Feedback on my photography article series

Discussion in 'Digital Photography' started by ArtandStructure, Jul 1, 2009.

  1. ArtandStructure macrumors member

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    Klamath Falls, Oregon
    #1
    Hello all.


    I've begun a series of articles on my site intended to be a fairly straightforward introduction to, and practical explanation of, topics related to photography.

    The first article is regarding Megapixels as it is the single biggest feature people attach to. Naturally my second article will likely be something on lenses as the "zoom" is the next biggest spec people attach to, and so on and so forth.

    Feel free to have a look and comment if you think something should be clearer or should be included. Bear in mind this is an article on Megapixels, not Resolution. While the two are related, they are not the same and these articles are intended to be focused and cross-linked, not bogged down in extended discussions of other topics which should have their own article.
     
  2. ftaok macrumors 603

    ftaok

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    East Coast
    #2
    Jesse,

    I like the clean look of the site. Gives it a more polished look.

    As for the content, I agree that MP and zoom are the first two specs that typical buyers look for, but as you know, they can be misleading and/or irrelevant.

    For instance, as you've pointed out, the higher MP count doesn't necessarily translate to better pictures. Sometimes they come out worse regarding noise and artifacts.

    As for zoom, manufacturers are always touting the magnifcation number for their zooms. This number by itself is mostly useless. You need to know at least one end of the focal range. A 10x zoom doesn't necessarily mean that it's a telephoto lens. I would like manufacturers to start adding the 35mm equivalent focal range on their specs more consistently.

    As for future content, maybe an article on sensor size. Most people don't even know about this. The sensors on most P&S cams are ridiculously small. Which is how they get such huge zoom ranges with such tiny lenses. I would love it if manufacturers started putting the sensor size on their specs as well.

    Keep up the good work.

    ft
     
  3. dmmcintyre3 macrumors 68020

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    Mar 4, 2007
    #3
    Also, zoom on DSLR's works differently than on a PaS. The picture gets darker on the point and shoot as you zoom in. the DSLR it does not
     
  4. jackerin macrumors 6502a

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    Jun 29, 2008
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    Finland
    #4
    That statement sounds a bit weird by itself without an explanation. I'm guessing you're talking about the aperture decreasing at the tele-end..? (In which case it happens on almost all zoom-lenses.)
     
  5. fiercetiger224 macrumors 6502a

    Joined:
    Jan 27, 2004
    #5
    ...Obviously you haven't used a high quality lens before. :p

    If you get a higher quality (pro quality) lens, usually you'll have a constant aperture, meaning equal light gathering at all focal lengths. Most consumer lenses have crappy light gathering and ranged apertures at certain focal lengths.

    And actually, most point and shoots also have ranged apertures too, but if you're shooting auto, you won't ever notice that the picture gets "darker" at the higher focal lengths. You will however, notice that the image is noisier, since the camera has to raise ISO levels to balance out the lighting.
     
  6. ArtandStructure thread starter macrumors member

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    #6
    Thank you.

    I appreciate design restraint and fret over every detail from the navigation tree down to whether I should use a comma, semi-colon, ellipsis or nothing at all in a sentence.

    It is tempting to throw more technology at a site than needed, or bog it down with unnecessary gloss or candy just because it's easy to do. For instance, I've had the site for many years but have yet to use any Flash for several reasons.

    The entire site is barely over 10 megabytes, most of which is in audio files. I challenge myself to achieve the cleanest and most direct presentation with a look to satisfy my artistic interests and maintain an aesthetic energy/interest.

    Agreed. It is equally troublesome to explain to someone how a 6.2mm - 18.6mm lens on a point and shoot relates to an 18mm - 55mm DSLR lens, or even other point and shoots where the sensor size, and thus focal lengths, are not consistent.

    My own photos on the site give the focal length in terms of the crop sensor of my Nikons and I've thought many times over about including the 35mm equivalent as well but have not come to a clear decision on it without complicating or confusing things for the reader/viewer.

    I will come up with something in an article on lenses though. These articles are intended to be a start to finish overview of the topics in question. Obviously there is some basic material many people already know, such as what a megapixel is, but the article goes on to explain the implications of it for real-world/professional use and can be instructive even for advanced users. I try to cover both ends.

