I'm copying the arrangement of compositional elements. What lens I'm using never comes into it. If a 70mm lens frames the scene the way I want it, I could care less what focal length I'm working with. To me the elements fo composition and design are worth copying, not so much the actual lens being used, unless like with a fisheye, the lens characteristics are part of the effect.
So, I'm totally opposed to the concept that in copying other's work, you should be using equivalence. You should be copying the compositional elements. Earlier this summer, I did some comparative images with my 50 macro, 70 macro and 100 macro. There were differences in the images, but not in how much I liked the images. Unless you are a shooting UWA the look doesn't change much.
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Forum: General Photography
01-27-2019, 09:55 AM
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Who does that. I go out with the camera I have, look through the viewfinder and compose. This sounds to me like an intellectual concept based on a real world situation, that in the real world never happens.
The only way I can possible imagine using this skill would be if you shoot in a small format to save carrying weight, and then go get your 4x5 view camera to give you a higher resolution image. But, I've never heard of anyone doing that.
If your premise is based on something people don't do, what use is it?
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Forum: General Photography
01-27-2019, 09:31 AM
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And I'm saying I have access to K-1 and K-5 files taken same location zoom lens and equivalent FL and I don't get cleaner more detailed images at any size I can verify.
The circumstances are tripod mounted, 2 second delay, no wind. Can't tell the difference.
Film was different, with film every image was enlarged. In digital most images are reduced. So, it's far from the same. My feeling, after actual experimentation is that by the time you've increased the image size large enough to see a difference you'll be standing so far away you won't see it anyway.
To print 300 DPI on K-3 you have to exceed 20 inches to start enlarging. On a K-1, 24 inches. But you won't see much difference even at those dimension. With professional enlargement software, I'm not convinced you'll ever see much difference.
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Forum: General Photography
01-27-2019, 07:52 AM
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Do you have examples, because I can post examples where K-1 and K-5 images are virtually identical. I'm not saying that theoretically you shouldn't get better images every time, I'm saying, I still need to see that in real world images.
Saying an image is better, until you can see it, it's meaningless.
And there seriously needs to be caveats applied. IN what circumstances does a K-1 provide better than K-3 images. I would limit that to low light /high DR images, which is a very small percentage of the images I shoot. Most of us reduce our images in size for display. And no one has ever been able to show that at the 3840x2560 of my 4k TV, a K-1 produces more resolution, or define where the magic point is that FF becomes better than APS-c, but my suspicion is it's around a 60 inch print. But I don't print 60 inches so even then I don't know.
To me, the circumstances in which a K-1 is better remains undefined. Shoot with my K-1 sometimes, I shoot with my K-3 sometimes, I shoot with my Q-S1 or XG-1 sometimes. I get images I like with all of them. And I get images I can't get with the others with all of them.
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