Help with a simple PS question ....as usual please

gus

Well simple for anyone but me. Ive just saved a few hundred shots from a big event yesterday & i saved them all at 72 dpi (orignials are quite safe)

Now it looks like im going to start back at the begining & save them at a diff dpi :bash :bash :bash (i cant just change that 72 to 500 can i ???)

What should i save them as to sell to the punters as a jpeg ...they can take the shot to a printer & get it sorted to their own printer but im wondering what the optimum saving point settings are.

gluwater

They are fine as they are Gus. No need to change anything. Their printer can re-size them for whatever size output they want. The size you have it now you would have an 8x10 at 300dpi. Save yourself the work and leave them as is.

gus

gluwater wrote:

They are fine as they are Gus. No need to change anything. Their printer can re-size them for whatever size output they want. The size you have it now you would have an 8x10 at 300dpi. Save yourself the work and leave them as is.

Thanks GW but i dont mind doing the work again. I only processed about 100 shots out of a possible 950 on this setting.

I want them to be able to be blown up to at least A2 (17" x 22") So i am going to start again but need to kick off on the right foot & find out what is the best setting to do the lot with.

DavidTO

Gus, as long as you're saving all the original pixels, it doesn't matter what the dpi is. Really. All you need is the pixels. You could have 1 pixel per inch.

gus

DavidTO wrote:

Gus, as long as you're saving all the original pixels, it doesn't matter what the dpi is. Really. All you need is the pixels. You could have 1 pixel per inch.

All i need is the pixels but just 1 will do ? Thats sort of contradictory to me mate.

I need that smiley of a little head scratching his chin with a confused look.

soooooo....is the above 72 DPI savings ok for a 17" x 22" print. Why wouldnt it be better if i saved the shots at 500 DPI ?

Mike Lane

Gus if you're dead set on changing the DPI (as others have said it doesn't matter) you can do it without making any affect on the image at all by going to Image > Image Size and then deselecting "resample image" and then change the resolution to anything you want. It seems that 300dpi is sort of standard when it comes to prints and such, but really I don't much know.

DavidTO

Your shot there is 2336x 3504. That's all your pixels. If you ended up with 1 pixel per mile, you'd still be fine, you'd just end up with a doc that was 2,336 miles by 3,504 miles. The computer doesn't really care in this instance, it just needs all the pixels to reassemble the picture.


There are times when you will care what the dpi is, but really, right now it doesn't matter.

DavidTO

Humungus wrote:

soooooo....is the above 72 DPI savings ok for a 17" x 22" print. Why wouldnt it be better if i saved the shots at 500 DPI ?

Gus, it's like you've put gas in your tank, and you're all worried about the ratio it gets mixed with air. Let the engine worry about that. Just keep on driving.

Mike Lane

A monitor only knows pixels, it doesn't know inches or centimeters so if you had 1px per inch and you had 1000 pixels across, your image would only take up 1000 pixels on the screen no matter what. What's more, the printer knows how to adjust your image to make it so that it isn't 1 pixel per inch but the right ppi for the particular print job. Point is, you can just ignore it.

R Johns

Gus,

I'm no expert, (at anything ). However, all of the advice about "a pixel is a pixel" is true. I guess the most important thing to keep in mind is that , the more you up-sample or down-sample an image, the more loss to your original's resolution you'll get.

If you're not resampling the image (as I notice it's checked, in the bottom of the window) then you're okay. I'd just leave it alone. That way, the image only gets resampled once, when it hits the printer.

If you know what the dpi is, on the printer that you are printing to (smugmug gives you this info for their printers), then you would probably be best to resample to that dpi in PS or another program, like Qimage (for the print size that you're trying to get), because (I've read) that a printer usually does a worse job of it.

Take care...

Russ

Mike Lane

R Johns wrote:

because (I've read) that a printer usually does a worse job of it.

This is not true with EZPrints. They are much better at upsampling than any home user would ever be apparently.

But I'm not sure Gus is doing this for printing done through smugmug.

R Johns

Mike is right...

Maybe I could make a distinction though, as I believe that we both have good points. When I mentioned "printer", I was referring to the software of an actual printer. As I read Mike referring to a "printer", I believe that he is referring to a print company, such as EZ Prints (I'd be willing to bet that EZ Prints does a good job, too).

I would think, that they still control the resampling, prior to running it through their machines (via some special software, like previously mentioned), but I wouldn't trust Walgreens to do that.

Regards...