    I am writing these in part because it seems every article or explanation I've read on these topics is either one of, or some combination of:


    1. Too simple and incomplete

    2. Overcomplicated or confusing

    3. Strongly biased or misinformed

    4. Perhaps useful in the vacuum of a lab, but not realistic or practical from a real-world perspective


    Hopefully I keep a balanced formula on these.


    All the best,


    Jesse Widener
    Art and Structure
     
  7. BertyBoy macrumors 6502

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    Feb 1, 2009
    #7
    A very clean and professional looking site.

    iWeb or something else ?

    As a "straight-forward introduction", it's spot-on. I've kept a shortcut on my desktop, I'll check back from time to time.
     
  8. ArtandStructure thread starter macrumors member

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    Jan 14, 2008
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    Klamath Falls, Oregon
    #8
    Hand-coded HTML, PHP, CSS and maybe some Javascript using Taco HTML as an editor.

    I know, I know. Old school, but I am a bit OCD and don't like something else inserting whatever code it sees fit where I think it could be less bulky. I also compress my own images according a personal criteria to get what I feel is the best size/quality compromise. There are still people using dial-up, and my iPod Touch isn't nearly as fast as my desktop or laptop even with Wi-fi.

    I also work out exactly where I want the elements of the page layout positioned or aligned down to the last pixel to ensure the proportions and "feel" I am after.

    It isn't difficult to keep track of the code or update it. I could surely make it cleaner and more up to date with the latest and greatest standards/formatting, but the bulk of the site is content and design anyway, not code.

    Thank you.

    I don't know how often I will be able to add new articles. As you may have noted on the site I have an interest in and practice several arts and try to give the same attention to all. I hope to get myself on a regular schedule, perhaps starting by getting 1 article a month up until I see how my time goes.

    I've spent the last 4 months working on an iPhone/iPod Touch game which is nearly complete but has taken resources away from my other work in the meantime.

    I will try to post to the forums whenever I add a new photography article. In the meantime, enjoy, and certainly direct anyone to it who may have use for a primer.


    All the best,


    Jesse Widener
    Art and Structure
     
  9. ArtandStructure thread starter macrumors member

    Joined:
    Jan 14, 2008
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    Klamath Falls, Oregon
    #9
    Hello all.


    Just an update regarding the series of articles I am working on...

    I have been working on the next installment about lenses. It simply has been a tough process to decide what should or should not be included in the article to maintain completeness with simplicity.

    In the Megapixels article I opted to discuss resolution at another time as though the two are related they are not the same. Similarly, an article on lenses has many related topics which extend into other topics. For instance, I have to decide how much to talk about aperture as part of the lens without overextending it into exposure...for which I would have to talk about shutter speed and ISO to be complete, but which are not directly related to the lens.

    I hope to have the article out soon. This is an ongoing project and some articles may be slower in coming than others depending on their difficulty.


    All the best,

    Jesse Widener
    Art and Structure
     
  10. ArtandStructure thread starter macrumors member

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    #10
    Hello all,


    I am pleased to announce the completion of my new series of articles on lenses.

    While intended to be a single article in addition to the previous Megapixels article, this one quickly expanded into four separate articles by necessity:

    The Lens
    Wide & Telephoto
    Zooms & Primes
    and Aperture

    I think at this point, the articles could benefit from subheadings and cross-referenced links, but for now I want to just get it out, having been working on it for some time.

    Like the previous article, these are intended to be a broad, practical and straightforward look at these topics for the beginner and advanced user alike...and again these articles intend to remain focused on their subject, so while the article on megapixels does not go into resolution as they are not the same topic, I tried to keep lenses out of exposure, etc. though the choices were tough on some of the subject matter.

    As always, reactions, opinions, suggestions are welcome for discussion.


    All the best,


    Jesse Widener
    Art and Structure

    EDIT: After rereading this thread I am reminded I meant to make a brief mention that 3x, 5x or 10x as zoom indicators are relative to whatever focal lengths they encompass and not comparable without knowing the focal lengths involved. I will add this to the articles when I get the time.
     
