How large a print can I go??

[mwfair]

How do I know how large my digital prints can get before they become distorted? I'm trying to find an online photo lab that processes digital prints but would also like one that can enhance the photo if I want to go up to 20x30. Any idea's, help, labs that I should look at? Also, I currently shoot in jpeg format, should my shots be taken in RAW format if I want to go that big?

[Frog]

I use mpix and adorama for developing but don't know if they can or will do any enhancing other than color correction.
What camera? Pixel quantity(though 6 or more should do).
Are you doing any post processing? The final should be sharpened.
One thing that will give you an idea is to magnify your shot to 100% and see if it still looks good, though I'd guess that it it looks good at 33 or 50, you could still get a good 20x30 out of it.
I'm not an expert so I'd keep watching the thread for other advice.

[Franglais]

How do I know how large my digital prints can get before they become distorted? I'm trying to find an online photo lab that processes digital prints but would also like one that can enhance the photo if I want to go up to 20x30. Any idea's, help, labs that I should look at? Also, I currently shoot in jpeg format, should my shots be taken in RAW format if I want to go that big?

They won't become distorted. They will appear to be less sharp and and pixelated after a while - if you go up and bury your face in the image. Normally the larger the print the further the viewing distance.

Optimum MPix for a given print size are as follows (source = Chasseurs d'Images). This means that if you do an A3 size print from a 24Mpix camera you probably won't see any difference compared with a 12Mpix camera

12MPix = A3 = 12x16.5 inches
24Mpix = A2 = 16.5x23.5 inches

Give the lab a JPG-fine file. Don't try to do any special preparation yourself (sharpening) - leave it to the lab.

[Frog]

I don't know, Charles. I think you can print much larger than 12x16.5 with a 12 MPx camera. I've printed larger with 10MPx and even if I bury my face in it, I need a magnifying glass to pick out any fuzzy bits.
The cost of printing is relatively low.....just print it and see what you get.

[mjs1973]

I have printed & sold a 20x30 print taken with a 6mp camera. The quality of the image file will have a lot to do with what your final results will be.

I use Mpix.com for almost all of my printing. Their general rule is 100 pixels = 1 inch. So if you want a 4x6 print, you need to upload a file that is at least 400x600 pixels wide. For a 20x30 print, you would need to upload a file that is at least 2000x3000 pixels.

[Franglais]

I don't know, Charles. I think you can print much larger than 12x16.5 with a 12 MPx camera. I've printed larger with 10MPx and even if I bury my face in it, I need a magnifying glass to pick out any fuzzy bits.
The cost of printing is relatively low.....just print it and see what you get.

I was copying directly from Chasseurs d'Images, a French magazine which I trust (number 1 in Europe). They were doing a comparison of the Nikon D700, the Canon 5DMkII and the Sony A900. They say that the maximum number of pixels usable by inkjet print is about 256 pixels per inch. If you have more the extra information is lost. If you have less (your case) then you may notice a difference compared with a camera with more pixels but not in normal viewing. If you're talking about a print on classic silver halide colour paper then the resolution is much less.

BTW the result of the comparison was - the D700 beat the others almost every way except for resolution and they had to go to an A2 print to see a difference.

[Ron Kruger]

Hey Franglais,
Wouldn't the original sharpness of the image also make a difference, and the quality of the glass that produced it?
I do all of my shooting for repoduction in magazines, and I learned long ago that original sharpness is a very critical factor.
I also wonder if d'limages wasn't computing their sizes according to magazine style reproduction? That's not the same as prints, because through the processes of printing with full web and even offset presses, you lose a lot. (I've also worked as the editor of a four-color magazine.)
Anyway, I have a question for you.
I haven't messed much with prints, but I recently met this fellow who wants me to cover the walls of his lodge with pictures, mostly 8X10s, but with a large centerpiece for each theme.
I'm shooting 14.6 MP and will only use my best shots for the larger centerpieces. How large would you say I could go for these centerpieces?

[Franglais]

Hey Franglais,
Wouldn't the original sharpness of the image also make a difference, and the quality of the glass that produced it?
I do all of my shooting for repoduction in magazines, and I learned long ago that original sharpness is a very critical factor.
I also wonder if d'limages wasn't computing their sizes according to magazine style reproduction? That's not the same as prints, because through the processes of printing with full web and even offset presses, you lose a lot. (I've also worked as the editor of a four-color magazine.)
Anyway, I have a question for you.
I haven't messed much with prints, but I recently met this fellow who wants me to cover the walls of his lodge with pictures, mostly 8X10s, but with a large centerpiece for each theme.
I'm shooting 14.6 MP and will only use my best shots for the larger centerpieces. How large would you say I could go for these centerpieces?

Chasseurs d'Images was targeting an inkjet print as final product. The inkjet printer may output 4000 dpi in 8 colours but finally they say it can only resolve about 200-300 dpi. The standard resolution for printing in books and magazines is about the same (300dpi).

Your 14.6Mpix image would be perfect on a A3+ size print (13x19 inches). Go from the 8x10 to the 13x19 and they would appear to have the same defiition. If you go larger then you might notice that the big print has less definition than the 8x10. However you would have to stand up really close to see it. The larger the print the further away you stand to view it.

Yes I think that to get the most of these very high Mpix cameras you have to have the best lenses and probably a tripod as well.

