Resolution for a 6'x4' canvas?

Soldato
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Hi guys.

I've had someone enquire about a large canvas of one of my photographs that I took ages ago with my 30D. (3504x2336, 72dpi)

They are after a canvas sized 6 feet wide x 4 feet high.

Is this going to be any good?

Cheers.
 
Not if you're viewing it at double the depth of your nose, but it will be fine if you're viewing it from where a 6x4ft canvas should be viewed. Can always use something like Genuine Fractals to interpolate up too, produces better enlargements than Photoshop :)
 
you're looking at ~ 16 A4 pages. Which is A0 I believe. If they want the print looking nice.. 300dpi+. I don't think your image will be big enough without pixalation.

You could raster the image, to turn it into a vector then enlarge it. But it will ruin most detail. Sometimes it's a nice finish, othertimes (when a picture is busy) it can just fail :)

I'm awful with images but they're my suggestions! :S
 
Thanks.

In their shop it's gonna be fairly out of the way anyway so no one will be viewing it up close.

I was going to send the images off to Intelligence Direct and they did a great job of the last canvas I ordered from them.

(This customer wants 3! :))
 
They are after a canvas sized 6 feet wide x 4 feet high.

Is this going to be any good?
Difficult to say without seeing the image in question. It could look anything from acceptable to awful, but you're really pushing things trying to go to above 2A0 from a 30D.

I was going to send the images off to Intelligence Direct and they did a great job of the last canvas I ordered from them.
Send the file off to ID and ask them for a 1:1 proof so you can gauge just how detailed the final result will be.

Defintely not especially as canvases generally look pretty awful anyway.
I think that's a matter of personal taste. I've seen some amazingly sharp and detailed canvas prints but it doesn't suit every image.
 
Good tip glitch. Thanks.

It might not be a problem actually as I may try and get some new photos for them. The photo is for a team in one of the BTCC support races and they are getting new cars for next season so I'm going to try and get some shots of their new cars for them :)
 
I've made a print at work that is hanging on my office wall that is 66"x44" (So 5'6" x 3'8") which was taken on my 12MP Nikon D300. It looks pretty damn good, but personally I think it is a teeny bit too big for the resolution.

Having said that, maximum print size depends on loads of factors; viewing distance, sharpness of shot, ISO used, how good your eyes are, etc etc.
 
take in mind that the canvas has a 'tooth' so it will hide a bit of pixelation, i do digital printing at work on canvs and 300 dpi is usually good but the higher the better lol
 
take in mind that the canvas has a 'tooth' so it will hide a bit of pixelation
That's a very good point.

When I used to do large-format canvas printing through ID I generally worked off a resolution equal to the tooth of the canvas in question for stuff that was stupidly big.

ID are pretty friendly and will happily send you some blank samples of the various media they print on if you ask nicely.
 
Send the file off to ID and ask them for a 1:1 proof so you can gauge just how detailed the final result will be.

It's not a terrible idea in theory but it rarely works well in practice IMO (If you've found it to be satisfactory fair enough!). If you look at say, an A4 1:1 proof of the size it will come out at the canvas, at the viewing distance for an A4 print it's going to look whack, but at the viewing distance for the whole 6x4 canvas you're probably not going to be able to make out enough from it to ascertain if it's any good or not.

OP: It doesn't have to be 300dpi to get a satisfactory print. FTR, I had an A0 print made of a shot I did with my Canon 20D yonks ago, and it was fine. That was an inkjet print too, so no canvas texture to help cover the lack of detail.
 
I've had someone enquire about a large canvas of one of my photographs that I took ages ago with my 30D. (3504x2336, 72dpi)

Sorry but I'm going to be the first to say... WTF...?

That 72dpi means absolutely nothing. Nada, zilch... :p

The resolution is a resolution but dpi is only when you say there are so many dots (pixels) within a certain size...

So you would print out at 6'x4' at ~50dpi with that resolution. If you printed at 3504x2336@72dpi you would end up with a print of ~4'x2.5'

72dpi is just an approximate pixel pitch of most monitors (at least I think that's where it originated, a 20" monitor will have approximately 100 dots per inch of horizontal screen space now). Even that doesn't really count as dpi is really only for printing.

(Sorry, not really relevant to the thread but this was the straw that broke the camels back so to speak, there are way too many people thinking sticking 72dpi in PS is going to do anything at all).
 
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It's not a terrible idea in theory but it rarely works well in practice IMO (If you've found it to be satisfactory fair enough!).
I think 'satisfactory' would be the key word here!

