I've got a new client who is concerned about the size my images can be enlarged to. They want to go 2 metres x 3 metres for exhibition banners.
Viewing distance may be fairly close.
I'm trying to see some of there previous work to see if it's "join the dots". They're used to scanning medium format. It's architectural/industrial work. so hopefully tripod mounted 100ISO or 50ISO stuff.
Thanks

Peter,

The native rez is 4992 x 3328, so at 71 pixels/cm w/o interpolation you get 70.4 x 47 cm. I've upsampled less than optimal files (shot wide open at low shutter speed and 400 ISO) to 150% with no issues. To get to 300 x 200 cm, you'll need about a 426% upsample. At close distance viewing, this could be an issue unless you're very careful shooting and RAW processing!

A few days ago, I uprezzed a older RAW - a 8 MP 1 D-2 - to 80 x 120/400 dpi; "printed" on a Lamda.

It went fine, with dig. artefacts beeing visible only at very close inspection, aka <10 cm

The RAW-edits were very carefully done; RAW Developer, scaling to the highest possible, to avoid furter edits in PS.

Sharpening was applied - apart from a very low sharpening in the converter - in the Lamda's hardware RIP.

If there's something like a Lamda and a Hardware-RIP, IMO it's better to let the RIP do the work. I had to compose in PS, therefore I went to the big size straight out of the RC - with little sharpening - applied the layermask in PS, but didn't made the sharpening, as this was done in the RIP later. It's alwith possible to sharpen in a RIP, but hard to smooth it. Nothing looks uglier than oversharpend prints.

If you bubble yourself, I'd do a 3-step sharpening.

With a 1 Ds-2, 80/120 cm/400 dpi should work without any artefacts, if the RAW edits are well done, and the lens is topnotch.

quote:

Originally posted by Peter W:
I've got a new client who is concerned about the size my images can be enlarged to. They want to go 2 metres x 3 metres for exhibition banners.
Viewing distance may be fairly close.
I'm trying to see some of there previous work to see if it's "join the dots". They're used to scanning medium format. It's architectural/industrial work. so hopefully tripod mounted 100ISO or 50ISO stuff.
Thanks

Good afternoon Peter W.,

I worked on a banner image for an advertisement for a large coffee company, and a large electronics company promotion. The image they provided was only a 72 dpi 1.5" square file, with clipping path. The final print was about 24" square, though all of these would be hung at just above eye level.

The tricky part was to make sure the image did not look too soft, which involved getting really clean edges. In my situation above, the printing method was only good enough to require 200 dpi at 24" square, so not a huge file size. That was quite a step up. The work was done in stages of enlargement, with a few test prints prior to final delivery. I think going beyond the size needed, then downscaling to the final size helped a bit. Careful use of various sharpening methods probably helped too.

You might want to work on a few different variations of the same file. That way you can try a couple methods, and come up with something that works. I think just upscaling in one step is unlikely to give you the best results.

Something odd you might want to try, if you have the time, is to let your layout software (or the desigers layout software) handle the upscaling. To do that, you need to have the image file as an EPS (or DCS if the printing place handles that). I will warn you ahead of time this does not always work best, but if your subject matter in the images is mostly geometric in nature, it can sometimes solve large printing problems, and keeps file sizes reasonable.

Try to get some information about what printing methods are being used. If they can tell you the specifications needed for their large outputs, it can make your life a bit easier. Best of luck with this.

quote:

Originally posted by Peter W:
[qb] They're used to scanning medium format. It's architectural/industrial work. Thanks [/qb]

The files from the Canon will exceed the scans they are used to using if you use a good lens. Architectural is usually done on wide lenses so you may have problems due to Canon making Uber Krappy wide lenses. This from a former Nikon user who switched to Canon!

P.S. Still glad I made the switch!

NOT to pile on to Peter's post.. but i am really new to this "upsizing" of digital images/files .. i do own a 1DS MK2 and LOVE IT !!,.. What is the best way to enlarge prints to Super size ?? What are your methods and Programs.. ??
Thanks to ALL,

cw

PhotoKit Sharpener helps a lot.

I use Bicubic Smoother in Photoshop CS or CS2.

and yes Photokit Sharpener does help!

Piktour,

These are the results from my 1ds mk2 or scanned 6x7cm transparencies:

1ds Tiff file about 47Mb
Imacon 343 file size 150Mb

I always shoot jobs which require quality, ie 99% of them, on medium format transparency.

Adrian Wilson
www.adrianwilsonphotography.com

Adrian,

Do you have any side by side comps of both formats sized to 150 megs?

Peter,

I had to do something similar, a shot to be printed with good res at close-up inspection, and then no way to go film as it was shot at 4:00PM and printed at 7:00 PM. I've put up here for download a sample that compares a raw enlarged section to a tiled one. The link will only work for a week, if someone can put it up somewhere else.

You can make tiled shots easily with this software if their information is true. I definitely find tiling a great solution with true resolution, and all the talk about getting sufficient definition from a careful in computer processing sounds doubtful to me (I tried!): you won't get beyond your lens and capture capacity no matter what software you use.

I've just had some strips made from a file from a 1Ds2 at 80DPI on an Epson 7800. Not bad at all. As if blown upto 2m x 3m. Next I'll see if I can interpolate up to same size at 150dpi.
I had an image blowen up to 1m at 150DPI. Absolutely no problem

quote:

you won't get beyond your lens and capture capacity no matter what software you use.

Yep, that's very true. How did you produce that tiled shot (hardware/software). I'd expect the added detail but why do the highlights look so much better? Nice work for sure, I'd love to hear how you did it.

Peter, it sounds like you're answering your own question. Up-sizing the image then printing a crop on a small format printer is good, cheap way to test different techniques.

quote:

but why do the highlights look so much better?

Kevin, The lighting has obviously changed from shot to shot.

I used a Canon 20d mounted on a 4x5" view camera with a Mamiya RZ 50mm lens on the front, tiling six shots total. The backup shot was done with a Sigma 12-24 mm on the same 20d to give similar coverage.

Highlight quality and finer graduations has much to do with resolution, just like when comparing 35mm and 120 film shots. Lighting may have varied as it was ambient light plus two or three 900 w/s monolights, but the day was cloudy and daylight varied continously.

Software was PS CS: each layer in "Difference" mode to make positionning precise and also help draw an irregular mask that makes a perfect match with underlying image. The technique has worked so well I use it for panorama stitching also. Hard work but good results.