20X30" prints

Ed911

Quick question. A friend needs to have some 20x30 inch prints made. SmugMug says that 80 or 100 dpi is fine for this size.

If you have esperience with prints made at this or similar sizes, I'm looking for your comments. Please don't point me to SmugMug.

Have you used the recommended dpi? Were you happy? What did you think about print quality? etc.


Thanks,

urbanaries

Ed911 wrote:

Quick question. A friend needs to have some 20x30 inch prints made. SmugMug says that 80 or 100 dpi is fine for this size.

If you have esperience with prints made at this or similar sizes, I'm looking for your comments. Please don't point me to SmugMug.

Have you used the recommended dpi? Were you happy? What did you think about print quality? etc.


Thanks,

I've had several 20x30s printed and mounted through WHCC and was pleased with the results. I just upload as high res files as I can (~4000x3000 pixels)and don't fret too much about the dpi.

arodney

100ppi for output is real low! I would be hard pressed to send less than 180-200ppi to any contone device.

If you've got a clean, digital file from a good capture device, you can easily go 200% in interpolation, then sharpen appropriately and maybe add a tad of photo grain.

Art Scott

Ed911 wrote:

Quick question. A friend needs to have some 20x30 inch prints made. SmugMug says that 80 or 100 dpi is fine for this size.

If you have esperience with prints made at this or similar sizes, I'm looking for your comments. Please don't point me to SmugMug.

Have you used the recommended dpi? Were you happy? What did you think about print quality? etc.


Thanks,

I normally change my dpi to 300 in photoshop and then run that file into Genuine Fractals (now at 5.1 I think) and uprez to my large size (20 x 30 up to 40 x 60 so far) and have printed at Douglas Photographic Imaging here in Wichita.....the reason I use them is not only are they local but they work very closely with Aircraft (Aerial) Photographer Paul Bowen ......I have never had a bad print from them in over 25+ years...they will also do ftp if you want to upload to them....

LiquidAir

I have made one 20x30 print through SmugMug. The original was a full frame image (no cropping) from a 5D taken very carefully (I took 3 on a tripod with MLU and chose the sharpest one to process and print.). I sent the whole file to SmugMug for printing which meant printing at around 140ppi. Overall, the print looks very good from any kind of reasonable viewing distance. However, if you "pixel peep" the print you can see some softness comared to higher ppi prints. I mounted it over a couch where it is difficult to get close to and it looks fine. If I was hanging it where people could easily put their nose on it, I'd print it smaller. Generally the largest prints I make from a 5D are 16x24 and more often 14x21 (so I can use 17x22 cut sheets).

As for printing in the 80-100 ppi range, I guess it would depend both on the particular image and what I planned to do with it. For close viewing of images with fine detail I usually consider 180ppi to be a minimum and 240ppi to be preferred. However if you are printing large for an image meant to be viewed from a distance, a lower resolution is certainly reasonable.

pathfinder

I have a print of this frame and this frame at 20 x 30 inches in my office. Both were printed by Smugmug( EZprints ) and are viewable with your nose to the print. They are virtually grainless, and you can see individual grains of sand falling in the light beam in the first shot. Their dimensions, in pixels, taken from the exif data in the gallery, are 3156 x 4734, and 3328 x 4992, both shot with a 1DsMkII. These numbers yield 157.8 pixels per inch for the first image, and 166.4 pixels per inch for the second.

I spoke to Andy about uprezzing these before printing, and he said to let the lab do it, that they could and would do it better. They must have.

The current version of Genuine Fractals is now 6.0, Art, which I do use when printing large images of my own on my own printer.

At Marc Muench's print workshop, he suggested 180 ppi is acceptable for large prints ( > 30 x 40 inches ) as they are usually looked at from a larger viewing distance.

It is good to keep in mind, that 240 pixels per inch, does not mean 240 dots per inch for a print from a fine art ink jet printer, as the printer will print many dots of ink for each single pixel.

Smugmug MAY be able to print large prints at 80 ppi, but I don't think you will get optimal quality at home if you try to print with this low a pixel count with your own printer.

The other factor is the quality and the type of image that you are printing. Lower pixels per inch may work fine for a low contrast, ethereal soft focus portrait, but will be very poor for a finely detailed landscape full of billions of tiny leaves of fall foliage.

I have a 17 x 22 inch print from about 1/5th of a frame from a 40D shot at ISO 800 of a deer, that I really like. I uprezzed it with GF 6.0 and printed it 17 x 22 inches and I think it looks great. It is grainy - hey it was ISO 800 - but it is razor sharp and I think it holds up well. Can I routinely make 17x22 in frames from a hand held 40D shot - heck no, but once in a while, I do have some luck on my side. ( 500mm handheld, 1/250th f8 IOS 800 ).

