Printing Large images for wall art onto canvas or similar

[martin192]

Hi everyone this is my first post on the site, and not too sure if this is thread is in the right section but I have been searching the internet all day to try and find out the answer to this question.





I took this picture the other day and I fell in love with it, I understand to some people, say more experienced, may think that it is not all that great but in my few months of taking pictures it is by far one of my best! Anyway the point is my mum loves this kind of photos and the thought of having her own son's art on the wall sounds pretty perfect to her.

So my question is this, how big could I go on, say a canvas, before the reduction in quality is noticeable? It was shot in RAW and the post processing was done using google's picassa 3 on a very high power computer(dunno if that matters) so any information you may have would be greatly appreciated

Thanks

Martin

 

[Flint350]

Difficult to say without knowing the pixel dimensions of the image. However, it is generally accepted (some will surely argue this) that a good printer needs somewhere between a minimum of 180 ppi to a max of 480 ppi at NATIVE resolution of the image. That means, no re-sampling. So, if your image size shows 3000 X 2000 pixels, you can divide those numbers by the intended print res. of 180, 240, 360, etc to see the various NATIVE print sizes available without having to resample. If your printer is an Epson, it is often advisable to use 360 since that is Epson's native setting. Or, on an HP, use 300. But, you don't have to. If 360 gives you too small an image (3000 X 2000 / 360 = 8.5" x 5/3") you can use 180 and double that.

Viewing distance of larger images is usually far enough back that printing at lower resolution like 180 (a minimum IMO) is sufficient. So, go into Photoshop and look at your image size and in the resolution box, uncheck "resample" and input the resolutions 180, 240, 300, 360 and see the print size results. It's done automatically to save the math. Bigger than those and you will need to resample either in Photoshop or Genuine Fractals, etc. Hope this makes sense.
--
'You cannot reason a person out of a position he did not reason himself into in
the first place.' -Jonathan Swift

 

[Howard Moftich]

it depends on good your mum's eyesight is

but seriously, you'll want to keep it above 130-140 ppi for anything to look even remotely decent and at that, be standing back a few feet.

 

[chipster2]

Hi everyone this is my first post on the site, and not too sure if this is thread is in the right section but I have been searching the internet all day to try and find out the answer to this question.





I took this picture the other day and I fell in love with it, I understand to some people, say more experienced, may think that it is not all that great but in my few months of taking pictures it is by far one of my best! Anyway the point is my mum loves this kind of photos and the thought of having her own son's art on the wall sounds pretty perfect to her.

So my question is this, how big could I go on, say a canvas, before the reduction in quality is noticeable? It was shot in RAW and the post processing was done using google's picassa 3 on a very high power computer(dunno if that matters) so any information you may have would be greatly appreciated

Thanks

Martin

Martin,

I see that you used a Sony Alpha A-350 for this picture. If my calculations are correct the image size should be approximately 3076 X 4614 pixels. I think that you should easily be able to print up to 24" X 36" without a noticable drop in quality. You can print even larger and still look good since the larger the print, the further away people tend to view it from. (Except for other photographers that tend to get up really close)

I believe that the most critical size for sharpness and resolution is 8 X 12 since most people view that size from normal reading distance.

Assuming that you have this print made at a Pro lab, they should use a RIP that will upsize and sharpen the photo so you will be pleased with any reasonable sized print.

Chip
--

'I have yet to see any problem, however complicated, which, when looked at in the right way, did not become still more complicated.'

 

[martin192]

thank you for all your replies. the first reply is rather technical but I think I got the jist of it! and as for my mum's eyesight well thats poor but my 13yr old sister's is fine and im sure she'd take great delight in telling mum that golden boy isnt so golden haha! and your pretty much bang on with the pixel size and the 24" by 36" would be more than enough I was hoping for around 24" on the longest side.

thanks again!

