# resolution



## Morelos (Dec 10, 2004)

whats the minimum resolution/mega-pixels I need to have 8x10 digital prints? and 5x7 ?


yeah, so... thanks in advance


----------



## mrsid99 (Dec 11, 2004)

I've made a decent 8x10 from a 2Mp camera with a JPEG file size around 500K to 600k but that's about the limit and it depends on the pic and subject matter.


----------



## ksmattfish (Dec 11, 2004)

It's purely opinion.  Many folks would say 300ppi.  That isn't anywhere good enough for me.


----------



## rangefinder (Dec 11, 2004)

I used to use a Nikon D1 (3MP) and we routinely printed 8x10 from them.  You need to get good exposure and the best cropping you can - in the camera.

Then crop at 300 dpi.  There's not much value gained in going beyond 300 dpi.  The reason for that being the human eye can only see around 300 not more than that.  Most printers are therefore made to print at 300 dpi and normally discard any file info in excess of that.

The one common exception to this is the Fuji Pictograpghy series which prints at 400 dpi.


----------



## Digital Matt (Dec 11, 2004)

A 2.1mp camera (1600x2100 pixels) can be stretched to an 8x10, but I wouldn't go higher than that.

An 8x10 is 2400x3000 pixels at 300 DPI.

I've done it with "good" results on my old 2.1mp cam, but you can see the distortion if you are looking closely.


----------



## Morelos (Dec 11, 2004)

now I'm confused, what is DPI ?
damn... is there a thread about that somewhere?


----------



## rangefinder (Dec 11, 2004)

You're not alone there.  A lot of people still struggle with the two concepts of pixels and dots.  I can't explain it - I just "understand" it.  Or rather accept it.

Printers use dots, hence dots per inch (dpi).  Electronic images use pixels per inch (ppi).  If I remember correctly 2ppi=1dpi.

So now that we have you seriously confused do a mental erase and remember if you are going to print a hard copy then you'll want your final image to be length X width @300dpi.  

So you download the camera.  Open your imaging software (PhotoShop).  Select the crop tool, specify the size (8inches x 10 inches for example), specify the dpi at 300 and make your crop.  Do you image management (color correction, brightness/contrast, etc.) and save the image.  Now you're ready to print.


----------



## Morelos (Dec 11, 2004)

ah, now I see, thanks a lot, rangefinder! :cheers:


----------



## Morelos (Dec 11, 2004)

ah... now something is bad... photoshop asks me the resolution in PPI, not DPI... so, if you said 2ppi = 1 dpi, am I supposed to set it to... 600dpi? ???

The image size is now 82.4 M !!! is that 82.4 MB?! wtf?!


----------



## Morelos (Dec 11, 2004)

ok, now I'm seriously confused, haha


----------



## rangefinder (Dec 11, 2004)

Just poke in the 300 for the cropping tool.

This is confusing but...just poke in 300 and you'll be fine.


----------



## Patrick (Dec 11, 2004)

What the????
Now I'm confused :shock:


----------



## Morelos (Dec 11, 2004)

now I kind of understand rangefinder... but cant I just download some... lets say 3MP photos from my camera, edit them in photoshop (brightness, colors, etc, NOT the size), save them, take them to the shop and tell the guy to make 'em 8x10 prints? is it necesary to resize them ?

damn, I'm kind of starting with digital printing...


----------



## Digital Matt (Dec 11, 2004)

The confusion gets deeper.  Printers use DPI and LPI.

DPI is the resolution of the printer, and LPI (lines per inch) refers to the way printers reproduce images, simulating continuous tone images by printing lines of halftone spots. The number of lines per inch is the LPI, sometimes also called line frequency. You can think of LPI as the halftone resolution.

The Abreviation DPI gets used generically for resolution though.  PPI is actually LPI x 1.5, but since most of us are lazy and don't want to do that math, we just do LPI x 2 and be done with it.  Most photo labs print at 150 LPI, which would be 225 PPI (DPI, or whatever you want to call it ), but 300 has become lazy standard.

