# Enlarging  low res images



## Esperanza86 (Nov 25, 2015)

creisinger said:


> Derrel said:
> 
> 
> > Botom line: gorgeous wall-hanging sized prints are easily within reach of even a 10 year old Nikon with 5.4 megapixels of "jiggered", faked up-sampling done in-camera...and any 12 to 24 MP d-slr has all the image quality needed to make big prints...as long as the user uses decent lenses, but even more-importantly, uses good,solid technique and "best practices". ...
> ...




Derrel, It seems you know what you are talking about. I need help! Can you explain to me how to get this to print larger than a 5x7 or 8x10- Most of my images will not print larger than that. I try to print through mpix.com. Also- How do I get my photos more detailed. I picked up on another post you were on that I have been cutting out detail by using my 1.8 f stop. I always chose this f- stop because I love the bokeh and the softness of skin. I now know about dropping my f stop a bit. Here are a few portraits I have taken of people.


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## Big Mike (Nov 25, 2015)

I'm obviously not Derrel, but I'll give it a shot.



> Can you explain to me how to get this to print larger than a 5x7 or 8x10- Most of my images will not print larger than that.


You can print as large as you want...photos are printed for bill boards, so an 8x10 shouldn't be an issue for you.  
What you need to figure out, is why the 'will not print larger than that'.   

The most important spec to be aware of, for printing, is the size of the image (in pixels).  For example, a digital image might be 5,616 pixels wide × 3,744 pixels high.  (Canon 5D mkII).  

So if you are having trouble where a lab won't print larger sizes, it's likely because you don't have enough pixels.  Either you're shooting with the camera set for a small image size, or you are resizing the image before sending it to the lab.  

The rule of thumb is that you want 300 pixels per linear inch of print, so a 5x7 would need to be 1500 x 2100.  Usually, you can go as low as 100 pixels per inch before a lab will refuse to print.  

If you want really large prints, it's OK to have less than 300 P.P.I., the lab can 'upsize' the image, plus you have to consider than a large print should be viewed from further away, so it doesn't have have super high resolution.  



> I picked up on another post you were on that I have been cutting out detail by using my 1.8 f stop. I always chose this f- stop because I love the bokeh and the softness of skin. I now know about dropping my f stop a bit.


I'm not sure what you're referring to about 'cutting out detail'.  It could be that shooting at F1.8 gives you a very shallow DOF, and in some cases it can be too shallow, where you end up blurring 'details' that you might want to keep sharp.

Another issue might be the fact that most lenses are not going to give you their best (sharpest) image quality when used 'wide open' (maximum aperture).   Most lenses (especially the cheaper ones) improve their image quality significantly when you 'stop down' a little bit.   So by using F2.5 or F2.8, you will likely get sharper photos.  Of course, this makes your DOF deeper, but that's a choice you have to make.   This is why many photographers like expensive prime lenses....they often start at something like F1.4 or F1.2.  So besides being sharper because they are built/designed better, they also have a 'sweet spot' that starts around F1.8.


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## cauzimme (Nov 25, 2015)

First you need to go in your Camera setting, you'll find 
Tiff, Jpeg and Raw and different size, use the larger one. ideally raw, then when you open camera raw, be sure to have your 300dpi. 





When I was studying photo, I've print 11x17 and 17x22 photos taken with a powershot for an expo about youngs, media and technology, they just have to be well exposed, well captured. 
So, you should be totally able to do so. 


Now, your soft skin is only soft because it's not on focus. 
Yes in some artistic shot it will totally work but for portraits, printable ''professional'' portrait, forget it. DoF is cool, bokeh looks great yeah when it's well executed, you need to try more apperture. See by yourself. 
Believe me, when you'll look at your crazy sharp image, you'll be happy.


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## KmH (Nov 25, 2015)

Some printing basics.

*Image resolution* = pixel dimensions (4500 pixel  x  3000 pixel)
*Print resolution* = pixels per inch (ppi) and image resolution.
*Aspect Ratio* = shape of the print

*Basic print math*:
Pixels / ppi = inches
Ppi x inches = pixels
Pixels / inches = ppi

Canon, Nikon, Pentax, Sony and other DSLRs deliver photos that have a 3:2 aspect ratio which un-cropped would print as an 8x12, not an 8x10 which has a 5:4 aspect ratio. Olympus DSLR camera image sensors have a 4:3 aspect ratio frame as do many bridge and P&S type cameras.
5x7 is a 7:5 aspect ratio.
A square print has equal length sides - a 1:1 aspect ratio.


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## Esperanza86 (Nov 25, 2015)

Big Mike said:


> I'm obviously not Derrel, but I'll give it a shot.
> 
> 
> 
> ...


Thank You very much! I wonder if when I changed the photo from raw to jpeg it changed the file size? Very weird. I am still a newbie to all of this so I know a little  about this but not enough.


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## cauzimme (Nov 25, 2015)

Esperanza86 said:


> Big Mike said:
> 
> 
> > I'm obviously not Derrel, but I'll give it a shot.
> ...




The file size yes,
The size of the image depends if you touch the dpi...
Open your photoshop, select any photo.
Go to image size, be sure to have réchantillonage box checked.
And have fun changing the dpi, you'll see by yourself what it does to the resolution. Best way to learn.


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## KmH (Nov 25, 2015)

Digital photos have pixels per inch (ppi), not dots per inch (dpi).
Dpi and ppi are not the same thing and as such are not interchangeable terms

Note that Photoshop is careful to make the distinction and uses the correct term.


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## dennybeall (Nov 25, 2015)

Wow, got to 7 comments before we got the DPI<>PPI admonishment.... that's got to be a record.


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## cauzimme (Nov 25, 2015)

You're right sorry, it was however the term we used when I was still studying.

DPI still apply if she's looking to print. Especially if she give business to a small graphic and printer shop, he will probably adress her with dpi.


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## KmH (Nov 26, 2015)

Yes, that's a sad commentary regarding the graphics/print shop also using dpi and ppi as interchangeable terms.

It depends on the type of print being made.
DPI is meaningless for chromogenic and off-set press prints.

Inkjet printers print using dots. Lots of dots per pixel.
Note that inkjet printer resolution is generally not equal in both the vertical and horizontal directions.


> *DPI*
> This is the *usual specification for resolution of output devices*, such as desktop printers, film recorders, RIPs (imagesetters), and (again) computer monitors. For computer monitors and film recorders, there is a 1:1 ratio between the ppi of the digital image file and the dpi of the output device. In most other cases, especially with today's typical desktop inkjet or laser printers, there is a vast difference between dpi and ppi. At an inkjet printer's, say, 2880 dpi resolution, many micro dots of ink are used to build one image pixel. Let's do the math: say that we have an image that is being reproduced at 300 ppi on our 2880 x 2800 dpi inkjet. Dividing, we see that 9.6 dots of ink horizontally and vertically (about 92 dots altogether) are needed to "build" one pixel. Even so, you often cannot tell the difference in print quality betweeen a 2880 dpi print and one made at 1440 dpi.


 DPI, PPI or LPI -- what's the difference? | Adobe Community


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