- July 14, 2017 at 9:29 am #24416
I realize I’m a bit late for tomorrow’s webinar, but I’ll put this in just in case or for a future time! 🙂
Would you have any advice on taking and exporting pictures for banners? Our family business is interested in the possibility of doing a full size banner (floor to top of divider) across the back of our booth at homeschool conventions. I’ve not done something like this before and welcome any suggestions! 🙂 Hope to take the pictures before the summer green disappears!
Excited to be back PRO!
MelanieJuly 14, 2017 at 2:02 pm #24428
I have never done super-large format printing before, but one thing I would immediately think of is how many dots per inch (dpi) your printing company does. My guess is probably 150 dpi. That means that an 8-foot tall banner would need a file that is 14,400 pixels tall! Of course, the banner may not go down to the floor, so maybe you don’t need it to be that big, but definitely make sure you are shooting at full resolution, or if you can, stitch a panorama for even greater resolution. (To give you an idea, the 18 megapixel Canon 7D’s files are 5,184 pixels wide by 3,456 pixels tall. That would be 36 dpi. The 50.6 MP 5DS has a resolution of 8688 x 5792, so just going out to buy a camera with more megapixels isn’t the answer… 🙂 )
I too am interested in seeing if anyone else has more suggestions, and whether anyone on these forums has done such large format printing before.July 14, 2017 at 3:26 pm #24439
Print resolution has everything to do with viewing distance. The further away the banner is, the lower resolution your print can be, and no one will be the wiser.
You can read all the gory details here: https://graphicdesign.stackexchange.com/q/487
Here’s the summary:
Distance Present Study 20 feet / 6 meters greater than 10 LPI 18 feet / 5.5 m 18.75 LPI or greater 16 feet / 4.9 m 18.75 LPI or greater 14 feet / 4.3 m 37.5 LPI or greater 12 feet / 3.7 m 37.5 LPI or greater 10 feet / 3 meters 50 LPI or greater 8 feet / 2.4 m 65 LPI or greater 6 feet / 1.8 m 85 LPI or greater 4 feet / 1.2 m 100 LPI or greater 2 feet / 0.6 m 133 LPI or greater 1 foot / 0.3 m 150 LPI or greater 6 inches / 15 cm 150 LPI or greater
Billboard printers must know that, how do you think they print photos on billboards without them looking “pixelated”?
EDIT:Looks like most billboards are printed at anywhere from 9-30 dpi. 🙂
Looks like anywhere from 120-75 dpi will work with a viewing distance of 10-14 feet. (Double the LPI to get the needed DPI.) Of course, whoever prints your banner for you will likely be able to tell you what resolutions they need to be able to print a certain size of graphic.
My printer can print up to 13×19 inches, which is well above my camera’s 16 “megapixels”. (13×19 @300dpi = 22 MP) You can look as closely as you want, but you can’t see any pixelation. I just printed some wedding photos at 13×19 with ~250 dpi, and the detail is simply amazing! And that’s at a 1 foot viewing distance. If you back off to 6 feet, you could get away with much less dpi.
Think about it, most computer screens are 72-96 ppi, and our pictures look just fine on them… (Of course with modern screens and FHD and UHD technology, I’m sure the ppi is going up) Some phones/tablets have ppi in the 200s.
July 15, 2017 at 10:59 am #24455
- This reply was modified 2 months, 1 week ago by Ezra Morley. Reason: add billboard details
Excited to be back PRO!
Yes, welcome back! I love your practical questions! Have you understood the answers so far?
I’ll do my best to provide a streamline answer to your question today during the webinar.
And just to clarify the graphic provided by @buddingphotographer, LPI (lines per inch) is not the same as DPI or PPI. You’ll need to multiply LPI by 2 (technically 2.2) to get the equivalent DPI.July 15, 2017 at 12:22 pm #24459
Thank-you so much for your input, @DavidFrazer, @buddingphotographer, and @jamesstaddon. It’s great to refresh my mind on PPI and add LPI to the mix! Unfortunately my brain isn’t remembering the difference/connection between DPI and PPI? Is one in-camera and the other for printing?:)
David Fraser’s comment on the 7D caught my attention – as I do have a Canon 7D! 🙂 (Not sure how many pixels it has and I’m away from my camera manual at the moment!) If I shoot an image at full resolution with that camera, will my only option be taking multiple pictures and ‘stitching’ them together, if I want a minimum viewing distance of say, two feet?July 15, 2017 at 12:58 pm #24460
The Canon 7D’s sensor is 5,184 × 3,456 (~18 MP). That’ll get you approximately 20 inches of print suitable for a viewing distance of 2 feet, (according to the chart above). If you want say, an 8 foot wide banner, you’ll need about 4 photos stitched to get the print quality that you want. I’m going to say that you’ll be fine with 150 DPI, which will give you about 30 inches of print per photo.
Again, I think your best bet is talk to the person in charge of printing, and ask them what their printer is capable of, and what DPI you need to aim for.July 18, 2017 at 2:36 pm #24510
Unfortunately my brain isn’t remembering the difference/connection between DPI and PPI? Is one in-camera and the other for printing?:)
That’s right! As so concisely explained by 99designs, “PPI describes the number of square pixels that show up in an inch of digital screen (usually between 67-300). DPI, on the other hand, is a printing term referring to the number of physical dots of ink in a printed document.”
If your printer prints at 300dpi and you set the resolution of your photo to 300ppi, then the on-screen pixels and the printed dots will equate to the same size. This article explains it well: https://99designs.com/blog/tips/ppi-vs-dpi-whats-the-difference/July 20, 2017 at 10:36 am #24628August 2, 2017 at 10:08 pm #24917
@buddingphotographer, I’m amazed at how much you know technically about photography! 🙂 Thanks for your input. This will be great to refer back to.
@jamesstaddon, thanks for the explanation of DPI and PPI! Makes sense! 🙂 And thanks so much for taking the time to mention it on the webinar. I’m excited to actually check it out tonight!August 9, 2017 at 11:02 am #24994
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