Ok, in answer to your last question, you should resize them yourself, to ensure that they look just how you want.  If your images are not of the 8x10 aspect ratio, they will either stretch or squish to fit, or the printer will crop them, neither of which is desireable.  If you have to crop, at least do it before you print so that you can control it.

Or you can do what I do which is not crop and just print 8x12s and buy custom frames


----------



## Morelos (Dec 11, 2004)

so the correct proportion is 8x12 ??

I tried adjusting the size at Image -> Image size... 

but it actually stretches a little... am I using the wrong function ?

and Digital Matt... I see your point... but how many megapixels are the photos you print 8x12 ?


----------



## Digital Matt (Dec 11, 2004)

Morelos, if you want to print an 8x10, the dimensions are 8x10.  That is 2400x3000 @ 300 PPI.

I have a 6.3 mp camera.  For me 8x10s, or 8x12s are no problem.  Like I said earlier, I printed 8x10s from a 2.1 mp digital camera also.  There is an acceptable limit to which you can stretch your photos.  You can preview this by viewing your pictures at print size in photoshop.  Print size is actually about 38%, so reset your view to that.  If the picture looks good, then it will print good.  If you see too much distortion, then you shouldn't go so big.

You should check the box that says "Constrain Proportions" to prevent from chagning the aspect ratio of your image.  If you want an 8x10 and you change one dimension to 8 and the other is 12, you will have to crop off 2 inches.  I like to open a new document that is 8x10 and paste in my 8x12 and just move it around until I like the composition.  To me, that's the most like taking the picture in the first place.


----------



## Morelos (Dec 12, 2004)

ah, now everything is clear. (or at least clear enough for me to make good prints)

thanks to everyone


----------



## Morelos (Dec 12, 2004)

ok ok, this is the LAST question, I promise, haha...

when I'm changing the image size... the default resolution is 72 ppi... I've been changing it to 300ppi ...

I took an image and left the resolution at 72 ppi and viewed the "print size" and it looks exactly the same as if chosen the 300ppi resolution...  

can someone tell me something about that?


----------



## Digital Matt (Dec 12, 2004)

I don't know Morelos.  There is a big difference in print size between 72 PPI and 300 PPI.  Were the pixel dimensions the same on both images when you compared?


----------



## Morelos (Dec 12, 2004)

no, not the same... much larger on the first one (300) but the print size looked exactly the same


----------



## DocFrankenstein (Dec 12, 2004)

Depends on what cam you're using. If you have a small sensor, you'll need at least 5 mp minimum.

If you have a large sensor, I think 3 mp would be a bit stretching it.

If you have a large 3 layer sensor with 3 layers instead of bayer pattern (sp?), 3 MP should be more than enough.

the more the better. DUH


----------



## Digital Matt (Dec 12, 2004)

5mp for an 8x10?  I've printed 8x10s from a 2.1mp that turned out great.  It was an Olympus point and shoot, and I'm sure it didn't have a big sensor.

Morelos, I don't know what happened, but view them at 38%.  They should be different sizes.


----------



## DocFrankenstein (Dec 12, 2004)

You have a very elastic definition of great


----------



## Digital Matt (Dec 13, 2004)

DocFrankenstein, the quality of the 8x10s I printed from 2.1mp were on par with prints I've seen enlarged from 35mm film.  An 8x10 is not meant to be viewed with a magnifying glass.  Film prints will look bad under that scrutiny as well.

If I could get, and I'll soften my words, "acceptable" 8x10s from a 2.1, then certainly a 3.2mp is plenty high enough quality.  I wouldn't say 5mp is the minimum.


----------



## DocFrankenstein (Dec 13, 2004)

I'm not trying to argue, but you basically equated 35mm film prints and 2.1 mp jpeg...  :shock:  :shock:  :shock: 

Free county. You can beleive in anything... even megapixels.   

don't know what prints you've seen, but no 2 mp camera could match a 35/ISO 100 negative printed on a decent enlarger at 8*10  :?


