Crop Photos Pixel Calcalutions
thankyou
Is there a trick to this cropping and/or aspect changing thing?
Mostly cropping to fit a desired aspect ratio?
My Canon 350D is 3:2 @ 3465x2304 pixels, that’s a 1.5 ratio, perfect
for at 18x12 or 6x4 print.
Ok, got that, thanks for your help.
But, If I want to print a 5x7 at 1.4 ratio how do I figure out the
number of pixels to crop on one and/or each of the sides of my
3465x2304 pixel, 1.5 ratio?
Or if I want to print a 10x8 at 1.25 ratio how do I figure out the
number of pixels to crop on one and/or each of the side?
Can someone help me with the math formula? The variations are endless,
so is there some trick or suggestions?
I'd like to do this in Canon DPP or IrvanView.
Regards, John
thankyou
I have a copy of PS 6 or 7 that is mothballed and/or if there is a
program I should buy that makes this process simple, please, give me a
suggestion.
John Navas
wrote in
<660d3bf6-b3f3-4038...@n8g2000vbb.googlegroups.com>:
Here's a Google Spreadsheet to calculate what you want:
http://spreadsheets.google.com/ccc?key=rDMiC6CxltvMg2HZDaC0NBA
(Save it for yourself before I delete it.)
--
Best regards,
John (Panasonic DMC-FZ28, and several others)
ray
Basically, to change from 'what you have' to 'what you want', you divide
the width by 'what you have' and then multiply by 'what you want'. Here's
an example:
you have 3465x2304 which is 1.5 aspect ratio and you want 1.4 aspect
ratio. 3465/1.5 * 1.4 = 3234. So you want to crop so you have dimensions
of 3234x2304. So you need to remove 3465 - 3234 = 231 pixels from the
width - 231 from one side or 115 from one side and 116 from the other
side.
thankyou
That’s a good formula. Yep, 3234/2304 = 1.4
Question:
Playing around. When when I divide the height 2304 (instead of the
width) by 1.5 and then multiply by 1.4, I get 1.6 aspect ratio.
2304/1.5*1.4 = 2150
3465/2150 = 1.6
Ok, makes sense, we're increasing the difference, but, (This is
stupid, right?) why doesn't it work and could there be a formula to
figure it out that way?
Really good and useful answer BTW. This one will get some use.
Thank you very much.
J
thankyou
I'd much rather know, which program can do this easily? Am I supposed
to grab a corner of the photo in IrvanView and work from there? Can I
do this in Canon DPP?
I'm thinknig the best would be a program where I can fill in a H x W
box with the numbers to adjust the pixels.
John
John Navas
wrote in
<8a34c507-872f-45ad...@q14g2000vbn.googlegroups.com>:
Photoshop Elements (recommended) will do this for you automatically.
J�rgen Exner
>I�ve posted on this subject last week. Enlarge Digital Photos.
>
>Is there a trick to this cropping and/or aspect changing thing?
>
>Mostly cropping to fit a desired aspect ratio?
>
>My Canon 350D is 3:2 @ 3465x2304 pixels, that�s a 1.5 ratio, perfect
>for at 18x12 or 6x4 print.
>
>Ok, got that, thanks for your help.
>
>But, If I want to print a 5x7 at 1.4 ratio how do I figure out the
>number of pixels to crop on one and/or each of the sides of my
>3465x2304 pixel, 1.5 ratio?
>
>Or if I want to print a 10x8 at 1.25 ratio how do I figure out the
>number of pixels to crop on one and/or each of the side?
Doesn't matter. Pick any two numbers as long as one number divided by
the other number is 1.4 resp. 1.25.
jue
thankyou
In Photoshop Elements, will I be able to choose which side of the
photo to crop off to get the aspect ratio I'm looking for?
Just saying, 'cause "automatically" sounds like the crap I'm getting
from the commercial photo shops.
-------
Jurgen, I think I answer my own "take back" question.
To change the aspect ratio from 1.5 to 1.4 you have to decrease the
difference between Lenght/Width. You can do that by reducing the
length or increasng the width. Ray taught us how to decrease the
Length. If we were able to increase the width to 2470, then we'd have
3465/2470 - = 1.4.
But, of course we can't "really" do that.
John Navas
wrote in
<16d8bf00-f7e1-4aed...@o36g2000vbi.googlegroups.com>:
>Thanks John.
>
>In Photoshop Elements, will I be able to choose which side of the
>photo to crop off to get the aspect ratio I'm looking for?
>Just saying, 'cause "automatically" sounds like the crap I'm getting
>from the commercial photo shops.
In Photoshop Elements, click the Crop tool, specify print dimensions,
then use the tool to select the area you want to print, and it will
match the aspect ratio of the print.
Easier to do than to write -- works very well, dead simple. And
Photoshop Elements is superb for other things as well.
Bob Williams
With either PS 6 or 7 it is an absolute piece of cake.
1) Select the Crop Tool.
2) Type into the height and width box, whatever size you want the image
to be e.g., 4"x6", 5x7, 8x10, 11x14, 7.02x10.53......whatever.
The crop tool will yield an image of exactly those dimensions.