For the purposes it was used for, it worked well enough. I generally had a rough idea of viewing distance so I could mark up the entire canvas on a wall and get a selection of proofs from specific sections of the image in order to ascertain whether it worked at that size.

But given the quality of my work at the time and the customers that were buying it - it was far from professional and not something I'd readily choose to do again!
 
Lots of factors more important than pure resolution.

Noise, aberrations, focus, lens sharpness, exposure, etc.

It is probably required to use genuine fractal to enlarge. If you have a perfect 10-12 MP image that you can enlarge, and the viewing distance is reasonable, it might just work.

Tim
 
Sorry but I'm going to be the first to say... WTF...?

That 72dpi means absolutely nothing. Nada, zilch... :p

The resolution is a resolution but dpi is only when you say there are so many dots (pixels) within a certain size...

So you would print out at 6'x4' at ~50dpi with that resolution. If you printed at 3504x2336@72dpi you would end up with a print of ~4'x2.5'

72dpi is just an approximate pixel pitch of most monitors (at least I think that's where it originated, a 20" monitor will have approximately 100 dots per inch of horizontal screen space now). Even that doesn't really count as dpi is really only for printing.

(Sorry, not really relevant to the thread but this was the straw that broke the camels back so to speak, there are way too many people thinking sticking 72dpi in PS is going to do anything at all).

I've always been led to believe, correctly (I THINK):

That DPI is relative to actual print size. And the higher DPI the more detailed the print. So for my laser printer, I send it 300dpi (in photoshop) images and they look CRISP. However, when sending a 72dpi (standard monitor quality) it will come out looking like an inkjet.

And to conclude, upping the DPI of an image will reduce it's ACTUAL size in print. Hence, if he'd like to print that at 300dpi Photoshop will automatically tell him the physical size of the print. On the other hand, he can enter the size he wants and it'll out him the dpi it'll be printed at.

This is only relevant to bitmapped images etc. If you're developing at logo etc you should be using a vectored image so that instead of bitmap, it's using a mathmatical algorithm and the colours to scale enlarge and maintain size at the new dpi.

I'm a beginner and please correct me if I'm wrong :)
 
You're correct.:)

DPI is relevant to print size, however when getting something printed by professional printers it doesn't make any difference what you set it to (unless you go to a printer designed for "professionals" and designers) because it will be overridden anyway (they will work out the DPI/interpolate to the DPI of their printer, which will usually be either 300DPI or 240DPI, and the size of the print you want).

The reason your printer does what you say is because you are telling it the DPI to print at, if you leave the DPI blank in photoshop* it will print at it's default DPI (which will probably be either 240 or 300DPI). Set the DPI above what the printer can print and it will probably ignore it and print at the highest DPI it can print. Set the DPI below the max it can print and it will probably stick to what you told it to and as in your example will probably provide a worse print.

So essentially there is no need to set it to anything because at best it will be irrelevant (professional printers and higher DPI) and at worse you will make the print worse (lower DPI). If you are interpolating the print for larger prints then it may be potentially useful to work out the right resolution to interpolate and enlarge the image but other than that (or you are a professional working in advertising etc.) then leave it. :)

*If are using professional printing software then you may have to set the DPI manually, in which case you probably know what you're doing, and even then you'll probably print at max DPI most of the time, I'll leave it to the likes of MK though as this is above what I know.
 
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Ok.. I see! The reason I'm aware of dpi/actual size is when creating a background for a dynamic table I had to scale the ACTUAL size of the image (8cm by 3) and if I let it decide, as it was printing a 'webpage' it'd print at 72dpi. Which looks unprofessional. So the option was to div the layer and restrict the image size, that way I could resize the 600dpi 2000pixel image down to the 400px web size yet keep the quality.

All I know is, when in photoshop, if I set the dpi/ppi down to 72, it looks bad on print but fine for web, when I set it to 300 at same physical size obviously there are more pixels, therefore bigger image size yet maintaining actual print size.

Point is, 72dpi/ppi for web development as that's the standard quality when viewed on a display. 300/600dpi when printing flyers/posters/high quality art.

Once again, my info only gathered from running club nights in London and being the general printer and designer for them. Using a Dell £800 colour laser printer capable of 600dpi. And it sure does make a difference on 120gsm+ paper. :)
 
Thing is, setting a 600x800 image at 300dpi or 72dpi will generally show exactly the same on screen. When printing out it may look very different however. At least that's how I see it. :)
 
Yes dpi stands for dots per inch and is only relevant when walking about physical print. Else on screen the image will simply contain more pixels - be bigger.
 
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