Martin

 

[apaflo]

thank you for all your replies. the first reply is rather technical but I think I got the jist of it! and as for my mum's eyesight well thats poor but my 13yr old sister's is fine and im sure she'd take great delight in telling mum that golden boy isnt so golden haha! and your pretty much bang on with the pixel size and the 24" by 36" would be more than enough I was hoping for around 24" on the longest side.

thanks again!

Martin

There are a couple other considerations which probably work out in your favor.

Printing on a textured surface, such as canvas, reduces the amount of detail that can be seen. It works best for images that do not rely on sharpness for their appeal. Your image is, I think, a classic example of exactly that kind of an image. Imagine, for example, an oil painting of that scene on a 6' x 4' canvas! It would not require any significant fine detail, even if viewed from only 10 feet away.

It is virtually impossible to look at a 800x533 pixel image on a computer screen and determine how sharp it looks at the original 4000x2600 size, never mind when rescaled to be printed at a 24"x16" or larger size. Hence we cannot tell if your image is sharp enough, and have to assume that it is. (Probably a very good assumption if you like the shot when looking at it close up.)

As far as technically how to get the best print... you need to find out the native pixel per inch value of the printer it will be done on. For example, Canon and HP printers use 300 PPI, Epson uses 360 PPI, and various commercial printers have other values, such as 204 PPI for a Fuji Lightjet.

You want to re-sample your image, at the native PPI of the printer, to be the right number of pixels for the size you want. Hence, a 24"x16" to be printed on a Lightjet at 204 PPI should be scaled to 4896x3264, but if it will be printed on an Epson 7900 at 360 PPI it should be scaled to 8640x5760.

Note that the amount of sharpening to apply to an image at 4896 pixels across and to the same image at 8640 pixels across is significantly different to get the same visual effect!

At that resolution it should be appropriately sharpened. To judge the sharpening you'll need to crop out a section of the print at approximately the PPI of your computer screen. If your screen is, for exampe 96 PPI and you can look at an image that is 15 inches wide on the screen, you'll want to zoom in to where you are viewing a 1440 pixel wide section of the image while adjusting how much sharpening to apply.

You will also find that using Unsharp Mask is not as effective for images that have been scaled up as it is for those that have been scaled down, while a high pass "sharpen" tool is more effective. Hence what you do to the image to make it look good for viewing on the web is very different that what makes it look good for printing at 24"x16".

Send the sharpened higher resolution version to the printer.

That sounds complicated, but if you read through it a couple times it is not difficult to follow the logic.

Another possibility is to make the original RAW file available for download, and I and perhaps others too, would be happy to "massage" it and provide a JPEG file that you can download and print. You would need to specify the physical size in inches (which must match the aspect ratio of your image, or you need to provide cropping instructions) and which type of printer it will be printed on.

 

[Vernon D Rainwater]

Hi everyone this is my first post on the site, and not too sure if this is thread is in the right section but I have been searching the internet all day to try and find out the answer to this question.





I took this picture the other day and I fell in love with it, I understand to some people, say more experienced, may think that it is not all that great but in my few months of taking pictures it is by far one of my best! Anyway the point is my mum loves this kind of photos and the thought of having her own son's art on the wall sounds pretty perfect to her.

So my question is this, how big could I go on, say a canvas, before the reduction in quality is noticeable? It was shot in RAW and the post processing was done using google's picassa 3 on a very high power computer(dunno if that matters) so any information you may have would be greatly appreciated

Thanks

Martin

Martin, you have received good suggestions regarding size and resolution. However, may I suggest you consider lightening the Picture slightly. The image has lost almost all of the details in the Shadow (Darker) areas. I Downloaded the image (and even though it is small for posting size) -- I checked the image in Photoshop using Levels and there are basically NO details in the upper (Highlight area) in the 200 through 255 range.

I suggest you consider checking this and see what you think by changing the upper Levels area from 255 to 200 -- and see what you think on your Monitor.

This change will allow many of the Shadow areas to show more details and (in my opinion) should be helpful for the image. The overall area of clouds will somewhat brighten and allow the overall scene (the image) to not appear to be somewhat "gloomy dark gray" or overcast.
--
Vernon...

