DESPARATE FOR ADVICE ON LARGE IMAGE PREPARATION FOR PRINT

[Mark Couch]

No need to apologise Helen, I will be experimenting with all suggestions and it's great to know that people are willing put ideas forward.

Thanks for your support.

I will try Bludvlz's solution, however, I will probably have to make some compromises as my images are often viewed up close but it definately sounds useful.

[Gernot Hoffmann]

Mark,

33" x 138" by 200 dpi means 6600 x 27600 pixels.

If your source images have these pixels then you can leave it
that. If they have less, then it´s quite useless to blow up the
images by PhS bicubic.

Raster image processors can handle large images and if the
number of pixels is too small (e.g. 100 dpi on the paper) then
the RIP will do its best by interpolation.

Hopefully the printshop doesn´t try to print by PhS.
Such a task needs RIPs like PosterShop or Best ColorProof.

The calculation time depends not only on the number of pixels
but also on the printed area and the resolution. More than 720 dpi
inkjet resolution is nonsensical.

Best regards --Gernot

[Gernot Hoffmann]

Gustavo,

the reduction of the source image pixel size doesn´t reduce the
computational costs unless the resolution of the printer is reduced.
Printed square meters count.

Why should any large format printer tile an image when it could
be printed in one piece ?

Tiling is necessary if the printer is too small.
Tiling is by no means simple. We have tiling with overlapping pieces
and tiling with contacting pieces. Large format RIPs offer both alternatives.

One reason for tiling could be the reduction of the risk:
If the printing of a tile fails then just one part has to be printed once again.

An image 800mm x 3500 mm can be printed in one piece (maybe not by PhS).

Best regards --Gernot

[Mark Couch]

Gustavo,

The how close senario is the clients nose 6 inches from the print picking out every minor error in presentation.

I don't quite follow your tiling suggestion could you elaborate?

The way in which I am working is to produce an eps file from Microstation or AutoCad which I then distill to pdf to take into photoshop, where I then colour up and add atmospherics, but as I said originally, the clients like to be able to check elements with scale rulers which means I am restricted to working at the same sheet/image size as the original CAD file. So I am often working on images 841mm x 594mm (A1) or larger and to retain definition of the printed image I can not work any lower than 150 dpi.

If you have any other suggestions I'm all ears, if I can reduce the time required for getting a print produced it will give me longer editing time and therefore a better quality image.

Regards,

Mark

[Gernot Hoffmann]

Mark,

the only problem is your printshop.
A1 with 200dpi (source image on the paper) can be easily printed
in a reasonable time. The rendering time will be about 10 minutes
(guess) and the printing time is 40 minutes for 700x1000mm on
a large format inkjet, using RIP software.

Best regards --Gernot