Pages: [1]   Go Down

Author Topic: Composite images on canvas  (Read 2980 times)

TonyW

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 643
Composite images on canvas
« on: March 04, 2014, 06:22:44 am »

I have been asked to produce a composite comprising of 36 images (from a P&S camera) to 20"x16" maximum size printed to canvas.

Attached is a quick test of layout after bringing the images into LR and resizing and printing to file

Personally I am not that keen on canvas prints, although I am sure with the correct subject matter they can look fine.  In this case I will be sending the file to a lab for printing and mounting but prior to this I do have some concerns about the potential final look of the image.  I feel that it would be much better to print to normal paper rather than canvas

Print size 20"x16"
No. Images 36 - varying sizes
Smallest image 3"x2"
Current 150 ppi file size 20.6MB

At LR default print to JPEG the file resolution is 150 ppi, but as the print is likely to be viewed much closer than what may be considered 'normal' viewing distance for a 20x16 I feel there is just not enough file resolution and this should be increased.  But then there is the issue of how far to go due to the nature of canvas and the ability to resolve detail.  I know that these are only holiday snapshots but faces should still be recognisable  ;D

So I would appreciate any advice/suggestions

Logged

howardm

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 1984
Re: Composite images on canvas
« Reply #1 on: March 04, 2014, 07:43:37 am »

I dont think the 150PPI is relevant here.  A .jpg doesn't have a native PPI/DPI, it's just a x/y grid of pixels.  When you actually put
the pixels to canvas, you determine the PPI/DPI.  Also, consider, (and just using some random values here), a snapshot from the P&S
in question might be 3000x2000 pixels and you're printing full image, so add up the pixels in each direction and divide by the canvas
dimension in that direction and you have the true PPI/DPI.  I.e, 2000 x 10 (pictures in that direction) / 16 (size of canvas in that direction) yields something like 1250 DPI.  And canvas is going to be a loser for 'detail'.

So use something like Preview (on a Mac) or ?? on a PC and see what the file image size in x/y is and divide by canvas x/y.

TonyW

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 643
Re: Composite images on canvas
« Reply #2 on: March 04, 2014, 11:43:37 am »

Howard, thanks for your reply.  I am aware of the calculations you provided and I think that perhaps I did not illustrate my concerns about this particular image relating to canvas prints (of which I have very little experience)

My main concern is that the PPI is relevant relating to viewing distance and in this case a ‘normal/suggested’ (based on 1.5x print diagonal) viewing distance for a 20x16 would be around 38” (for none photographers!) and could in theory only require 89ppi and still look acceptable at a ‘correct viewing’ distance.

But in this particular case there are a number of separate images some as small as 3”x2” which are going to be viewed much closer maybe 10-12” therefore ideally should need a higher ppi.

So accepting that canvas by the nature of its surface reduces the ability to distinguish fine detail there must be a point where it is no longer beneficial to send more pixels as there will be no visible gains.

As usual a net search seems to provide much conflicting information some drawing a line in the sand at 100ppi, some higher up to 250ppi.  I guess it will also depend on the quality/coarseness of the canvas and the printer’s native ppi?
Logged

philbaum

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 72
Re: Composite images on canvas
« Reply #3 on: March 04, 2014, 01:06:57 pm »

I think you've got your standards set too low on ppi.

For digitial screen viewing, the old standard was 70 ppi, which is now 140ppi.

For printing, the old standard was 240ppi, and now its 360ppi.

I print all my canvas at 360 ppi.  If you're worried about file size, then you can use some jpeg compression.

But i've sent prints to commercial canvas printers at 360 ppi and got back excellent quality.  One at 24"x36" sold for $350 recently.
Logged

TonyW

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 643
Re: Composite images on canvas
« Reply #4 on: March 05, 2014, 10:46:22 am »

philbaum thanks, I agree about the low ppi and in fact lost sight of the fact that I would not be printing this particular image :-[  So made a couple of enquiries to commercial printers relating to their file requirements.  Probably makes the most sense to adjust to use the printers native ppi wherever possible?

One came back with the answer "the pictures will be saved with 150 dpi and this is also the resolution we use for printing.", and also had a limit of 20MB file and no comment about icc profile!