 

[j_photo]

I'm brand new at this myself and I am also trying to print an image at large size. Maybe my experience, newbie to newbie will be helpful.

My original image is 4928 pixels wide. I have been ordering partial test prints online at adoramapix.com, 12 x 18 prints at about $7 each. So far, I've gotten results that I like at 120 dpi.That works out to an overall print width of about 42 inches (4928 pixels / 120 dpi). They will print down to 100 dpi. My test print at that resolution isn't ugly, but it's softer than I would like.

Wider prints get pretty pricey. But the plan is to print a tryptich (3 panels), so each print will be quite reasonable in size. The cost of mounting will probably be more than the cost of the printing.

Hope that's helpful to you. Joe

 

[apaflo]

I'm brand new at this myself and I am also trying to print an image at large size. Maybe my experience, newbie to newbie will be helpful.

My original image is 4928 pixels wide. I have been ordering partial test prints online at adoramapix.com, 12 x 18 prints at about $7 each. So far, I've gotten results that I like at 120 dpi.That works out to an overall print width of about 42 inches (4928 pixels / 120 dpi). They will print down to 100 dpi. My test print at that resolution isn't ugly, but it's softer than I would like.

Wider prints get pretty pricey. But the plan is to print a tryptich (3 panels), so each print will be quite reasonable in size. The cost of mounting will probably be more than the cost of the printing.

Hope that's helpful to you. Joe

Something you want to try before committing to ordering the large prints for the final product, is adjusting your DPI concepts a little.

Find out what their printer actually prints at. For example, LightJet printers made by Cymbolic Sciences print at 12 or 16 lines per mm, which works out to 304.8 pixels per inch or 406.4 pixels per inch. Older LightJet printers used 200 PPI, Durst printers are 200 or 400, and Chromira printers are 300 PPI.

The reason you want to know is so that you can scale your images to the desired resolution, and actually preview what they look like (and, for example, adjust the sharpening to your tastes) rather than let the printer do it with generic settings (and generic results).

With your example of an image that is 4928 pixels wide, which you think they would print at 120 DPI to get a 41.07 inch wide print, in fact will be scaled to some other resolution first, and then printed. For example, if they use a Durst printer it would be scaled to 400 DPI, or 16,427 pixels wide, before printing. Your 12x18 print to test the work, at 120 DPI should be a 1440x2160 pixel crop from the original in order to show what the results will look like if the original 4928 pixel wide image is sent for printing. But it too is going to be scaled to whatever the native DPI requirement for the printer actually is.

Hence for the most critical results, you should scale the original 4928 wide image to 16,427 pixels wide, and the 12x18 test print should be made from a 4800x7200 resolution crop from that image, if we assume a 400 DPI printer.

The significant point is that after the image is scaled to that size you want to apply High Pass Sharpen in particular, and perhaps Unsharp Mask too, to suit your tastes. To judge the effect, look at a zoomed in 100% crop while you adjust it. Do that by determining the DPI of you monitor screen (for example, 96 DPI is common) and configure your image editor to have a resolution index in pixels which you can measure with a ruler. Set the zoom so that 960 pixels (or the actual appropriate number) takes up 10 inches width on the screen. Then apply sharpen and judge the effect. Then crop out the 4800x7200 section for a test print and send it off.

That procedure allows you to preview and adjust as closely as possible before the image is actually printed.

 

[j_photo]

Something you want to try before committing to ordering the large prints for the final product, is adjusting your DPI concepts a little...>

This is helpful. The test prints were fun, and it helped a lot just to see parts of the image at larger, printed size. I'll try your suggestions for previewing on screen--it will be interesting to compare with the prints.

I think, next, I am going to go visit a local print shop, talk face to face, and plan on doing the final printing there. As you and others are saying, there is more to consider and I'm going to need a bit of help to get the best possible results.

Thanks for the info. Joe