6, 10, 18 MP. How big can you blow up a pic with any of these resolutions ??

Discussion in 'Digital Photography' started by igmolinav, Mar 28, 2010.

  1. igmolinav macrumors 65816

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    #1
    Hi,

    I currently own a 6 megapixel camera. I may buy a 10 or 18 MP camera. I just wonder how much I can blow up a picture with each of these resolutions. (Supposing I take the picture in RAW format).

    Thank you very, kind regards,

    igmolinav.
     
  2. HBOC macrumors 68020

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    #2
    the more MP, the better for large (feet by feet) prints. I have printed wonderful 8x10s with a 6MP camera.

    I think a 10MP can print 10x13 easily and maybe can even do a 20x30. It probably also depends on the glass, the printer and settings you shoot with. If you are going to be enlarging large all the time or quite often, a 5D would be better i think.
     
  3. Ruahrc macrumors 65816

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    #3
    Well you can blow up any picture to any size. I've seen billboards with 12MP pictures on them.

    Obviously, the larger you blow up the lower the resolution. How much detail do you want to keep? If you want to maintain nose-to-the-glass fine-art level of detail then you will not be able to enlarge as much as if you want a picture that looks great at a few feet viewing distance. Do you print with inkjets (your own or outsourced) or do you print with an optical printing process (like a Walmart or WHCC)

    It may be better to ask, I want to make X by Y prints, can I do that with my current camera, or do I need a new one and how many MP?

    Ruahrc
     
  4. toxic macrumors 68000

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    #4
    the theoretical maximum print size is found by dividing the dimensions (in pixels) by 200ppi (pixels per inch). however, it really isn't that simple. viewing distance means you don't need to maintain x ppi - a large print with very small dpi (dots per inch - dots on paper, pixels in a digital image) will look just fine because large prints aren't typically viewed very close.

    also, ppi doesn't tell you the resolution of the print in line pairs / mm, which can be more important than perceived sharpness (from adequate dpi).

    I think sensor size is more important than megapixels when it comes to large prints...but the best thing to do is to make your own prints and see how they turn out.
     
  5. igmolinav thread starter macrumors 65816

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    #5
    Hi,

    Thank you for your post. Good to know that I still can do 8x10 with the 6 MP camera. I have seen work in a gallery that was about 50x40 inches, (about 120 cm. x 100 cm.). How do people who exhibit work manage to get these sizes ?? What kind of digital camera are they using, or what process are they using ??

    Thank you again, kind regards,

    igmolinav.
     
  6. GoCubsGo macrumors Nehalem

    GoCubsGo

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    #6
    With a 6MP camera I have a 20x24 print on my wall that is very good. Under a 10x loupe, that's another horror story. If you're questioning a 8x10 print from a 6MP then I have to know what camera you're using.
     
  7. toxic macrumors 68000

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    #7
    they are either using medium format digital or large format film.
     
  8. igmolinav thread starter macrumors 65816

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    #8
    Hi,

    Thank you again for your posts : ) !!! I think I know what I'll do.

    Very kind regards,

    igmolinav.
     
  9. HBOC macrumors 68020

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    #9
    yes, those huge prints at the gallery were made from 40MP cameras. I think a 1DS3 could render results at that size.
     
  10. FrankieTDouglas macrumors 65816

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    #10

    Those 50x40 prints can be made with a DSLR. I've made similarly sized prints from my 5D, no problem.
     
  11. compuwar macrumors 601

    compuwar

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    #11
    Not always true- at the correct viewing distance and done with a good RIP, you can do that size just fine from almost any 6MP or better camera, though you'll get better results from ~12MP and up.

    Paul
     
  12. anubis macrumors 6502a

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    #12
    In general the human eye can resolve details that subtend one arcminute or .00029 radians.

    For something 12 inches away that corresponds to a spot subtending .0035 inches. So for example, if the sensor is 3000x4000, and the print size is 9x12 inches, then each pixel would correspond to a spot on the print .003 inches.