  11. dazey macrumors 6502

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    Dec 9, 2005
    #11
    While this statement is correct, if you look at the optics of the lens I would put money on the fact that in its rawest form the optics of a constant aperture f2.8 lens will darken at the tele end. The lens just compensates for it presenting a constant aperture to the user. It is likely to be f2.8 at tele and capable of faster at the wide.
     
  12. AlaskaMoose macrumors 65816

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    Apr 26, 2008
    Location:
    Alaska
    #12
    I don't necessarily agree that camera manufacturers are using MP numbers as a sales gimmick. Well, some may be (maybe point- & shoot cameras, cell phones, etc.), but those who crop their images benefit from high MP counts. In my view, high MP sensor production will continue along high ISO noise reduction technology, and so smaller hard drives of larger capacity and speed. Perhaps a few of us don't ever print images larger than 8" x 10", but a lot do, specially advertising agencies that print murals and display images in giant screens.

    I am willing to bet that within 2-5 years the OP's article about MP will be obsolete.
     
  13. toxic macrumors 68000

    Joined:
    Nov 9, 2008
    #13
    first, Daniel Browning on the POTN forums dispels the myth that only a few megapixels are needed for a good print here: The understated utility of smaller pixels

    second, from a quick glance at your "Aperture" article, you need to get something clear: f-stop (f-ratio) is the ratio of the diaphragm opening to the focal length of the lens. The aperture of a lens is the size of the diaphragm opening, e.g. a 50mm lens at f/2 has an aperture of 25mm.

    edit - finished reading your other articles, so here are some other tips for you:

    from "The Lens":
    "There is also only so much a lens can do with regard to the laws of physics and as a result of these two factors, larger, interchangeable lenses (such as those used with SLR and some rangefinder cameras) tend to offer more options and greater quality on average than the smaller "do everything" lenses found in consumer point-and-shoot cameras. "

    I don't know if lens size has to do with anything...rangefinder lenses are much smaller than SLR lenses, and I don't think they lack in anything. two things you should think about and incorporate into this article:

    1. the shorter the focal length, the more difficult it is to create a lens that has uniform resolution and minimal aberrations across the entire frame. this is why wide-angles and ultra-wides are not held to the same optical standards as normal and telephoto lenses.
    2. sensor size. the larger the sensor, the less enlargement for the desired print size, which means there is less loss of resolution and less enlargement of any aberrations. in other words, smaller sensors require better lenses than larger sensors to achieve comparable image quality for the same print size.

    in your articles about the different types of lenses, I think you should make it clear that focal length does not inherently give a flatter or more exaggerated perspective. only the distance to the subject matters. Perspective Control in Images - Focal Length or Distance? (a tutorial).

    in "Zooms & Primes", I think you should mention that your focal length examples (14-24mm, 24-70mm, etc.) and their associated "type" (wide/standard/telephoto) are for 35mm/135 format.

    finally, a "normal" or "standard" lens is simply one that is has approximately the same focal length as the diagonal of the recording surface (so ~43mm for 35mm film). it just happens that a slightly longer focal length reproduces perspective similar to how we perceive it.

    other than that, good job.
     
  14. ArtandStructure thread starter macrumors member

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    #14
    That was a large part of the statement, that the bulk of camera users are consumers printing no larger than 8x10 and those consumer devices are marketed largely by megapixel, as a marketing tool along the lines of computer manufacturers pushing clock speeds. There were other caveats in the article regarding those who do print larger and the need for higher megapixel cameras. :)

    Again even a doubling of megapixels does not give that much more room to crop, and I can tell you from experience, the more you shoot professionally the more you find you have less time to tinker with photos which aren't "right" or "near right" out of the camera. If one finds themselves routinely needing to significantly crop photos, perhaps their process should be reconsidered because taking the time to correct what should be taken right in the first place (and let's be honest, one of the advantages of digital is the ability to shoot several variations at no real cost) or shooting at sizes twice what one really needs only "in case" they need to crop, and dealing with the resultant processing on such files is a wasteful approach to one's time and resources.

