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Thread: Photo for 3.7m x 1.9m wall

  1. #1

    Default Photo for 3.7m x 1.9m wall

    Hi all,

    Apologies if a similar post is already present in the forum, however I couldn't find one.

    I have wall inside my house that is 3.7m x 1.9m and I want to replace the hideous leopard
    skin wallpaper with a photo like this one but I want to take it myself ...

    The front door of my house opens to the view of this wall so I'm after the visual impact
    from this distant (about 10m) rather than being able to view all the detail in the photo when standing right in front of it.
    I've been told that I will need to take the photo with a camera with at least 16 MP and in RAW format.
    Is this correct? Any other advise will be greatly appreciated!
    Last edited by V8Silverfox; 27th September 2010 at 08:28 AM.

  2. #2
    Join Date
    Feb 2010
    West / near Bukit Batok

    Default Re: Photo for 3.7m x 1.9m wall

    According to the rule of proportion, a 3.7m wide picture in 10m distance would be equivalent to a 14.8cm picture in 40cm distance.
    Why 40cm distance? Approximately the distance you use to view a regular picture.
    If you had 300dpi (which is a high resolution) on your picture, your 14.8cm picture would have 1748x897 pixel, which is less than 2 Megapixel.
    If your 3.7m image had 2 megapixel and you view it from 10m distance, it would appear similar to a 14.8cm picture viewed in a distance of 40cm.
    As such, Any camera would do, but the thing is: if you step closer, you will see the low resolution.
    So if you take a good image quality shot (e.g. with a cam that gives you 10MP), you may even want to 'resample' (note: not resize) this to a higher resolution before you go to print it. (You may want to resample this yourself rather than let the printer do it, so that you are in control of the resampling).
    A 10MP (3888 x 2592 cropped to 3888 x 1997) 3.7m picture will give you 2.67dpi (means 1 pixel is approximately 1 cm). So if you stand near, a pixel will be quite large, but already so much better than a 2 MP image. 'Resampling' is interpolating, meaning you make the pixel size smaller, maybe to 0.5cm. For that, you will need 7776 x 3993 pixel, which is 31 Megapixel.
    You would see that 16 MP would only give you a slightly smaller pixel size of 0.78 cm, and obviously only slightly better than 10 MP.
    RAW vs JPEG: Raw is uncompressed, will give you no compression artefacts, and also allows you to correct white balance. JPEG is compressed, and adjusting white balance will lead to further losses. RAW will give you certain advantage here.

  3. #3

    Default Re: Photo for 3.7m x 1.9m wall

    Works out about there.

    If you find a 300dpi print to be of good viewing quality at 1m viewing distance, you'd be happy with 30dpi at 10m. 30 dpi at your image size (146" x 75") is 4380 x 2250 pixels. Your aspect ratio is almost 2:1, while most DSLRs are 3:2, so you need a DSLR with 4380 x 2920 pixels, or ard 12.8MP. This doesn't take into account any cropping (other than to fit the aspect ratio), so 16MP or more would be a good idea.

    There are other sides to this though.
    300dpi at 1m or 30dpi at 10m is pretty high res, so in theory you could get away with less, say 100 dpi at 1m or 10dpi at 10m. This works out to just 1.5MP, but I'd advise against it (see next point).

    The other point is that although the image might look good at 10m, the pixelation at closer distances will probably look disturbing. I'd print at 100dpi, which works out to 142MP. Shooting that might not be practical, huh?
    I'd shoot at the highest practical resolution I can get (say 16MP), then upsample in Photoshop or better still, Print Pro, to 14600 x 7500 pixels (100dpi). Upsampling doesn't increase the amount of detail, but in blurs out the pixelation and jaggies, making the image more acceptable, IMHO.

    If you're wondering, I recently did a series of booth backdrops, banners etc for a trade fair recently, all upsampled to 100dpi from sources of varying quality. Each booth was 3m x 3m, and the biggest banner was over 10m wide. There were no complaints on the print quality -- jaggies and such.

    Before you go out and spend a few hundred dollars on printing, print a small sample, say A3 size section of the whole image (a part where there is relevant detail of course), put it on your wall and see how it looks.

    I assume you'll be having this printed on one of those plotter like colour printers (essentially giant inkjets). You'll need a semi-durable material, and probably some coatings for protection agaist water/damp, and maybe UV (if you have sunlight coming in, as you probably do). Your printer should be able to advise on this.

  4. #4
    Moderator ed9119's Avatar
    Join Date
    Mar 2002
    Blog Entries

    Default Re: Photo for 3.7m x 1.9m wall

    this wall is crying for a photo montage if its going to be near strong light , the colors might not hold up for too long....
    Last edited by ed9119; 27th September 2010 at 05:46 PM.
    shaddap and just shoot .... up close

  5. #5
    Join Date
    Feb 2009
    Singapore, East Sider

    Default Re: Photo for 3.7m x 1.9m wall

    I quite agree with the photo montage thing.

    Mmm... if you're up for the challenge, make a big picture out of many small pictures. =P

    it's done at quite a few places, but it's very very challenging to do in the first place.
    1 Camera Body and a couple lenses.

  6. #6

    Default Re: Photo for 3.7m x 1.9m wall

    Wow, thanks for all your help, it's really appreciated. I think I should post a picture of the wall
    and get your feedback? A photo montage sounds very interesting ...


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