Sandy, I restored and blew up 75 photos for the Fountainhead Antique Auto Museum. Some from postcards. The display versions of some of the prints are 72 x 48 inches. Assuming you have reasonable expectations, it just a matter of patience and Photoshop.
A high end scanner is the best tool to start. The target should be 4000 dpi. There's little point in higher resolution because that's all the data there is to scan. From there, it's experimenting with PS interpolation.
OK, now I am really baffled. If the photographer has the original image, how can either photographing or scanning a "smaller print" of it produce a higher quality image than you would get from the original file? Is this a case where the digital file was lost, and there is nothing but the "smaller print" left to try to reproduce and enlarge? How could a scan from a small print produce better results for a 20"x30" blow up than using even a 4MP (just guessing number of pixels) digital file?
I'm with Wayne on this one... printing out the original file could not have improved the information the original file contained. So starting from the file would always be preferable.
Now, if this isn't a digital file, and odd machinations or lots of dodging and burning and darkroom work were already done to it, then perhaps it would be worth scanning the smaller image.
Hmmm? Sandy didn't say how big the 'small' print is, so it's tough to say how large a good quality print (150 dpi or better)could be made from a scan of the original. A high end flatbed scanner such as Creo, at the hands of a skilled operator, could make an excellent file at 4000 spi, assuming the original is of high quality. If the print is 8x10, that gives a 32000x40000 px file, or 128 MP. This would blow any camera file out of the water.
So, Sandy, what is the size of the "very good smaller print" your friend wants to reproduce? If we know this we can see what kind of quality, in print dpi, to expect at 20x30.
The original resolution was 4 MP or something from his old digital, and the file is available The print he has also is quite good at 8x10.
Should have given this infro first, I guess.
The 20x30 does not have to be spectacular quality, just reasonable.
Thanks, guys -
Sandy
Hi Sandy
I have a print from a 6MP file from a Canon 10D, cropped to pano, and printed at 14" x 36". Uprezzed in PhotoShop to 360dpi resulted in a 65MP file (12960 x 5040). The resulting print is quite acceptable. Your friend should be able to do something similar. Seems like it should do at least as good as a scan of a print made from the original file.
Sandy,
Glad to hear your friend still has the original digital image. Buck's experience shows what can be done with a digital image using good processing techniques. The experience that LF photographers have with scans does not work quite the same way with "small format" images. I am sure that some wonderful technicians seem to work magic with scanners because producing a pleasing image is part art and part physics. However, when your starting point is a postage-stamp size image (in your camera), and the end point is a large print, the laws of physics are the overwhelming limiting factors (assuming you want to reproduce original detail rather than create a more abstract painting-like print). Just remember that your idea of shooting a 36 MP image of a print is actually very similar to scanning a print; they are both nothing more than digital copies of some ink (or photo-chemical) blobs on a piece of paper, and that piece of paper did not increase the amount of detail in the postage-stamp-size collection of pixels, it just made those little blobs bigger. Think of it like making a macro shot of a cartoon in the Sunday funnies. Blow it up, and you will see collection of colored dots. The main difference between those dots and your friend's 4 million pixels is a matter of scale. If that were not the case, we would not have to pay thousands of dollars for DSLRs to make big prints of what we shoot; we could just crop prints from our point and shoot cameras and scan them. Having said that, a print does not have to be 150+ dpi to look good from a normal view distance, so those 4 million pixels taken from nature should look pretty good on the wall -- probably better with a lot less effort and expense than 100+ million pixels taken from a piece of paper with colored dots.
Posted by rob ashcroft on July 10, 2012 at 6:06 AM
If you have the original digital file then why not just upsize it to 30x20? This video shows you how to do it, including the 5-10% method, which is supposed to work better than doing it in one single pass. http://www.youtube.com/watch?v=nMqHOfeUHmo
I just tried it myself, as I was watching a training tutorial about this the other day. I took an old image from a Canon 350D (6MP camera) which was 6MB on file size. After upsizing using 10% increments it was 22MB and the physical size was 30x20 inches. On the screen grabs below are the original full shot, a zoom-in of the wooden handle on the far right of the shot from the original (not upsized), and finally the same zoom-in of the upsized version. Obviously, I had to zoom in more on the screen in Photoshop for the original to get the same screen fill. But you can see, I think, that not only is the upsized version as good, it's actually better is some areas - notably the wire strands behind the handle which are more well defined than on the original. You need to make sure you use 'bicubic smoother' not 'bicubic sharper', but apart from that it's quite straightforward. The reason the video talks about Alamy is that the agency wants larger image sizes in case the images are printed larger - which is what you want to do.
Finally, a little tale about pixel-peeping. The other day my wife said to me 'You know, I really like that shot of yours in the hall...'. There was a very long silence (from me). I couldn't remember, despite walking past it several thousand times in the past few years, what the picture was. I had to think about it. I actually went to look. The idea that people go up close to a photo on a wall and pixel peep always sounds worrying - but how many people actually do it? I do, but then I'm a serious photographer. Most people don't.
See this page from West Coast Imaging, in the left column, click on the Megapixel to Print Size Chart link. The chart will give a good idea of the print quality one can expect for a given MP image size.
Just one more note... I've had mixed results with whether or not upsizing in small increments is better. In general, I'd say it's not, and Adobe actually modified their Bicubic Smoother algorithm to avoid issues people used to see when doing it in one large step.
Right now, if someone is using PS CS3 or higher, I'd say just upsize in one shot first and see if you like the result.
Lots of really useful info in this thread - thanks to all!
I'm going to re-title the thread so those using the Search Engine for re-size/scanning info will find it.