    Billboards, murals, movie posters, etc. are generally not shot significantly higher resolution than any other photo because they aren't intended to be view inches away. Take a close look at one of the 4 foot x 5 or 6 foot movie posters the next time you go to the movie theater. You may be surprised how low resolution these actually are.

    I am going to say it once here, then repeat myself a little further down ;) there is a difference between "in theory", "on paper", "technically" versus what is actually real-world practical. These articles are intended in part to avoid going into esoteric discussions which have 1% relevance and rather focus on a practical, real-world approach based on my current experience and understanding (which is always subject to change mind you). :)

    I promised I would repeat myself, but I will phrase it a bit differently. This series of articles is titled, "The Art of Photography". I am trying to give a broad overview of things with a practical bent rather than wallow around in technical esotericism which has little to no benefit in practical use. I am trying to give people an overview of the state of things without implying they should get wrapped up in, or invest in, how many megapixels their camera is, or how fast the continuous shooting rate is, because that is not photography. Too many people spend their time tinkering with their gear, waiting for the next best thing, or thinking if they can squeeze that extra percent of performance of theoretical quality out of their images, it will make their images better...

    ...and that is what we are talking about here, "theory". It is an interesting read "in theory", "on paper" and "technically", but the reality is the first several points of that post are moot (i.e. megapixels are already well beyond screen resolution concerns, etc.) and the latter points act as though there is nothing else involved in the camera system (the poster does remark there are other factors), as though magically increasing a sensor to the "ideal" 42 MP wouldn't outpace the resolving power of the lens (the poster would need essentially a "perfect" lens), the noise capability of the sensor (obviously there is debate on this), camera shake (none whatsoever would be required which is impractical), pixel "bleeding", whether it would really be any noticeably different than, say, 24 MP etc.

    EDIT: Here's a practical example. The post talks about how many megapixels would be needed to print 360ppi. Now, my distance vision is slightly blurry but my near vision is excellent. Several years ago I ran some print tests to see if I could notice significant differences between 240ppi and 300ppi as well as whether there was a noticeable difference between JPEG compression at "High" and "Normal" on Nikon cameras at the time. It turned out I could see a very slight difference...but only with the photo so close to my eye I had a hard time even focusing at that distance..a couple inches or less...I actually ended up damaging my eye slightly trying to discern these differences over the course of a few hours of test prints. I decided while I could see a very slight distance when focusing within an inch or two of the page, there was no practical difference from a regular viewing distance, and even then unless you had the same photo at both resolutions side by side and were specifically looking for the difference, it would be imperceptible...and that's with 240ppi, a full 33% less that the 360ppi the poster proposes. That's how silly the "theory" gets in all this. Who goes into a gallery and views photos from 2 inches away?

    Again the poster does mention there are other factors but you can't abstract one part of a system, talk about its theoretical maximum isolated from the rest of the system and present it as practical, because "practical" and "real" involves the rest of the system and the other detriments that such a thing would bring. In reality, might a 42 MP deliver better results than a 8 MP sensor? Sure, but not on any scale worth fussing about. Digital has a lower dynamic range than film, and yet we can easily take digital photos indistinguishable from film if we, as artists and masters of our tools (and any good artist can do great work with mediocre tools) know how to use them. I've seen any number of gorgeous "perfect", "professional" digital photos with todays tools and they would not benefit perceptibly from 3x the megapixels.

    Again, the point is to focus on the art and realize there is a diminishing point of return in that 1% of technical discussion, which do not produce results anywhere near the trouble to get there.

    Years ago when I was taking music theory, my classmates and peers wanted to sit around all day talking theory, comparing esoteric composers, etc. without actually composing. That is not "The Art of Music". There is a time and a place for it, but it quickly loses relevance if that is all one is doing with it. It isn't "practical" or "real". People in the arts town my photos are shown in, one of the top rated in the country, sit around in cafes discussing the wonders of art...of one photo or painting over another. Meanwhile I am out hiking in Glacier National Park and shooting. Which one is "The Art of Photography"?

