Image Resizing batch?

fujitsu1522 · 13-09-2007, 16:28

Being new to photoshop progs, i need to resize all my images 300 dpi to send to a printer for ultimate quality I have been told, can i do this in batch, I am doing a lot of weddings this year and next, normally i just take them to a family printer, but i have come across a printer that used to be very expensive years ago, but now they are megga cheap, and they come highly recommended, all my images have to be resized, or is there a program that would make this task quick, Nikon D50 user. software is not a problem, I have access to any pc software you can recommend, or maybe there is a step by step guide for this, sorry to sound stupid, just getting into programs learning slowly. thanks for any advice.

Dave Canon · 13-09-2007, 16:50

Using PhotoShop, you can create an Action by manually changing one picture. After saving the Action, you can use it in batch mode to change a folder full of pics.

orangepeel · 13-09-2007, 17:02

dpi (dots per inch) isn't a measure of size. At least not directly. Your D50 uncropped produces images of 3008x2000 pixels (or dots)

which when printed @ 300dpi means a max size of: -

10" x 6.66" (Just under A4 size)

You can print larger than this apparent maximum but this is done with interpolation - ie software guessing what the intermediate pixel colour should be - allbeit an educated guess

Really you should need to tell us what print size you want then we can tell u how to achieve it.

silkstone · 13-09-2007, 18:20

Just to add to what O-P says, the 'native dpi' of 300 dpi (or whatever) embedded in the file data is (almost) meaningless. What matters is the actual size of the image in pixels, the size in inches at which you want to print and the resolution in dots (or lines) per inch required by the printer.

Many commercial printers ask for 300 dpi, so if your image is, say, 3000 x 2000 pixels it can be printed at up to 10" x 6.6".

Desktop printers usually give best results at somewhere around 180 dpi, so the same image can be printed at about 16.6" x 11.1". In practice you can print larger this with little discernible loss of quality.

fujitsu1522 · 13-09-2007, 18:24

Thanks for very quick input, I have just been given a adobe Photoshop book " Lightroom Essentials" I believe this software might help me resize my images, getting the software will not be a problem, there Is so much to learn using adobe products, and it is all down to time, but the images I normally work with are:
6x4 7x5 8x6 10x7-10x8 - sizes available that i might use could be 16x12~18X12
So I believe resizeing is to allow for cropping?, without loss of quality, I would like to read maybe an explanation on the subject, coming over from Film to digital, maybe someone as wrote an explanation on this, I know when I have done test prints at a local nini lab~ proofs I have lost some of the image, this could be why?, thanks for any more input. and thanks for your time.
Pete.

Dave Canon · 15-09-2007, 21:46

Pete, you can think of re-sizing and cropping much as you would have in a darkroom.

You place a specific size of photographic paper on the enlarger board then adjust the enlarger to fill the paper. Often you may over enlarge to ensure unwanted parts of the picture fall off the paper and is thus cropped.

In Photoshop or other imaging software consider the Resolution as setting the enlargement and you can visibly crop the picture using the cropping tool. If you continue to increase the enlargement in the dark room, you will find that the picture will appear softer and more grainy as you are limited by the information on the film. It is similar for digital, if you try to over enlarge the picture will appear softer and you will eventually see individual pixels rather than grain.

There are lots of video tutorials covering this and many basic photoshop techniques which is an excellent way of learning.

fujitsu1522 · 19-09-2007, 12:20

Many thanks, I have lots of books, and will take in whats been said, cheers guys.

orangepeel · 19-09-2007, 12:35

by a strange coincedence, I just got sent this: -

How Big Can I Print by Thom Hogan

silkstone · 19-09-2007, 21:24

That's rather at odds with the advice given by a big-wig at Epson on another forum, who said that anything over 180 dpi is unnecessary on a desktop printer and gives no additional benefit.

Maybe we could get some clarification on this from other printer manufacturers.

orangepeel · 19-09-2007, 21:42

best bet is to test yourself no? Should be easy to check.

silkstone · 19-09-2007, 21:49

I've never seen any improvement at over 200 dpi on the i9950, although lately I've been printing from QImage and that reinterpolates to 600 dpi (allegedly) irrespective of the actual resolution.

I've not done much printing recently - house full of prints, no more wall space and basement out of action for another few weeks yet. I want digital frames to get a lot cheaper.

Dave Canon · 20-09-2007, 18:15

I generally print between 200 and 230 on my Epson 1270. It is a long time since I checked but I could see a deterioration below 180 ppi. I am not sure that I could defintely tell 200 from 230. I suspect that with a more modern printer, you may be able to see the difference though.

21-09-2007, 00:54	#13 (permalink)
fujitsu1522 Getting Comfy Join Date: Feb 2007 Location: Wales Posts: 150