----------



## Digital Matt (Dec 13, 2004)

It all depends on the photo, the noise/grain.  A nice clean image from a good sensor at 2.1 mp can be interpolated up to 8x10 through photoshop and, barring no noise or artifacts in the original, look as good as an 8x10 from 35mm film, in my opinion.  Have you ever printed an 8x10 from a 2.1mp camera?  I'm not talking about printing it on a lexmark printer at home either.  I'm talking about sending it out and have it printed on high end printer at a lab, at 300 dpi.  The results are quite amazing.


----------



## DocFrankenstein (Dec 13, 2004)

Digital Matt said:
			
		

> It all depends on the photo, the noise/grain.  A nice clean image from a good sensor at 2.1 mp can be interpolated up to 8x10 through photoshop and, barring no noise or artifacts in the original, look as good as an 8x10 from 35mm film, *in my opinion.*


Well, you see... there are currently no 2 mp cameras with good sensors which can produce noiseless images. Sure, if you take sigma SD10 with it's large 3 layer sensor, then sure. 8*10 will look fine with it.

But when you have a 1700-1300 image, with grain, jpeg artifacts and NOISE from the small sensor, there isn't enough detail there to print at that size. 170 pixels per inch from a PS gives really soft results.



> Have you ever printed an 8x10 from a 2.1mp camera?  I'm not talking about printing it on a lexmark printer at home either.


No, I didn't print 2.1 mp. I went from 1.1 HP to 3.2 kodak digicams...

Just for the sake of it, I tried printing the 1.1 mp image...

Cleaned the noise up with ninja
Upsized it too 3000*2400
Printed at 5*4

It's a pic, but it's soft. I don't know what vision you have, but I can see lack of detail from about a meter :?

I also printed another one without the noise removal. A bit sharper bit now I can see the jpeg artifacts from a meter distance.



> I'm talking about sending it out and have it printed on high end printer at a lab, at 300 dpi.  The results are quite amazing.


I have i9900. It's not the lab, but quite close. 


I don't know how you view your 8*10. I expect people to be 30 to maybe 70 cm apart from the print.


----------



## Digital Matt (Dec 13, 2004)

DocFrankenstein said:
			
		

> Well, you see... there are currently no 2 mp cameras with good sensors which can produce noiseless images. Sure, if you take sigma SD10 with it's large 3 layer sensor, then sure. 8*10 will look fine with it.
> .



Really, none?  That's funny.  My Olympus D510, 2.1mp &lt; $200 produced beautiful noise free images at ISO 100.  I have sold prints from this camera. 

I tend to view an 8x10 from 1-3 feet.  (30-90cm)  At this distance, my 2.1mp 8x10s look very good, with no artifacts or distortion visible.

I'm not familiar with your i9900.  I wonder how your $500 printer compares to a $89,000 Fuji Frontier or a Noritisu.  That's what I print on.


----------



## DocFrankenstein (Dec 13, 2004)

Digital Matt said:
			
		

> Really, none?  That's funny.  My Olympus D510, 2.1mp &lt; $200 produced beautiful noise free images at ISO 100.  I have sold prints from this camera.


Oh god, that's not an argument. 



> I tend to view an 8x10 from 1-3 feet.  (30-90cm)  At this distance, my 2.1mp 8x10s look very good, with no artifacts or distortion visible.


I am nowhere near perfect vision and I still see it from 1 meter away :? What's your vision?



> I'm not familiar with your i9900.  I wonder how your $500 printer compares to a $89,000 Fuji Frontier or a Noritisu.  That's what I print on.


It can't print high volume and it can't process film. In term of print quality... I'd say it's better than the lab. Most of those who used it, say it's at least close.

Come on matt. You shoot digital you should know what 8 ink injets are capable of. Just as colorful as the lab. It's more than enough for sharpness tests... trust me


----------



## Digital Matt (Dec 13, 2004)

Let's just agree to disagree.  You've never seen my prints, so you can't comment on them.  I'm sorry if you think that there's no good point and shoot cameras.  Maybe you've just had a bad experience.


----------



## Morelos (Dec 14, 2004)

I just came back from printing and well.... I got good prints, haha, so... yeah, thanks to all 

:cheers:


----------



## Digital Matt (Dec 14, 2004)

Great, glad to hear it.


----------