    Yes but the 50mm lens at f/4 also has an aperture of 12.5mm. That was part of my point, that aperture is relative and the actual mm of the aperture is not important, rather the ratio to the focal length is. I was expressing aperture differently, i.e. instead of saying Density = Mass / Volume, I was rewording it as Volume = Mass / Density, which is the same thing. The aperture is, as you say, the size of the diaphragm opening, and because an f-stop is a ratio of that opening to the length of the focal length, an f-stop naturally implies an aperture. I don't know if I am explaining that clearly.

    Let me try a slightly different approach, again I am writing these articles with regard to practical understanding, for practical shooting, for practical practice of the art of photography, not merely discussing photography, so when we talk aperture, we have no practical concern for the actual measured mm dimension of the aperture. It is inconsequential to our work. What we care about are the effects of aperture and to achieve those effects and understand aperture, we need only to understand the relative ratio of the aperture to focal length, the f-stop, and that ratio itself is an aperture in the sense that an f-stop of f/2 on a 50mm lens is an aperture...an aperture of 25mm, but that last bit we aren't concerned about.

    Perhaps I should redirect the article to an emphasis on the word "f-stop" rather than aperture. I will have a look at it. I am bound to write things which stray from the conventional way of viewing things and some people aren't going to like it. For instance, I referred to the difference in sensor sizes as relative to the camera's optical system rather than the common analogy of smaller sensors being equivalent to what "full frame" would "see" if "cropped" because that verbage is flawed.


    All the best,


    Jesse Widener
    Art and Structure
     
  15. ArtandStructure thread starter macrumors member

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    Klamath Falls, Oregon
    #15
    Absolutely agreed. I will look at how I might incorporate this into the article.

    I am running out the door but will look into this. Thanks.

    I mentioned it in "Wide & Telephoto" when discussing sensor sizes, and said all photos in the articles were at equivalents, but perhaps I should note that in each article?

    Actually if I understand correctly, a "normal" lens is one which produces the expected perspective on a 2 dimensional surface when viewed at an expected viewing distance, because obviously the "natural effect" of that perspective will cease being natural when it falls out of order with the expected perspective at that distance i.e. it just so happens photos are expected to be viewed at a distance roughly 1:1 with the diagonal dimension of the image, so in 35mm still images, the diagonal is 43mm, and thus a roughly 43mm lens would produce expected "normal" images. However, in motion film (movies) the audience is expected to be positioned about 1.5 times the distance of the diagonal of the picture and therefore a "normal" lens for movies would be a longer focal length. I will review this.

    Thank you for your suggestions.


    All the best,


    Jesse Widener
    Art and Structure
     
  16. DoFoT9 macrumors P6

    DoFoT9

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    Singapore
    #16
    hey there jesse.

    this website is something very rare! we dont often see in depth websites of this sort! im not a big camera 'person', but i found the megapixel article very easy to understand - so i have no gripes there, congrats on making it so easy to understand!

    i do have a few problems and they lie more with the aesthetics of the website. there is way way WAY too much white space! add a gradient or something please.

    the links are not clear enough, the only way to tell is to see that the colour of them is gray rather then black. many people will not recognise this, i hardly did.

    you probably should have a logo or something of that sort to show the user what webpage they are on.

    where are you hosting the server? here in australia the delay between clicking the page being loaded was pretty high, especially on the wedding photos etc where i was waiting +10/20/30seconds for the page to finish loading for not alot of content. i know the images are small (good on you for making thumbnails) but the lag time is just a bit too high.

    i dont mean to offend, just trying to help you improve the website :)

    edit: didnt realise i was downloading something when i was talking about the lag tests, i stopped the other download and the pages loaded much quicker! there was still a waiting period but nothing AS bad as before. sorry for that!
     
  17. carlgo macrumors 68000

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    #17
    Instead of technical talk about mps, dots and all that technical stuff, I would appreciate a test using carefully prepared prints judged by a panel of people. Have them judge prints from 6mp DX to 25mp FX, on prints from 4X6 to maybe 20X30.

    I am skeptical because we are also told that 35mm film holds all this information and is equal to 25-40 mps. I found out for myself that this isn't true at all. Makes me wonder about other claims based on specs and technical theory.

