how large can I print

[fotomatt780]

I have scanned a negative as an 18 megabyte tiff file. What is the largest print that I can get away with without noticable decrease in the quality of the image?

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[Big Mike]

Welcome to the forum.

There are quite a few variables so it's impossible to give a definitive answer. Was this from a 35mm neg or something bigger? The type of scan and the quality of the scanner will play a factor. A professional drum scan will probably give you the best chance for big enlargements.

Another factor is persoal...what is a noticeable difference to you? It may not be what someone else might think. What is acceptable quality to you? At what distance do you plan to view the image? Billboards look good and they are greatly enlarged.

The printing process will make a difference as well. I don't know much about that, but it's easy to figure out that a professional printer on nice paper will look much better than something printed on plain paper with a cheap home printer.

[fotomatt780]

Yeah, sorry I should have been more specific. First, it is from 100 speed 35 mm negative. I am not sure of the scanning process (I had it done by Foto1) and the printing I am doing is for my wife and some friends. It will be hung on the wall but not viewed really closely. A noticable difference to me in this case would be that from 2-3 feet away you could see pixelation, or tell that it wasn't very clear. I am just hoping to get about a 16 x 24 out of it. The reason I ask is because they told me that 8x10 was the very largest I could get, but I think they were just trying to get me to buy the next best scan that was $20 for one scan of the negative.

[Big Mike]

I'm really no expert but I know that you can get a good 16x24 print from a 6MP or 8MP digital camera...so at 18MB, there 'might' be enough information to get a crisp print.

The digital enlargement process will also play a factor. I think there is a software called 'Genuine Fractals' that is supposed to be the best for enlarging digital images.

Are you printing this yourself? I think the easiest thing to do would be to just take the negative to a good lab and get them to make the print. A good lab will do their best to make you happy so if it's not up to par, have them reprint it.

Another factor I forgot to mention is the quality/sharpness of the actual photo. A photo shot while on a tripod with a remote release and mirror-lock-up, will enlarge much better than a hand held shot with a slower shutter speed.

With that all said, it's mostly photographers and people who spend their time on photo internet forums that worry about small amounts of grain or pixelization. I have found that most other people just look at the photograph as a whole.

[fotomatt780]

Thanks a ton. It is a very crisp image, having been shot off of a tripod. I think I will just go ahead with the print at a 16x24 and see what happens. Thanks for your input. I work with film a lot but am new to digital processing, so this helps.

[etaf]

do you know what PPI it actually scanned at.
If you take it into photoshop (or other image editor) and see how many pixels it is Height and Width.
then for a general guide 300PPI for prints
so take the height pixels and divide by 300 same for width - this will give you a rough guide, some people have said you can get a good print from 150 PPI, the lowest I have achived an good A4 print from my canon printer was using 240PPI.

but nothing beats having a go and see

[Christie Photo]

Another "non-expert" here, but I believe you can expect the same results you'd get from the negative. An 8x10 image at 254 DPI if just about 15 mb, so the lab will increase the size of your file if you print larger than oh... 8 1/2 by 11.

Remember... when you enlarge the photograph, you enlarge all of it's shortcomings too.

[Rob]

Don't forget that a lab will only suggest what they can do themselves - if they're a small lab, they probably said 8x10 as it's the biggest their machine can do! See if there's a pro lab you can e-mail or ftp the picture to and ask them what they recommend.

I'd think you'll be fine - I often print using an HP printer at A4 from a 4MB file and once it's framed it looks great - it's tricky to tell it from "the real thing".

Lastly, it seems a bit silly to pay $20 for them to scan at a higher res considering that a pro lab will probably print with your corrections (cropping / dodging etc.) straight from the neg with traditional technique....

Rob

[Digital Matt]

The size of the file doesn't mean a thing. You can save that as a 2mb jpg, and it won't effect how large you can print it.

This pixel dimensions vs your dpi determine your print size. I'm assuming the file is 300dpi, so what are the pixel dimensions? You can bicubically resample images in photoshop to enlarge them quite a bit beyond the native resolution.

For a 16x24" print you need pixel dimensions of 4800x7200 @ 300dpi. I would say if what they gave you is 2400x3600 or bigger, you are fine.

[İAnderGraph]

ive been keeping a keen eye on tis thread, not because i can help but because i ave no idea either!

whats the biggest any of you guys have printed from a 20D? how would i enlarge its resoloution?

[etaf]

so the 20D is
3504 x 2336 pixels
so @ 300PPI
3504 / 300
2336 / 300
= 11.68" x 7.78"

but as you have seen it may be possible to get a good image at a lower resolution.

now there are a number of programs to enlarge photos -
genuine fractals is a great program.

[İAnderGraph]

12x8

thats teeenyyyyy!!!

i hope those applications work well

[etaf]

yea, but thats assuming 300PPI and you may be able to get away with a smaller PPI maybe 200, but the general rule of thumb is 300PPI

[İAnderGraph]

for reference this is what christopher bibbs (no idea but if your reading thanks chris!) says


Christopher Bibbs , jun 08, 2005; 12:26 p.m.
With a good upsampling program like GenuineFractals, the classic 27x41 should be easy to create. With just PhotoShop and bicubic sampling I've made clean 18x27 prints from studio shots that could have easily gone larger.

[etaf]

you may want to have a look at an image i have tried playing with GF
http://www.dpforums.com/forum/showthread.php?t=1306