if a photo hasnt got copyright on the back, can i get it copied / blown up ?

Twenty years in the biz and ? doesn't have a clue.

The photo is still under copyright regardless of whether or not there is a label or stamp stating so on the back. If you copy it, you are infringing on the photographer's copyright and are liable for 150,000 US$ per incident. Isn't buying a few more cheaper?

Copyright marks are no longer required since 1989. Copyright is free, instantaneous and automatic when the photographer "authored" the photos. You MIGHT have purchased a "limited license", as part of your fees to the studio, but that would have been in your private agreement and we can't read it from out here. On the other hand, many people still put copyright notice on things as a "reminder" that they continue to claim the entire copyright ("All rights reserved"), unless you have a specific license. Removal of copyright notices are also worth another $25,000 in damages when violators are sued.

Not only would you be potentially liable for "actual damages" of your copyright infringement (e.g., payment to the original studio for the "larger copies", or for statutory damages of up to $150,000 if the photographer registered the copyright), the "cheaper shop" would also be sued, if not charged with felony copyright infringement crimes (i.e., intentional copyright infringement for profit). Why would they take the risk of 5 years in prison just so you can gyp your photo studio?

It doesn't take 20 years "in the business" to be able read the copyright laws, or at least google the rules.

Sad state that a self-employed photographer has to worry about criminals reproducing his or her photos without permission.

You need to check your contract or sales agreement, not us. According to the law, the photographer retains the copyright to all his/her photos. So by default you would be violating copyright law. That's why you need to check the terms of your agreement. It would have to say that all rights have been relinquished to you. If it says nothing, then you don't have them. The absence of a copyright notice is not the absence of a copyright. It's there the instant the shot is taken. So getting a print made without the permission of the photographer would be illegal, even if you get away with it. Some photo finishers won't print it if it looks like it was professionally done unless you have a release from the photographer.

Unless you have low standards for quality, an enlargement from a small print will not be very good.

The studio owns the copyright, whether or not there's a copyright mark on the photo.

Most places would send the photo back and tell you it's not legal to copy them.

Nope.

Copyright isn't something imprinted on the photo or in the meta data ... it;s something that you automatically get, in the case of photography, the very second you press the shutter release. You don't even have to register for it but it does help when claiming damages.

It's the persons who wants to use the image responsability to insure the work they are trying to copy isn't protected under copyright.

You'd still violate copyright since that stays with the photographer. But yes, it could be done

yes you can, as long as the name of the studio or photoghers name is not on the pic.