    People can't see the difference in even an 8X10? Anyone want to argue that they could match an 8X10 contact print? Of course not, that would be silly. Anyone could easily see the difference.

    It is easier for technically savvy people to just sit down and write this stuff than to gather up people, print examples and do all that hard work. And, some people just want to separate the technical and the art. That is fine, but that is an agenda. All this test would pertain to is simple sharpness, not whether one thinks it is important or not.
     
  18. AlaskaMoose macrumors 65816

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    Alaska
    #18
    The reason why I believe that larger-in relation to megapixel-sensors will continue being produced is because that's the way sensor technology is going. I a few years ago when Sony 2MP cameras were so neat and popular with consumers. Today, 20MP through 60MP sensors are being produced, and the trend will continue.

    This is a nice technical article relating to MP, and includes "printing" MP:
    http://www.cambridgeincolour.com/tutorials/digital-camera-pixel.htm
     
  19. ArtandStructure thread starter macrumors member

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    Klamath Falls, Oregon
    #19
    That's what everyone thought and said about processor clock speeds. A few years ago everyone was saying we'd be at least 5-6GHz now and looking to push into double digits, and yet it stopped!! Why? Because there are other factors involved in the "system", matters of practicality, and an equilibrium which occurs between the two.

    I believe "Megapixels" will generally end up the same way. Just as processors shifted gears to multiple processors, multiple cores, multi-threading, faster system buses, offloading to graphics CPUs, etc. I think we will see Megapixels top out and the focus will shift to the sensor technology rather than brute pixels, such as improving interpolation, aliasing, noise, dynamic range, etc.

    For the record, and going back to the notion of "on paper" versus reality and practicality, I think if you polled professional photographers (those shooting regularly and being paid for their work) you'd find none of these theoretical boundaries being on virtually all their wish lists. Again, what we have today can always be improved, but today's cameras are pretty phenomenal at this point.

    I think you'd find wish lists which consist of items such as improving menu systems, dedicated button for this or that (personal preference), smaller/lighter etc...i.e. things which actually have a noticeable, real and practical impact.


    All the best,
     
  20. ArtandStructure thread starter macrumors member

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    #20
    Thank you. I am glad it is effective. I am probably too wrapped up in it to know how a "fresh" reader interprets it. Thank you for reading.

    I am something of a minimalistic expressionist. The white space is an intentional part of the design. I do agree on the links. I do try to reevaluate the aesthetics of the site from time to time, but your input is appreciated and taken into account.

    I believe it is hosted in the US by iPower.com. I've never had any real trouble with them. I read your edit below saying you were downloading at the same time. Is it still sluggish? The images are probably 30-60k apiece. Obviously the site itself is next to nothing. It shouldn't take terribly long to load.

    No offense at all. All suggestions are welcome.


    All the best,
     
  21. JBmac macrumors member

    JBmac

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    #21

    I posted this link in another thread earlier today, but the information here at the link below helped me make a large decent print of 20 x 30 through iPhoto, that before I dropped the resolution, would not print higher than about 8 x 10. I was able to do this in a program called Doubletake, as I don't use Photoshop.

    http://www.westcoastimaging.com/wci/page/info/photoshoptip/tip25.html
     
  22. ArtandStructure thread starter macrumors member

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    Klamath Falls, Oregon
    #22
    The silliest part about the extremes of technical theory is that "perceived quality" is more important than "technical quality". For all the theorizing about how many megapixels it would take to print the maximum theoretical sharpness, if a photo taken with fewer megapixels has a greater "perceived sharpness", it wins the contest. This is something akin to what I was getting at when I said I've seen "perfect" beautiful digital photos which would not benefit from 3x the Megapixels, because increasing the "data" of those photos would not perceptably change the aesthetic perception of those photos.

    I am happy for the discussion though. I hope people find all this informative on or from either side of the fence, whichever we choose.


