Is interpolating (increasing dpi) image ever worse?

I had a pic that was slated to be the cover of a well known magazie, but when they cropped it down and, it wasn't quite 350 dpi at that full page size. So they were behind schedule and chose another image. Ouch.

My question is this, am I ever worse off if I use a tool like CS2 to add pixels to raise the dpi from 300 to say 350? In other words, is there ever a case where it would print WORSE?

I like to shoot my objects (tabletop shots with background paper, etc) with lots of foreground and background to allow editors lots of leeway when doing the layout and it has mostly worked out well for me. But when cropped in closer, the dpi of course goes down dramatically. I recently went from a 20d to a 5d to help this problem, but I still wonder about if increasing the number of pixels in software is ever a bad thing to do.

Anyone?

The magazine that thinks it needs 350 pixels per inch on their cover is foolish. Offset printing isn't that precise.

But if that's the level of ignorance you're dealing with, you may as well play their game. Upsize to your heart's content, to give them the pixels they think they need.

A couple things (I am sure you are aware of some of them so bear with me):
1) When you go from 300 to 350 ppi (you said dpi, but ppi is what you meant I am sure), either you have to reduce the size of the photo without resampling (i.e. downsizing), or if you upsample up to 350 from 300, the size of your photo will increase.
2) You are seeking to ensure that a certain size of your photo will be 350 ppi. I would determine the smallest area the client would crop to and ensure that size is what you upsample to in PS.
3) To upsample, you can use either PS, or Genuine Fractals, or other software. Genuine Fractals swears by their product that you will lose next to nothing with an 800% increase in ppi.

Hope that helps.
Pat

Curtis N wrote in post #3614653
The magazine that thinks it needs 350 pixels per inch on their cover is foolish. Offset printing isn't that precise.

But if that's the level of ignorance you're dealing with, you may as well play their game. Upsize to your heart's content, to give them the pixels they think they need.

Curtis hit the nail on the head here - someone, somewhere, decided to take the lpi*2 rule completely literally and never bend. It's silly - if you were in the ballpark, you're just fine.

He also hit the nail on the head with his second comment - I think you'd have been just fine sending them an upsampled revision.

To answer the original question, re-sampling is always a bad thing, whether up or down. Fortunately "bad" is relevant and depends on the image and intended use. Sometimes "bad" is pretty darn good. In the case mentioned here, we don't know how much was cropped, so impossible to say whether the resultant image would have been usable for the magazine cover. I doubt if an editor picky enough to toss an image that couldn't be printed at 350 ppi would accept something re-sampled at 800%, regardless of what Genuine Fractals claims. The OP says he always allows plenty of room for the magazine to crop his images, so apparently they have been routinely doing that. Therefore they must have the skill and knowledge to re-size the images to suit their needs. If so, why didn't they choose to do that for this one? Either there simply was not enough pixels left, or perhaps they just wanted another cover... My 2 cents.

Curtis N wrote in post #3614653
The magazine that thinks it needs 350 pixels per inch on their cover is foolish. Offset printing isn't that precise.

But if that's the level of ignorance you're dealing with, you may as well play their game. Upsize to your heart's content, to give them the pixels they think they need.

This is true with 99% of printers but offset printing is evolving very fast and will be making huge jumps in the next few years. Typical printers are using anything from conventional 175 to 240 line screens. The company I work for is one of about 15 nation wide that is using the sticatto method. The plates are output digitally with a laser, no more light tables or burning plates. We used sticatto 20 at first and are now using sticatto 10. The printed image is made up of millions of 10 micron dots that look like they are splattered on the sheet, no more screen patterns. Its hard to even see the dots with an 8x loupe, our pressmen now have lighted 12x and its still kind of hard to see dots. I personally think its overkill but some customers insist on the detail that sticatto provides. If you want to see an example most of the car manufactures are using this method on their brochures, pick one up and check it out under 12x then compare it to a typical magazine image. Youll be amazed by the difference. Our company won 18 awards at the 2007 Midwest PIA awards ceremony.

Headcase,

I work for a carton manufacturer and work with commercial printing companies on a daily basis. The evolution to computer-to-plate technology is a good thing for several reasons.

And as I'm sure you know, it's one thing to burn a plate with microscopic detail. It's another thing to lay ink on a piece of paper travelling at lightning speed through a web press while keeping four colors perfectly registered. Automotive brochures are printed to a different standard than magazines, and probably always will be. Economic realities and all that.

Headcase650 wrote in post #3615481
Its hard to even see the dots with an 8x loupe, our pressmen now have lighted 12x and its still kind of hard to see dots. I personally think its overkill.

This is really what makes the whole 350 ppi requirement ridiculous. Who reads magazines with a loupe? The purpose of the cover is to make it sell from the rack, and the customer will make that decision from 6 feet away.

I completely understand what your saying. And most of our customers dont have a clue. Going to this sticatto was a nightmare to say the least. For over a year everyone was pulling their hair out. We had to "fingerprint the presses a couple dozen times to get the gradient curves set properly and I think we've been through a dozen different types of blankets and ink formulas. Right now we have a Sheet fed 40" 6/1+coater Komori, a sheet fed 26" 5+coater Komori, they both run 10-14 thousand an hour, installing another 6/1+coater 40" Komori, a piece of crap Didi 17.5x22" web and a 4/4 royal zenith web. I realy love/hate printing sometimes but its the only thing Ive done for the last 15 years. Well that and photography one the side.