Viewing images to determine quality of print output

[ME100FINN]

LOTS of questions here...hope you can help!

I have been reading lots of threads on understanding DPI/PPI. I DO get it. It would seem the standard 300ppi is a rule to follow for a good crisp image printed on an inkjet. To be honest, i have never paid attention to the ppi ...gasp...on any of my print images and I have had great prints. But now I will!!

I am viewing images onscreen at 100% and they are fuzzy (raw or jpg) and I have a hard time editing these images--I dont know how to gauge whether or not the image is crisp enough to print, and at what size!

This is the deal...I have a Canon i9900. I have A3 paper and I sure would love to USE it, but I am scared!! I honestly dont know if any of my images with my 20D are crisp enough to make it to that size! What % range do I look on screen to determine whether a print will be sharp/crisp?? 100% or "actual pixels"??? Also, in order to get a 13x19 image print, the raw file tops at 179ppi. Is that enough??

I have printed a few 4x6 images recently on my Epson PictureMate and they turned out really nice. I dont want to waste tons of ink and paper on the larger prints until I am sure--ON SCREEN--that I have an image worthy of printing larger format (whether it is in focus to begin with and then if I applied enough sharpening, etc).

What method do you use to determine print sharpness (aside from ppi)? Say viewing 100% for larger images 8x10 and bigger? Say 25% for 5x7 and smaller? I have images that look fuzzy, but if printed smaller they are sharp.
HELP!
-
Beatrice

[Carbone]

Beatrice,

Images can contain zones of good focus and zones of blur (that's because of the depth of field). In order to know if your image is sharp enough, you can get back to your Canon software, there might be a tool to show you where the focussing point was. That is the area you should look at in PSE. If this is clear, then your picture is ok.

I have a 10D (you camera's older brother!) and I do have to a touch of unsharp mask to each picture because Canon camera images are alwasy too soft (Canon is very conservative, better be safe than sorry in other words).

179ppi is ok, especially considering the fact that this size (13" x 19") will most likely not be viewed up close.

Ray

[ME100FINN]

Yeah, the depth of field is something to get used to on the 20d camera (I was :eek: when I saw f22 LOL!!). i can see where the focal point is--that's not so much the issue. Maybe since the images tend to be soft, i dont know HOW much I should sharpen them to get a clean, crisp image in the larger format. Do I view at 100% and if so, what should I see??

See if these screen shots give an indication of what I am talking about. The 21% view looks focused and clean -- it is a jpg Large straight out of the camera.

This is viewed 21% - would a 13x19 look crisp like this? (a little touching up needs to be done first, with a bit of sharpen, remove some noise from ISO1600)
http://img451.imageshack.us/img451/4074/view257lc.jpg

Or would a 13x19 show up more like this 100% view????
http://img109.imageshack.us/img109/2900/view1006bp.jpg

[Carbone]

My own guess (I'm not a pro) is that it won't be so much visible, unless you really stand at 30cm (12 inches) from the picture.

Ray

[ME100FINN]

I may have to suck it up and just print samples...live and learn from experience. I was just hoping to find specifics to narrow down my error margin!! :p

[Carbone]

I'd definitively try a touch of unsharp mask, that's for sure.

Ray

[ME100FINN]

Just as a quick note on the images I posted above--they are not very sharp due to the lens i was using. Did some reseach online and discovered that. Bummer. But I am still wondering how I can determine if the onscreen view is adequate for "x" size print. I tried a couple other shots from the same setting and they will not pass 5x6 size. So that is my only point of reference so far.

[Carbone]

Beatrice,

Are you sure it's the lens? The tone of the picture and the fact that we see the movement is blurry would suggest the picture was taken no flash, at a low lit room, possibly with a very low exposure (under 1/50).

Ray

[ME100FINN]

Yeah Ray--this shot was iso1600 and 1/100 at f5.0 and 300mm. I read lots of reviews,etc on the 70-300 lens (w/o IS). I looked at my shots from my son's basketball earlier that day and it was the sme--all very very soft. This lens is most definitely an outdoor lens...it needs the light to capture a clean shot.

Here's one site
http://www.fredmiranda.com/reviews/showproduct.php?product=18&sort=7&cat=27&page=1

B