Sandy
Sandy, good and interesting topic. Can't add much, but thought I would toss in a concept that seems to be missing - or at least I've missed it in the comments that I didn't read all the way.... ;-)
Of course this came from the film days, but is still valid today. And that's the idea of "original," 2nd generation, 3rd generation etc. With each successive copy or generation, there is a loss of data, quality, etc. I used to have 70mm dupes made from my 4x5's. Expensive and good quality, but it's a second generation copy. Transfer that to your scenario, and that print is a 2nd generation copy of the original data. There is physically NO WAY to scan no matter if you used a NASA scanner (ok, getting carried away) that you can re-create the original data that was lost in generating the little print. You can certainly get a high quality reproduction, but it will be nothing more than a 3rd generation print. Good processing and printing from the original file will produce a 2nd generation print, which by definition will be of higher quality than any 3rd generation print.
Discussion
15 repliesHe has an older fairly low-resolution image that a place wants to buy a 20x30 of. He has a very good smaller print from a custom lab.
He wonders what would happen if I took a picture of the smaller print with my D800 and blew THAT up.
Would this work?
Thanks for any thoughts -
Sandy
This sounds like a job for a high-end flatbed scanner at a reputable service bureau.
--P
A high end scanner is the best tool to start. The target should be 4000 dpi. There's little point in higher resolution because that's all the data there is to scan. From there, it's experimenting with PS interpolation.
Email me if you have questions.
4000 spi (dpi) should work nicely.
--P
Sandy
Now, if this isn't a digital file, and odd machinations or lots of dodging and burning and darkroom work were already done to it, then perhaps it would be worth scanning the smaller image.
Any detail on what the original is, Sandy?
So, Sandy, what is the size of the "very good smaller print" your friend wants to reproduce? If we know this we can see what kind of quality, in print dpi, to expect at 20x30.
--P
Should have given this infro first, I guess.
The 20x30 does not have to be spectacular quality, just reasonable.
Thanks, guys -
Sandy
I have a print from a 6MP file from a Canon 10D, cropped to pano, and printed at 14" x 36". Uprezzed in PhotoShop to 360dpi resulted in a 65MP file (12960 x 5040). The resulting print is quite acceptable. Your friend should be able to do something similar. Seems like it should do at least as good as a scan of a print made from the original file.
Glad to hear your friend still has the original digital image. Buck's experience shows what can be done with a digital image using good processing techniques. The experience that LF photographers have with scans does not work quite the same way with "small format" images. I am sure that some wonderful technicians seem to work magic with scanners because producing a pleasing image is part art and part physics. However, when your starting point is a postage-stamp size image (in your camera), and the end point is a large print, the laws of physics are the overwhelming limiting factors (assuming you want to reproduce original detail rather than create a more abstract painting-like print). Just remember that your idea of shooting a 36 MP image of a print is actually very similar to scanning a print; they are both nothing more than digital copies of some ink (or photo-chemical) blobs on a piece of paper, and that piece of paper did not increase the amount of detail in the postage-stamp-size collection of pixels, it just made those little blobs bigger. Think of it like making a macro shot of a cartoon in the Sunday funnies. Blow it up, and you will see collection of colored dots. The main difference between those dots and your friend's 4 million pixels is a matter of scale. If that were not the case, we would not have to pay thousands of dollars for DSLRs to make big prints of what we shoot; we could just crop prints from our point and shoot cameras and scan them. Having said that, a print does not have to be 150+ dpi to look good from a normal view distance, so those 4 million pixels taken from nature should look pretty good on the wall -- probably better with a lot less effort and expense than 100+ million pixels taken from a piece of paper with colored dots.
I just tried it myself, as I was watching a training tutorial about this the other day. I took an old image from a Canon 350D (6MP camera) which was 6MB on file size. After upsizing using 10% increments it was 22MB and the physical size was 30x20 inches. On the screen grabs below are the original full shot, a zoom-in of the wooden handle on the far right of the shot from the original (not upsized), and finally the same zoom-in of the upsized version. Obviously, I had to zoom in more on the screen in Photoshop for the original to get the same screen fill. But you can see, I think, that not only is the upsized version as good, it's actually better is some areas - notably the wire strands behind the handle which are more well defined than on the original. You need to make sure you use 'bicubic smoother' not 'bicubic sharper', but apart from that it's quite straightforward. The reason the video talks about Alamy is that the agency wants larger image sizes in case the images are printed larger - which is what you want to do.
Screen grabs http://www.robmarshall.net/photos/i-QxQFRZG/0/X3/i-QxQFRZG-X3.jpg
Finally, a little tale about pixel-peeping. The other day my wife said to me 'You know, I really like that shot of yours in the hall...'. There was a very long silence (from me). I couldn't remember, despite walking past it several thousand times in the past few years, what the picture was. I had to think about it. I actually went to look. The idea that people go up close to a photo on a wall and pixel peep always sounds worrying - but how many people actually do it? I do, but then I'm a serious photographer. Most people don't.
WCI Print Lab Info
I hope this helps
--P
Right now, if someone is using PS CS3 or higher, I'd say just upsize in one shot first and see if you like the result.
I'm going to re-title the thread so those using the Search Engine for re-size/scanning info will find it.
Sandy
Of course this came from the film days, but is still valid today. And that's the idea of "original," 2nd generation, 3rd generation etc. With each successive copy or generation, there is a loss of data, quality, etc. I used to have 70mm dupes made from my 4x5's. Expensive and good quality, but it's a second generation copy. Transfer that to your scenario, and that print is a 2nd generation copy of the original data. There is physically NO WAY to scan no matter if you used a NASA scanner (ok, getting carried away) that you can re-create the original data that was lost in generating the little print. You can certainly get a high quality reproduction, but it will be nothing more than a 3rd generation print. Good processing and printing from the original file will produce a 2nd generation print, which by definition will be of higher quality than any 3rd generation print.
Lon