Happier with the second reply printing to a Fuji Frontera and file specs asked for 300ppi or they would uprez.  although still no profile which came as a surprise!
Logged

Wayne Fox

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 4237
    • waynefox.com
Re: Composite images on canvas
« Reply #5 on: March 05, 2014, 05:29:33 pm »


Happier with the second reply printing to a Fuji Frontera and file specs asked for 300ppi or they would uprez.  although still no profile which came as a surprise!
A Fuji Frontier?  I thought you said it was on canvas.  The frontier produces chemical prints ... no canvas.  Maybe you’re trying to convince them to use paper instead of canvas.

Quote
Print size 20"x16"
No. Images 36 - varying sizes
Smallest image 3"x2"
Current 150 ppi file size 20.6MB
I think the file size issue you are seeing is a non issue.  Once you get the image ready to print, you will produce a jpeg file.  Even a high quality setting jpeg file at that size would be well under 20mb.  If the place is limiting the actual tiff size to 20mb probably need to look elsewhere.

I would also shy away fronm a lab throwing out the 150dpi number.   No reason for that.  Yes canvas can’t hold up the detail much better than that, and faces should be fine, but most output houses should be able to work with a 280 or 360 dpi number. 

So I would make the file 20x16 by 360 if printing to canvas, 300 if printing to fuji frontier.  Arrange everything, when it’s perfect, flatten it, save it as a jpeg file at highest quality.
Logged

TonyW

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 643
Re: Composite images on canvas
« Reply #6 on: March 05, 2014, 07:17:34 pm »

A Fuji Frontier?  I thought you said it was on canvas.  The frontier produces chemical prints ... no canvas.  Maybe you’re trying to convince them to use paper instead of canvas.
Wayne many thanks for this I had not even realised that the Fuji Frontier is a chemical printer (the Frontera was a car and Fuji do not make them yet  ;D) - been out of the loop really just making my own prints and never on canvas.

Quote
I think the file size issue you are seeing is a non issue.  Once you get the image ready to print, you will produce a jpeg file.  Even a high quality setting jpeg file at that size would be well under 20mb.  If the place is limiting the actual tiff size to 20mb probably need to look elsewhere.

I would also shy away fronm a lab throwing out the 150dpi number.   No reason for that.  Yes canvas can’t hold up the detail much better than that, and faces should be fine, but most output houses should be able to work with a 280 or 360 dpi number.  

So I would make the file 20x16 by 360 if printing to canvas, 300 if printing to fuji frontier.  Arrange everything, when it’s perfect, flatten it, save it as a jpeg file at highest quality.
Yes, the file size for me at least is a non issue and in fact a JPEG at 300 ppi is around 18.4MB and at 360 about 22.7MB.  I have totally ruled out the lab that quoted 20MB and 150 dpi numbers.

I think that I need to do a little more research on where I am going to send the file and find out exactly what printer is being used for canvas as I guess that the 300 ppi figure would be based on either Canon or HP and if 360 ppi this would be Epson.  The fact that no profile required also concerns me with the second lab, quote "With regards to the profile we will take care of this for you we only require you to do it for standard photographic prints".  So I think a little more research in order  :)
« Last Edit: March 05, 2014, 07:22:03 pm by TonyW »
Logged

enduser

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 610
Re: Composite images on canvas
« Reply #7 on: March 07, 2014, 07:01:57 pm »

A very price effective way of nesting or making a collage is to use "Qimage".  The program is cheap and has a free demo, and it will allow several ways of arranging multiple images in one print.  It also allows a different color profile for each one if needed, (or all the same).

If you're a Windows user, OK.  If not, many Mac users run it under emulation.
Logged

shadowblade

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 2839
Re: Composite images on canvas
« Reply #8 on: March 07, 2014, 11:04:10 pm »

If they want one of the images printed at 3x2" on canvas, for up-close viewing, they're going to be disappointed. The resolution just isn't there.
Logged

TonyW

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 643
Re: Composite images on canvas
« Reply #9 on: March 10, 2014, 11:37:41 am »

enduser, I have had a look at Qimage and it appears to be very comprehensive and many seem to sing its praises.

shadowblade I agree and have made the point to them on several occassions
Logged
Pages: [1]   Go Up