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What camera do I need to shoot a large poster?


Steve_S Plus
14 183 3 United Kingdom
12 Nov 2013 7:41PM

Quote:Thank you Steve_S. This is the answer that I was looking for.

The photographer did know exactly what the photoshoot was all about. Out of 250 photos only 1 photo was chosen for a poster. The poster does not look sharp. Photographer provided photo sized at 3387x 5086 200dpi in tiff format. He said that that was the best he could do. It does sound like he made a mistake and set up his camera for a magazine photoshoot instead of a poster.



Its not how he set up the camera, its what he did with the file afterwards. Your file will print fine as a poster at 43cm x 64.5cm.........but that is smaller than you required Sad
Dann 7 250
12 Nov 2013 8:11PM
I have a 4ft x 3ft high-quality poster print of a Porsche NSF headlight assy - that was used as a front cover on a magazine - shot on a 6Mpx D70.
Jestertheclown 12 8.3k 253 England
12 Nov 2013 8:52PM
DPI and PPI are completely different things.
PPI, pixels per inch, is a measurement of length along the edge of your image and relates to the way you see it on your monitor.
DPI, or more correctly, dots per square inch, is a measurement of area and relates to placing ink upon paper.
And if you were able to count the number that are actually used, it wouldn't be measured in hundreds.
ianrobinson 10 1.2k 8 United Kingdom
12 Nov 2013 11:10PM
The canon 5d is a very capable camera indeed, i suggest as most have already you look at your photographer not the Camera.
I have produced images for my mercedes long wheel based van and they look great.

sv3a9523.jpg


not the best photo in the world but i was taking a shot of my sailing kayak, the van to the left has images of mine of kitchens we make, all done with the 5d mk ii.
none of them are grainy i may add.
Steve_S Plus
14 183 3 United Kingdom
12 Nov 2013 11:39PM

Quote:
DPI, or more correctly, dots per square inch, is a measurement of area and relates to placing ink upon paper.



DPI is NOT dots per square inch. 300 DPI according to you would be approximately 17 print dots x 17 print dots per square inch.

If you were to print an image at 300dpi it would have 300 x 300 dots per square inch= 90,000 dots per square inch.

PPI is a measure of input, DPI is a measure of output for the printer. Printers need to print at a higher resolution to reproduce what you see on screen. An image on epz, say 1000 x 800 ppi will display at a physical size dependant on your monitor. (E.g. if your monitor was 1920 x 1080, the image, at full size will take up 1000 x 800 pixels of your display.On a rather old 1024 x 768 monitor it will more than fill the screen. It doesn't matter what resolution you stipulate, its just pixels).

If I want to print the image (1000 x 800 pixels) at 300 dpi to get a decent print I will get a print 3.33 inches x 2.66 inches.If I tell my printer to print a 10 x 8 inch print from this file (like the original poster) it will look awful because the printer will be printing at only 100 dpi.

So if I need a print sized 16 x 12 inches my file needs to be 4800 x 3600 pixels. If the original file from the camera can give this resolution you don't need to worry. If you need to crop the original image and cannot maintain 300 dpi, your software has to 'make' up pixels to maintain 300dpi. If your crop is not too severe all will be OK. If your crop is severe, the made up pixels will show as a rather miserable print.
Jestertheclown 12 8.3k 253 England
13 Nov 2013 7:22AM

Quote:300 DPI according to you would be approximately 17 print dots x 17 print dots per square inch.

You're still using DPI as a measurement of length, which, correctly, it isn't. You can save your image on your computer at any DPI you like. It won't affect the actual number of dots placed upon the paper; a number which I imagine must be incalculable in practical terms.
The term DPI is misconstrued by photographers the world over and seems to have taken on its own meaning in photographic circles.
discreetphoton Plus
15 3.5k 20 United Kingdom
13 Nov 2013 8:59AM
The photographer has taken the photograph at the largest setting possible with the camera. As long as it's sharp and taken in a skilful manner (you can't make a silk purse out of a sow's ear), that's his job done.
It's a sorry excuse for a printer that can't figure out the interpolation, which is a fundamental part of their job.
I refer to my earlier comment.
Take the image somewhere else and you'll probably get a different answer.
jakabout 16 1.7k 1 United Kingdom
13 Nov 2013 9:08AM
With a print that size you need to take into account viewing distance as well. You really do NOT need massively sized files to produce a good print. I've made massive prints from relatively small files and they come out spot on and sharp to boot. It depends almost entirely on how good the original file is and with Adobe upsizing or whatever other software method you use, you should end up with a great print, if the original file was quality to begin with.
Steve_S Plus
14 183 3 United Kingdom
13 Nov 2013 9:08AM
DPI is a measure of printer resolution, how many dots of ink it can produce per inch. A 300 DPI printer will spray 300 dots of ink along an inch of print or 90,000 dots per square inch. Most printers nowadays have a much higher resolution e.g. 600, 1200, 2400 DPI.

What I am saying is that the image file should have at least 300 ppi so that the printed photo does not look pixelated. Each of those pixels may have 2 (600 DPI), 4 (1200 DPI) or 8 (2400 DPI) dots of ink when printed. It depends on the resolution of the printer.

So for a 10 x 8 inch print, the file should be 3000 pixels x 2400 pixels. i.e. 300 ppi
Steve_S Plus
14 183 3 United Kingdom
13 Nov 2013 9:14AM

Quote:With a print that size you need to take into account viewing distance as well. You really do NOT need massively sized files to produce a good print.


True. A large poster is not really designed to be looked at from 6 inches away. That is why 150-200 ppi is perfectly adequate.
mikehit 11 8.0k 13 United Kingdom
13 Nov 2013 9:25AM

Quote:Thank you all. I understand that the photographer has made a mistake and not the print shop.


I wouldn't be so sure.
If the printer was given the high-resolution from the 5D, then ha the printer messed it up? I understand what you are saying about their experience in printing these things, but it is worth checking.
GlennH 15 1.9k 1 France
13 Nov 2013 9:45AM
The printer should be able to handle a 5D MK II file at native resolution - that's a strange twist in this tale. However, the photographer should have known that merely flicking the ppi around wasn't enough to make the file printable at poster size - that's either a misunderstanding or lack of knowledge on his/her part.
vicstone 6 5
13 Nov 2013 1:12PM
I did listen to Steve_S' advice and used interpolation software with bicubic sampling method to increase image size from what the photographer gave me
43.4 x 65.2 cm with 78 Pixels Per Unit (50 MB file), 3387 x 5086 pixels, 200 dpi to 115 x 172.7 cm.

As a result, the file size increased to 354 MB and the photo is very smooth without any pixelation. Here are the parameters of the new file that are slightly different:
116.5 x 174.9 cm with 77 Pixels Per Unit, 8970 x 13470 pixels, 198 dpi.

It is clearly the photographer's mistake since he should have used his photoshop to increase the image size. I wished I knew all that before I gave 50 MB file to the print shop.

This is the solution to my question.
GlennH 15 1.9k 1 France
13 Nov 2013 1:28PM
Something about this scenario doesn't add up - a lab that knocks out most of Bangkok's advertising posters is incapable of upsizing a file?

David's (discreetphoton) remark is very apposite. The photographer should not really have been called upon to do this in the first place, though it shouldn't have been difficult.

Glad you've resolved it.
keithh 16 25.7k 33 Wallis And Futuna
13 Nov 2013 1:44PM
Doesnt add up just sums it up. The OP's solution and technical language dont match the initial tone and language base. ....but then I am professionally cynical. Wink

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