[Ron Kruger]

Thanks, Charles. People will be viewing, at least initially, the poster-sized prints from a distance of a dozen yards or so, but I suppose they will be viewing it closely as well.
I just learned today that one of his clients (a big, Chicago construction firm) has agreed to print my pix on what they called their "poster printer," and I presume this means something more sophistacated, with much higher dpi capabilities, than an ink-jet, and maybe something better than one gets from Snapfish, Shutterbug or even Kodak.
Since I don't have much use for a printer, all I have is a cheap HP ink-jet, bought mainly to print letter and such. I think it cost me only about $90 at WalMart. But I've found it makes surprisingly sharp 8X10 prints with dense color saturation on Premimum+ photo paper (quality of paper also plays a major role), set at "Best" print quality (really drinks the ink, however), so I'm pretty confident my images will look good at much larger sizes produced on a professional quality printer.
We'll see, and I'll keep you posted, if you're interested.

[Photo-John]

The kind of calculations Chasseurs d'Images is using are really for people who don't do any post-processing. I've sold 4 and 6-foot tradeshow images shot with 4-megapixel cameras. Sure, your images will get softer as you enlarge them. But is that really a problem? I don't think so. I would be comfortable going to 5 feet with your 14-megapixel camera. Will you be able to walk up and look at it with a magnifying glass? No. But it will still look good if you set it up right. I generally set my resolution for print images at 250 dpi at the final print size. I have no qualms about doubling the resolution in Photoshop. If you're concerned, set up a file at the size you want to print, and then print a couple of sections on your inkjet printer and view them from a reasonable distance. The general rule for viewing distance is twice the diagonal of your image.

[Greg McCary]

I am not so sure it is all about Mpix's. When I upgraded from the E-510 to the E3 I noticed an improvement in IQ. The cameras have the same Mpix size but there is a noticeable increase in fine detail in processing and in prints. So I think the type sensor you have also figures into the equation. I think most all DSLR's are going to out perform high Mpix P&S cameras due to sensor size and quality. Sensors quality is a important as Mpix size. Also when I had the E510 an I upgraded from the kit lens to the 14-54mm mid grade lens there was a slight increase in print quality there too.

[Ron Kruger]

Thanks, John. Most of the publications I deal with specify a file that is at least 300 dpi. I've sort of settled on 400 dpi in PS, cropped at 5x7, because that gives me a file of about 4 or 5 MB, which I can email. My original low-compression JPEGs are around 10 MB, which is too large to email, and an 8x10 at 400 dpi is a little over 10. I save my better shots on my camera's memory card, so I can send originals, or process them at a larger size and dpi and put that on CDs to send to them, if needed, and I've mentioned that to all of them. So far, since going digital last June, none of them have requested larger files, and I've had three 8x10 covers published from these 400 dpi, 5x7s, and they look fine.
I have cable for my internet connection, which is many times faster than DSL, so it doesn't take long to load and send these files, and I'm considering bumping up the dpi to 500 or even 600 at 5x7, because I'll still be well under the 10 MB email limit. Won't hurt.
I'm still on a learning curve concerning digital technology and how it all relates to the printing industry.
Greg: I've heard this before about sensor size, but I'm not sure what's big and what's not. My specs say that I have 14.6 million effective pixels and a CMOS sensor that is 23.4 x 15.6 mm. How does that compare?
And maybe you know what this means: It also says I have 15.1 total pixels? And 1.5 FOV crop? I presume FOV is field of view, but the crop throws me? Is this the part that makes a 200mm lens equivelent to a 300 in film?

[Greg McCary]

Greg: I've heard this before about sensor size, but I'm not sure what's big and what's not. My specs say that I have 14.6 million effective pixels and a CMOS sensor that is 23.4 x 15.6 mm. How does that compare?

Check the link and scroll down and compare what you have. I used the 4/3rds sensor which is about as small for a DSLR as it gets. I have printed shots from the E510 as big as 20x24. It turned out pretty good. I have only gone as big as 11x14 with the E3, so far. Same size sensor but a good difference in quality as far as I can tell.
http://en.wikipedia.org/wiki/Digital..._reflex_camera

[brmill26]

On print size, if you're wondering, just contact the printer you're going to use and ask them. They see hundreds of prints a day; I'm quite sure they could tell you very quickly what will and won't work.

I've printed a slightly cropped 10.1MP image at 20x30 via El-Co labs. It was shot with my 70-200 F/4 L and was extremely sharp, but it easily could've been printed larger. The resolution on the photo, even "under the magnifying glass" is absolutely amazing. So I'd say you could easily go larger than 24x36.

Also, most people (myself included) prefer to do all their post-processing before sending it to the printer. That way, you make all the decensions and you control the look of the photo.

[PhotoRookie]

I print A3's all the time, images from a 30D (8.2mp). Prints from professional labs look better than ones I print at home but both are sharp. I have also printed 24 x 36's on an Epson 7600 and the images still look very sharp.

[Ron Kruger]

Thanks, everyone. I'm feeling pretty confident.
And, Greg, thanks for the link. After some reading and flipping through pages, I now have a good understanding of sensor size, but also of other aspects (beyond pixels) that control image quality.
I think I've made a good choice with this Pentax K20D, but will make an even more informed choice on my next camera, because although I like this camera and love the 200mm lens, I'm not happy with the company, Pentax.

[Franglais]

I just learned today that one of his clients (a big, Chicago construction firm) has agreed to print my pix on what they called their "poster printer," and I presume this means something more sophistacated, with much higher dpi capabilities, than an ink-jet, and maybe something better than one gets from Snapfish, Shutterbug or even Kodak.

From what I've seen at trade shows, many of the "one-off" poster printers are inkjet, the same technology as in the A4 and A3 printers we use at home. All they have to do is to increase the width of the thing to take the paper - or whatever support they choose to use.

Offset printers have been used for decades for billboard hoardings but they usually make the image in smaller rectangles which the guy pastes up to make a whole.