My deer shot started at 2354 x 1576 pixels ( 1576/17 = 92 ppi, and the 2354/22= 107 ppi ) and ran through GF 6.0 The print was printed by my own Epson 3800. Way below the standard 240 pppi or 360 ppi typically recommended. The shot IS grainy - I said that. If you look closely you can see the grain. But no one who has looked at the print has said it is too grainy, they go wow, how did you get that close!?

If the shot were not sharp, I don't think it would fly. One must start with a technically very good quality image for larger prints.

I think Urbanaries said the same thing I did in lots less words

arodney

You don't need expensive and exotic software for this, Photoshop can do it just fine:

http://www.digitalphotopro.com/technique/software-technique/the-art-of-the-up-res.html

Where GF comes in real handy is taking really small original images, an excellent example being microfilm scans, sizing them up huge (wall size). Mac Holbert at Nash editions did just that and in this kind of example, he found GF far superior. Going a few hundred percent, try Jeff's technique.

pathfinder

I loved this comment from the opening page of that link, Andrew

" Cheap lenses, camera shake, bad exposures leading to noisy images and poor camera composition, as well as radical cropping, won't lead you to nirvana. “CSI” is a nice TV show, but stuff that's soft, out of focus or noisy will remain that way, only bigger, when you up-res in real life. A tripod or fast shutter speeds and understanding proper digital exposure and cropping are critical. While post-processing can help, it can't eliminate technical defects."

And yes, he uprezzed with PS, but he sharpened and added grain with PhotoKit Sharpener. GF 6 includes a sharpening algorith of some sort too, now!

I have not felt the need to purchase Photokit Sharpener as I use what Adobe brings me!

I do agree that for modest uprezzing all one needs is Photoshop and Bicubic Smoother. I use it frequently.

arodney

pathfinder wrote:

And yes, he uprezzed with PS, but he sharpened and added grain with PhotoKit Sharpener.

Which is 100% Photoshop processing that you could accomplish exactly (if you knew the recipe).

To get a start on what's happening with sharpening:

http://www.creativepro.com/story/feature/20357.html

Then Bruce has an entire book on sharpening. You can build your own PKS (but do you have the time and media to do so)? The same with film grain.

Again, there's no need for exotics here. Photoshop can do the job. At least if properly driven.

pathfinder

I do capture sharpening in ARC, and output sharpening in Lightroom2 ( or I let Lightroom do it for me I should say)

arodney

pathfinder wrote:

I do do capture sharpening in ARC, and output sharpening in Lightroom2 ( or I let Lightroom do it for me I should say)

Which is all based on PhotoKit Sharpener. Adobe licensed the routines for v2. Before Bruce passed away, he completed most of the work, Jeff did the rest.

I'm doing the same, capture and most output in LR. But there's as yet, no creative sharpening in LR. Maybe in 3.0

Sam

Good answer Pathfinder.

Just a note: I have a 20X30 image printed with light jet printer, and I think it holds up well, with good detail.

The file was sent to the printer at 119 ppi.

But like Pathfinder said, if I were printing this at home I don't believe it would have come as well.

Sam

pathfinder

Sam, I strongly suspect the online printers uprez the files in some manner, but I do not have any real evidence, just a gut level suspicion. Not that I think that is a bad thing to do either. I just doubt they are printing large prints at 80 ppi, given a choice, and uprezzing is a easy way to avoid that.

jfriend

pathfinder wrote:

Sam, I strongly suspect the online printers uprez the files in some manner, but I do not have any real evidence, just a gut level suspicion. Not that I think that is a bad thing to do either. I just doubt they are printing large prints at 80 ppi, given a choice, and uprezzing is a easy way to avoid that.

In the end a printer can ONLY print at it's own native print head resolution. Since nearly all printers these days are way more than 80 dpi (often in the range of 240dpi), some software, somewhere in the chain is uprezzing anything that's printed that starts out at 80. If it isn't uprezzed before it's given to the print driver/engine, then it's the print driver/engine that does it.

So, in my book, the question is only around which software are you going to let do that task? Your own software, your printer's pre-processing software (if they do this) or the print driver/engine software?

Commercial labs are in the business of generating good looking large prints so I believe that their print driver/engine software is pretty good at the uprezzing and I've gotten good results without uprezzing myself. That said, there's nothing wrong with taking control of the process and uprezzing/sharpening yourself if you know what target resolution to be shooting for.

Sam

pathfinder wrote:

Sam, I strongly suspect the online printers uprez the files in some manner, but I do not have any real evidence, just a gut level suspicion. Not that I think that is a bad thing to do either. I just doubt they are printing large prints at 80 ppi, given a choice, and uprezzing is a easy way to avoid that.

Pathfinder,

You are right as usual. What I was trying to convey was if you have a good clean image, and you have less than the desired ppi at the size you want to print, you can still get a great print.

Obviously somewhere in the process little 1s, and 0s are zipping around, (well OK in my computer they kinda meander) doing their magic. But the magic works.

I may or may not up rez for a particular print I am doing on my printer, but my printer likes 600ppi.

Sam