    All the best,
     
  23. AlaskaMoose macrumors 65816

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    Apr 26, 2008
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    Alaska
    #23
    It's possible that somewhere along the line processor manufacturers will stop, but I doubt that's the case for the time being. Today's trend is to continue increasing sensor megapixel as you can see with the sensors being produced in Europe and Japan. Sony and others are already producing 50MP and larger sensors.
    http://www.adorama.com/MYDL33.html
    The same thing can be said about storage devices. I remember paying around $400.00 for a 45MB external hard drive fifteen to twenty years ago. Look at the hard drives of today.

    Technology is moving so fast ahead that just about any electronic product purchased today is pretty much old technology a very few years later.
     
  24. ArtandStructure thread starter macrumors member

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    #24
    I have read the article now and I think the methodology is extremely dubious and flawed.

    The assumption about perspective the poster is making (and I am not sure I agree, but we'll go with it for now) is:

    So we are going to objectively compare the size relationships in images...but the first step is to crop the images and change the size relationships to the images themselves so they match? This is the dubious part.

    EDITED to provide a hopefully clearer explanation...

    Perspective is a function of viewpoint (the viewing distance), angle of view (up, down, left, right), field of view (which is inherently tied to focal length and listed in lens specifications per focal length for this very reason, and thus why changing focal length is changing perspective), and viewport (the "frame" we are looking through, or image size).

    By cropping the image (changing the viewport), and then scaling it to compare to a differently cropped image at the same size, the poster is also changing the perceived viewpoint which makes up the composition (the viewing distance which he contends is the only factor in perspective) and by doing so he also changes the perceived focal length...to match the focal length he's trying to prove is the same...so naturally it will be. ;) Inadvertently the necessity of making this change in order to prove the point is an unintended admission that the perspective does not match and needs to be altered in order to do so.

    As the two sets of unaltered photos at the bottom of my Wide & Telephoto article clearly show, different focal lengths certainly produce different perspectives in the images they capture whether shot from the same vantage point, or shot such that the main subject is the same size in each photo.

    The poster contends photographers "think" they are choosing a focal length for a particular perspective but are actually just choosing a focal length which will capture the image at the distance they are choosing. In reality, going back to field of view, photographers are choosing a field of view that will capture the image at the distance they choose to shoot from. Field of view and perspective are inseparable with regard to a fixed frame size (the image size). Changing the field of view in a fixed frame changes perspective, so photographers are most certainly choosing a particular perspective with a field of view to fit within the fixed frame size they are shooting.

    There is no way to shoot a 3 dimensional scene with two different focal lengths and produce the same image (unless two cameras with different sensor sizes are used, but that would not be a clean or "controlled" compare), without altering it, regardless of what distance one is shooting from. Why? Because different focal lengths have different perspectives/fields of view in a fixed frame.

    So to recap, focal length does inherently give a flatter or more exaggerated perspective, and the distance to the subject is not the only factor which matters. This is good stuff folks. Keep it coming. It helps to organize my thoughts for future revisions. Many thanks.

    If I had any advice to offer the poster I would simply suggest to refrain from making, perhaps unintentional, comments that photographers...

    ...and with regard to their understanding of certain photographic effects, those...

    It's very bold and not always true. :)

    Oh, and to everyone, don't believe everything you read. Yes I know it goes both ways. ;)


    EDIT: see above



    All the best,
     
  25. ArtandStructure thread starter macrumors member

    Joined:
    Jan 14, 2008
    Location:
    Klamath Falls, Oregon
    #25
    Bear in mind the trend is nowhere near those kinds of resolutions for crop sensor, or even full frame cameras. The link you posted is for a medium format camera. The sensor's physical size has roughly 4.5 times the surface area of a crop sensor. By pixel density, it is equivalent to a 7-8 megapixel crop sensor (less than my D90), which only reaffirms my point that megapixels have a limit to their practical consideration.

    As far as continuing storage increases go, that isn't directly comparable. There is always "more" to store. There is hardly any limit to the number of things we would want to store electronically, but a camera doesn't exist in a purely electronic world. At the very least there are physical limitations to how much a lens can even resolve on some hyper-megapixel sensor, and also physical limitations to what we can even "see". Electronic advancement won't magically break the laws of physics in terms of the glass in lenses or our visual system.


    All the best,
     

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