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Viperman500
04-19-2007, 12:00 PM
Hi, I was thinking about printing a picture (24x36) with an 8 megapixels E500. I asked someone how big I could do it, he told me 11x14. I find that's not big enough. I guess he told me that so I could get the best quality possible. How big can I print without losing to much quality?

Bojan Volcansek
04-19-2007, 12:34 PM
11x14 is probably with 300dpi from 8MP camera.

But if you use interpolation - or use less then 300dpi, or use combination of the 2 you can print MUCH larger.

I know that some forum members printed REALLY large. I hope they will help you with some tips!

Yours Bojan

refiningman
04-19-2007, 02:09 PM
One way (I think the best) is to take one of your RAW images, then resize it in Photoshop (Image>Image Size) and set the resolution to 240 dpi, which is about as low as you really should go, without resampling set on. Then see what the resultant image size will be in inches. That is your answer.

Peter

rally
04-20-2007, 01:37 AM
I have no experience doing it, but I have read of various people's techniques for resampling to create large format prints using 8mp images - so it is being done.

"Focus Magic" claims to be able to resize an image up to 4 times larger in size by using a technique which restores detail.
http://www.focusmagic.com/exampleincreaseresolution.htm

To Quote - 'The "Increase Resolution" is commonly used to print large prints from small images. It first doubles (or quadruples) the width and height of the image to produce the intermediate image, and then uses advanced interpolation techniques to remove the "pixelized" effect. For a low resolution image it produces a much better result than simply increasing the image size through Photoshop, Paint Shop Pro, etc'

They also claim to use a deconvolution process to restore detail in blurred images - if their web page is any true indication it is positively amazing - they say their software is used in forensics.
It was Jebir (thank you) who alerted me to this amazing software in a recent thread.

One technique posted on another site for Bird photos for printing 20"x30" posters was as follows
1. Convert RAW to 6144 x 4096 16-bit TIFFs in ACR, no sharpening.
2. Perform adjustments in PS - levels, contrast, curves, etc. but no sharpening yet.
3. Resize up to 10800 x 7200 using bicubic smoother, then perform local and global sharpening (a bit on the aggressive side).
4. Resize down to the final 9000 x 6000 using bicubic sharper, apply some more local sharpening where needed.
5. Save as 8-bit TIFF for printing.

I have been busy storing all this background info for when I get my large format printer (soon) - love to hear about your results.

Good Luck

tspore
04-20-2007, 01:47 AM
I took a 5x7 scanned it in, and blew it up to 20x30 for a friend.
I just upsampled in 10% steps using bicubic smoother till I go 20x30" at 240 DPI.
However, if you plan on having it printed some where ask them what the minimum size is for a 20x30. I have done a few from a P&S at costco. I just did the 10% steps (I created a PS action to do this) And they looked good.
Really it should be fine.
Just make sure that you go 10% not in 1 large step.
In PS:
go to actions: and record a new one.
Then go under image/image size
Under document put in 110 percent
Select bicubic smoother (But I really don't see the difference between smoother, or sharper in my experiments.)
then hit ok
Now stop recording that.
Now if you need it to upsize 3 times or 30 times you can just have the action run.
I have tried 4 other programs, and really I haven't seen anything better.

laingjd
04-20-2007, 06:20 AM
Ditto on Tony's method.

I've gotten 24 x 36 out of the E-500, E-330 and E-300 that way.

The second supplier I tried just asked me for the finished file on a disk and he did all the adjusting and it was beautiful.

dodger
04-20-2007, 07:09 AM
Not exactly conventional, but I've just printed up to A2 size using this method in photoshop;

Edit -> Image Size

Put in the required width and height figures (I used the relative option, so only set one). In this case I set the larger of the two figures to 42cm (width of A3 paper). If the smallest of the two is more than 29.7cm (height of A3 paper), then I adjust the larger down from 42.

Set DPI to 300.

Select Bicubic Sharper

Hit ok.

I just got two A3 and one A2 print back from the printers having used that method. I have an A4 copy of each printed at the original resolution (some cropping obviously to get the right aspect ration). There is no reduction in quality that I can see from using the above method.

refiningman
04-20-2007, 08:21 AM
Dodger:

Yes, many people now recommend just using Bicubic Sharper for upsizing even tho' it was supposed to be used for downsizing (and Bicubic Smoother for upsizing). Radiant Vista (Mike Johnson) is one. In these cases, using a stair-step like Fred Miranda's is no longer necessary.

Be sure to run an "output" sharpening routine however to clean up the edges

All of these methods however create pixels - if you want to see the "native" size at a given dpi you need to use the method I stated in an earlier post on this thread.

Peter

Hokuto
04-20-2007, 08:33 AM
Perhaps the easiest way to uprez--if you have sufficient computer memory--is to use Qimage and let it do the work. Print to file (huge) and take the result to your printer.

JonathanS
04-20-2007, 09:15 AM
Hi, I was thinking about printing a picture (24x36) with an 8 megapixels E500. I asked someone how big I could do it, he told me 11x14. I find that's not big enough. I guess he told me that so I could get the best quality possible. How big can I print without losing to much quality?
Hi,
I shoot an E330, and recently had a couple of shots printed up by Mpix that were 24"x30". One is a gallery wrap, and the other just a board mounted print. Both came out beyond my expectations (perfect!).
The pictures were both sized around 2400x3000 pixels.