    This assumes perfect printing, perfect vision, and other nonsense. People blow things up much larger than that though, especially if the print is to be viewed on a gallery wall and people will be at least 3-4 feet away. You can use the one arcminute rule to determine how the print will look given a certain number of megapixels and the viewing distance.
     
  13. toxic macrumors 68000

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    #13
    well, if it's in a gallery I'm assuming they can be viewed relatively close. that usually means a large sensor.
     
  14. compuwar macrumors 601

    compuwar

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    #14
    Assuming is dangerous...

    There's a serious gallery near my northern location (NEPA) that sells *huge* prints, they've got one of the largest scanners on the East Coast of the US where they'll do full-sized scans of paintings for artists.

    Many of their ultra-large wildlife prints were done from cameras like the 1Dmk2 (8MP) and they looked just fine up close to me the one time I visited (eventually, I'm hoping to get displayed there- I'd love to sell a couple of $8000 prints!) I'm picky too- so when I say they looked just fine to me, I mean it.

    Paul
     
  15. Grimace, Mar 28, 2010
    Last edited by a moderator: Jul 27, 2012

    Grimace macrumors 68040

    Grimace

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    #15
    To reiterate an important point -- pixelation comes from distance. From further away, it's harder to see pixelation.

    From the video realm, think about a 1080p image on a 42" tv -- very crisp! Take the same 1080p image and put it onto a projector (and 8 foot screen), but then sit your chair back much further. At the right distance, you won't be able to see that the pixels any more -- but you can walk up next to the screen and see them!

    Same deal in a photograph or painting. Take this famous painting, which is a series of very small dots when you look closely. Step back 10 feet, and it is a unified whole. Is it pixelated? Yes/No - depending on your distance and perspective.

    [​IMG]
     
  16. toxic macrumors 68000

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    #16
    huh, that's interesting. thanks for pointing that out.
     
  17. AndyGordon macrumors newbie

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    #17
    On a more practical note I have printed very good images to A3 using Epson printers from 6mp (EOS 10D), 10mp (EOS 40D), 12mp 4/3 (Oly E-P1) and 12mp (EOS 5D full frame) and to be honest, when you show these pictures to people they honestly could not tell which image was from which camera.

    So, in practical day to day use, any will go to A3 quite comfortably. It is really only when you want to crop a small part of an image and print to A3 for example that more megapixels may be better, but that also depends on other factors such as quality of lens, pixel density on the sensor etc.

    But, with your 6mp camera as another poster suggested - give it a try, you may be pleasantly surprised.

    You may also want to look at ppi (pixels per inch) when printing. The perceived wisdom is that you should print at 300ppi from your image for best results - this is based I seem to recall on requirement for magazine reproduction.

    To determine therefore how big an image can be printed at that resolution divide the number of pixels on the length and width of the image by 300. For example, the Oly E-P1 image file is 4000 x 3000 pixels which at 300pi would give an image size of 13.33" x 10" and at 200 ppi 20" x 15"

    Hope that helps

    Andy
     
  18. OreoCookie macrumors 68030

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    #18
    You can blow up a 6 MP image to the same size as an 18 MP image. Also, in all likelihood, you have the wrong impression on how these things work.

    Dividing pixels by resolution is quite pointless: the resolution you need depends on so many different factors that it's impossible to give just one rule you should stick to. There are a few guidelines in my opinion:
    (1) If the picture is very good, very few people will criticize that the `resolution is too low.' Never happened to me. I've had 4 MP blown up to 45x30 cm^2, 16 MP to 90x60 cm^2, etc.
    If you are a commercial photographer, this may be important, but from the looks of it, you're not.
    (2) The size of the print depends most importantly on the content. This is just a gut feeling thing: some photos need to be printed big while others don't have to be or shouldn't. Since it is a matter of taste, there are no rules, do as you like.
    (3) Some pictures are grainy or benefit from having grain added to them. The 16 MP image, for instance, was a professional scan of a BW negative. The scan was so good, it captured the grain of the film.*
    (4) The texture of the material you print on is crucial: if you are printing on canvas, for instance, you don't need as much resolution: the material is rather rough, 75 dpi is probably plenty for this material. On the opposite end of the spectrum is glossy photo paper. The choice of material to print on depends on your taste and your photo.
    (5) The larger a print, the larger the viewing distance. Hence, you don't necessarily need more resolution if you have bigger prints.