Russ

David_S85

Gus, a high resolution shot is all that is needed. You have those. That's what your 20D does. The dpi number is only an internal tag in the file header, which means almost nothing in the real world. Yes, it can be redefined, and the others are correct; those doing the output will know what the final print size is, deal with it, and your prints will be fine.

No information is lost or gained no matter what the dpi number is in the file header.


(in the following example I will use dpi and ppi interchangably)

Here's an example. I shoot a photo that's 3,000 pixels by 2,000 pixels. Then I edit the heck out of it, and don't resize or crop it at all. It will still be 3,000 x 2,000. Unless I change the dpi figure as I'm saving it, the data will still read 72dpi. I can tag it at 5 dpi or 420 dpi, and the number of pixels across and down will still remain at 3,000 x 2,000. That doesn't change.

Now if I wanted to place that same picture in MS Word, then it begins to matter. Tagged at 300 dpi, as I'm importing it onto the page, it will probably fit right away. If instead I had tagged it at 25ppi, the picture will appear on screen so large that I'll be hunting for the corner handles so I can resize it until next week.

I'm not sure how it works in PS, but in PSP I can just alter the ppi figure (called incorrectly "dpi") independently so the pic imports at whatever number of inches across I wish it to.

When I print at home, any good print driver, at its simplist, will ask me what the final output size in inches or centimeters should be. It then does the math internally and prints the photo at the X-number of ppi's required.

Art Scott

I may have missed this in the previous posts but......Gus......When you to to image > image size > deselect resample...but do make sure to constrain porportions.....

My local Pro Lab (DOUGLAS BLACK & WHITE IMAGEING) laid it out like this...my 6 mp camera (3008 X 2000 pixels) would produce a great 30 X 40 inch print if every one involved remembered to view it at the proper distance....every size print or painting has a proper viewing distance.....now I was a little concerned about my client so I went 1 step farther........I took my 72 dpi image and resized to 300 dpi (approx 8 X10) and then went to my trial version of Genuine Fractals and upsized to 30 X 40 inches (all of this is done prior to sharpening) and !!!VIOLA!!! I turned out an 30 X 40 that could be viewed from a fewinches and no pixelation or grainyness or noise.......

Unless you want huge...just save your files in their native 72dpi and don't worry any good reputable lab'd ripping software will fix it....some like my local even states not to sharpen as they will sharpen it before printing.

Less work for you means more play time.....:D

gus

Ok..i think i have it.

To gusilate...10 dpi @ the size of a house is the same as 20000 dpi on a postage stamp...its still the same photo. As the printer changes the size of the photo ordered ...so to will the dpi change acordingly automatically to suit.

How'd i do ?

Mike Lane

Humungus wrote:

Ok..i think i have it.

To gusilate...10 dpi @ the size of a house is the same as 20000 dpi on a postage stamp...its still the same photo. As the printer changes the size of the photo ordered ...so to will the dpi change acordingly automatically to suit.

How'd i do ?

Plus if you need more DPI than exists in your photo, the printer (pro printer like EZprints) will uprez it for you better than you could do yourself.

marlof

EZPrints, sharpening and uprezzing
Ok, so now I'm late to the game in this thread, but there's one thing that I still don't get, and that's the sharpening that's involved.

I've understood that in general sharpening needs to be done as the final step, after resizing etc.

But... when I prepare images to be printed at EZ Prints through my account, I usually never bother to resize anything (I don't look at the DPI etc), I just leave the file as be. But I also understand that EZ Prints doesn't apply additional sharpening when you use my preferred True Color setting, so I assume I have to do my sharpening locally.

Since I never could get a real grasp on USM (in spite of Rutt's excellent efforts), I went with Photokit Sharpener by Pixel Genius, since I liked what I saw. It has a three stage sharpening process (assuming you have no in camera sharpening): capture sharpening, optional selective sharpening, output sharpening. They advise (like everyone else) to first make sure your final image is its output size, and then apply sharpening. But, this contradicts the idea that I should let EZ Prints take care of sizing etc.

So I'm at a loss.

What I do now is: apply capture sharpening. Do other Photoshop stuff, like levels, curves etc if necessary. Apply output sharpening (the Contone setting closest to the printer EZ Prints is using). I then upload the file. I never touch the size or DPI settings along the way. Can I assume that the printing of diverse sizes will be ok? I mean, as long as there doesn't need to be done any real uprezzing and stuff? Or even then? Or should I change something in my workflow?