Naturally a critical aspect of blowing up a print is the degree of sharpness of the original, which is based upon ones use of the equipment and quality of glass. If the original is not absolutely perfect, forget about going to 24x30.
I know we are not supposed to be able to get prints this size out of an
8 mp camera, but it is possible
Jonathan

dodger
04-20-2007, 09:48 AM
Yep, ran sharpening after upsizing, certainly didn't harm the quality any.

I actually ran across the technique in Scot Kelby's Photoshop CS2 book. If I'm honest I got the large sized prints done more as an experiment to see if the technique was as good as Kelby claimed it was. That and I really wanted to hide the breeze bloc some more.

Needless to say I was surprised with the results of the experiment for such a simple technique.

However you are right, native size at given DPI is only available from the method you explained.

Viperman500
04-20-2007, 10:56 AM
Hi,
I shoot an E330, and recently had a couple of shots printed up by Mpix that were 24"x30". One is a gallery wrap, and the other just a board mounted print. Both came out beyond my expectations (perfect!).
The pictures were both sized around 2400x3000 pixels.

Naturally a critical aspect of blowing up a print is the degree of sharpness of the original, which is based upon ones use of the equipment and quality of glass. If the original is not absolutely perfect, forget about going to 24x30.
I know we are not supposed to be able to get prints this size out of an
8 mp camera, but it is possible
Jonathan


Thanks for letting me know that!

jacraine
04-20-2007, 06:16 PM
I have read of people using EL-CO Color Labs for large printing with great results. The web site gives directions NOT to uprez or do anything to the original file and let the RIP technology of the printer do the work.

I have not tried this myself and comes form info gathered from the wonderfully accurate and trusting world wide web. I still might try it because the prices are good. $9.95 for a 20"x30" print with a minimum purchase of 2 (not necessarily the same image).

Good luck,

James

jebir
04-21-2007, 05:06 AM
Hi Rally,


"Focus Magic" claims to be able to resize an image up to times larger in size by using a technique which restores detail.
http://www.focusmagic.com/exampleincreaseresolution.htm

I actually didn't know about that option so I just tried it out.

One drawback that I immediately discovered is that it does not any other format than JPEG and it will only save the upsized file in JPEG (with unspecified compression).

So, to test, I converted a processed TIFF-file to a JPEG with the lowest compression possible.

I then upsized 400% with: Focus Magic (hard edges), QImage (no sharpening), PaintShopPro 8 ("smart size"), and PaintShopPro 8 ("pixel resize" for reference) and printed 100% crops at 600 ppi alongside each other through QImage and scrutinized the output at arms length in sunlight.

My subjective ranking after the test is:

1. QImage
+ accurate colour
+ no pixelation
+ high amount of detail although some noise seems smoothed out (this surprised me)
+ nicest general impression when looking at it

2. FocusMagic
+ no pixelation
+ high amount of detail (including noise)
+ OK general impression
- a clear reddish colour cast on skin

3. PSP8 - "smart size"
+ accurate colour
+ high amount of detail (including noise)
- remnance of pixelation is clearly visible

4. PSP8 - "pixel resize"
+ high amount of detail (including noise)
- very disturbing pixelation

OK, I just wanted to report on this here since I did the tests anyway.

Cheers, Jens.

JonathanS
04-21-2007, 09:08 PM
$9.95 for a 20x30 is an excellent price. I'll have to give them a try.
Thanks
Jonathan

tuthdoc99
04-30-2007, 06:36 PM
I regularly print 13x19 at home from my E500 using Qimage and I get excellent results. I haven't sent anything out for larger but am sure that if the original is sharp and clear then a 20x30 should be easily done with the E500 files. I do shoot RAW and not jpg and print from 16bit tif. I only go to jpg or 8bit if required by the printer.

shrinkpictures
04-30-2007, 11:00 PM
I work with some pretty large files for printing - and have printed stitched panoramas up to 32".

I shoot raw, and when I process the RAW I upsize them within RSP. I usually output the tif's at around 160%. I then to all of my stitching and cropping to produce the final image, and at this point I prepare the file for print.

The Lab I print from requires 250dpi so I usually downsize and sharpen the image as the last step of processing.

I have Printed pano's that end up us a 10" high print ( @250DPI ) from an original 1600 pixels and they stand the scrutiny of looking at them from 2 feet away - you simply cannot tell that it has been upsized.

For up to 200% I would not hesitate to simply process it from RSP.

sokol
05-06-2007, 01:06 PM
you may print as big as you like - even 3x4 metres, but this would only look good from a distance of about the diagonal of the picture (which means: a 3x4 metres picture from your 8 MP cam should be viewed from about 4-5 metres distance, and it will look just fine)

but if you want to view it from closer distance than the diagonal and it still should look good, then use the above mentioned (or other) rescaling techniques, of which the simplest one is: multiply the pixels with the square root from 2 (approx. 1,41) and sharpen the image, then again x1,41 and sharpen, and again and again (it's called bicubical resizing) - sharpening (not overdoing it ...) being the different part of this operation, obviously