    Currently, ~12 MP seems to be the sweet spot of APS-C-sized sensors. If you want to use the extra resolution of an 18 MP sensor, you need good lenses. If you think of buying a camera with a kit lens, I say forget about it. Also, image size scales as the square root of the megapixels: even though an 18 MP camera has 50 % more pixel, it allows you to print images 22 % larger on each side (at the same resolution). Even doubling the pixel count from 6 MP to 12 MP allows you to have ~40 % larger prints.


    * Even though it was an ISO 125 film, it was very grainy. The amount of grain also depends on the way the film was developed, for instance.
     
  19. CrackedButter macrumors 68040

    CrackedButter

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    #19
    Just to confer with OreoCookie, by accident I was in Paris in 2007 and did some street photography. I made an image and afterwards realised i had the camera set on a third of a megapixel, i managed to make a 4x6 print out of it and nobody complained about the slight pixelation and I do mean slight. This was on flickr no problem and it was exhibited, granted it was small and people had to look close because of its size but again, nobody said anything.
     
  20. funkboy macrumors regular

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    #20
    Back when I was shooting with a 10D, the 6MP image gave me about an extra centimeter on either side of an A4 sheet at the native 240dpi resolution of my Epson R800. They were really well matched for eachother.

    I've had a 40D for the last 2 1/2 years and the 10MP resolution is pretty close to that of an A3 sheet at 240dpi (though I don't own an A3 printer yet...). Back when I was developing my workflow I read that it was better to scale the output to the printer's native input resolution so that there's just that much less image manipulation that it has to do & you can control the quality & type of scaling that's done rather than have the printer just do something automatically without knowing exactly it's doing (kind of the same story as for color management, really).

    If you need to go bigger than native resolution, between what I've seen & the printing I've done myself I'd say as a very general rule that you can get a clean resize up to about 1.5x with the algorithms built in to Photoshop and proper sharpening, and if you need 2x or more you should be using something like Genunie Fractals, but then I haven't needed to do much resizing beyond about 1.5x so I can't really comment authoritatively on that.
     
  21. Doylem macrumors 68040

    Doylem

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    #21
    Just to add my two-pennorth... As well as the megapixel count, there's 'perceived sharpness'. Simply, a pic that's well-lit, with good contrast and definition, plus an interesting subject will tend to look sharp (even if it happens to be a bit soft at 100%), because it ticks so many other boxes in terms of what an image should be.
     
  22. carlgo macrumors 68000

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    #22
    Its funny that sharpness and resolution are usually discussed in such subjective ways. Some say it is unimportant, even when vast fortunes have been spent trying to achieve sharpness perfection. Others say "nobody complained" about their photos. Some merely say to step back and look at it that way.

    Everyone should try to go see some contact prints someday. They are pretty rare and really need to be seen in person rather than on a monitor. You can also see them in publications catering to large format photographers (if those publications still exist), and in some galleries now and then.

    The last ones I saw were color separations and were shockingly sharp, a whole new world to me. Vastly sharper than what most of us see today. Of course there are other advantages in big film, tonality and all sorts of things I am not an expert in, but they certainly are visible.

    After that, while I like some of my photos, they all seem pretty tame in comparison. Maybe I need to get an 11X14 view camera and some porters...
     
  23. G.T. macrumors 6502a

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  24. Chip NoVaMac, Mar 29, 2010
    Last edited by a moderator: Jul 27, 2012

    Chip NoVaMac macrumors G3

    Chip NoVaMac

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    #24
    Great example!

    Don't forget that that if you use Adobe Camera Raw or Genuine Fractals, you can up-rez the picture to larger sizes. I have a couple good looking 13x19's from a 10mp from a Panasonic LX-2.
     
  25. Gold89 macrumors 6502

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