As an added bonus, if you type in 300ppi in the resolution box, the
image will not only be cropped to the right height and width but will
contain enough pixels to create an excellent quality print.
Bob Williams
thankyou
In PS 6/7, what happens to the photo (pixels) when one chooses a print
size (i.e. 4x7, 5x7….)
Is there any control over which pixels are lost?
You wrote: "The crop tool will yield an image of exactly those
dimensions."
In the Ray’s example above, we have to “lose” 231 pixels in length for
a 3:2 (1.5) to become a 5x7 (1.4).
As you say, typing in the HxW is super easy, but, having control over
the lost pixels could be important for the photo composition.
John
If Photoshop Elements has control, 100% PS can do it better.
Bob Larter
200ppi will work fine too.
--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------
John Navas
wrote in <7wH_l.2258$hE....@newsfe13.iad>:
>thankyou wrote:
>> I must add....
>>
>> I have a copy of PS 6 or 7 that is mothballed and/or if there is a
>> program I should buy that makes this process simple, please, give me a
>> suggestion.
>
>With either PS 6 or 7 it is an absolute piece of cake.
>1) Select the Crop Tool.
>2) Type into the height and width box, whatever size you want the image
>to be e.g., 4"x6", 5x7, 8x10, 11x14, 7.02x10.53......whatever.
>The crop tool will yield an image of exactly those dimensions.
Yep.
>As an added bonus, if you type in 300ppi in the resolution box, the
>image will not only be cropped to the right height and width but will
>contain enough pixels to create an excellent quality print.
Unless you know what you are doing with a specialized tool like Genuine
Fractals, any necessary up- or down-sampling is best left to the printer
driver.
John Navas
wrote in
<b314e1ad-f10f-4424...@k20g2000vbp.googlegroups.com>:
>Bob, thanks for the above.
>
>In PS 6/7, what happens to the photo (pixels) when one chooses a print
>size (i.e. 4x7, 5x7�.)
>Is there any control over which pixels are lost?
Yes -- you draw the crop over the image whatever way you want.
>If Photoshop Elements has control, 100% PS can do it better.
Not necessarily. PSE is simply the best bits from PS.
thankyou
NOW:
If I could only find 12" X 18" FRAMES that sell for around the same
price as $11.99 for TWO (16" x 20") at Target.
John
thankyou
Still, looking for a "cheap" 12 x 18
ray
If you decrease the maximum dimension, you decrease the aspect ratio. If
you decrease the minimum dimension, you increase the aspect ratio.
ray
As I recall, it's quite easy in GIMP. That's not something I do routinely.
Bob Williams
It will look more professional to boot.
OR
Crop the image to 16x20, send it out for printing and then mount it in
the 16x20 frames...............Voila!......Done.
Bob Williams
John Navas
wrote in
<797dca66-f072-4f92...@h23g2000vbc.googlegroups.com>:
>I wanted to add the LINK to the Target frame:
>
>http://www.target.com/Set-Elite-Poster-Frames-Black/dp/B001IMTU96/sr=1-3/qid=1244990078/ref=sr_1_3/185-9203499-1059249?ie=UTF8&frombrowse=0&rh=k%3Aframes%5F16x20&page=1
>
>Still, looking for a "cheap" 12 x 18
Inexpensive DIY frame kits can do frames in lots of different sizes --
rails are sold in pairs of various lengths that can be easily assembled
with a screwdriver; e.g., <http://www.framekit.com/>
<http://www.pictureframes.com/html/framingkits.html>
Jeremiah DeWitt Weiner
> I'm thinknig the best would be a program where I can fill in a H x W
> box with the numbers to adjust the pixels.
I'm not sure why this has to be so complicated. In Lightroom, you
just go to the crop function, choose "8x10" or whatever, position the
crop box on the original, and that's it. I would be astonished if most
other image-manipulation programs didn't have similar functionality, no
pixel-calculations necessary.
--
Oh to have a lodge in some vast wilderness. Where rumors of oppression
and deceit, of unsuccessful and successful wars may never reach me
anymore.
-- William Cowper, 1731 - 1800
thankyou
I’m thinking. If I crop my 3:2 (1.5) 3465 x 2304 to 20 x 16 (1.25)
2887.5 x 2304 and then enlarge:
300 dpi = 9.62 x 7.68
250 dpi = 11.55 x 9.21
200 dpi = 14.43 x 11.52
150 dpi = 19.25 x 15.36
To get 20 x 16 I have to use 150 dpi, is that too small?
Thanks. John
John Navas
wrote in
<a4822834-3315-4289...@t10g2000vbg.googlegroups.com>:
Not necessarily, if viewed at a reasonable distance, especially if
upsampled with something like Genuine Fractals. (Send me the image and
I'll do it for you.)
John Navas
<spamf...@navasgroup.com> wrote in
<7m6o355evdbh06j9r...@4ax.com>:
>On Fri, 19 Jun 2009 15:46:16 -0700 (PDT), thankyou <zzhe...@gmail.com>
>wrote
>John,
>
>Thanks for your help. Here is the original photo. What are you going to
>do?
1. Contrast correction
2. Sharpen foreground lion with Focus Magic
3. Blur background with Gaussian blur
4. Upsample for 300 PPI printing at 16x24 with Genuine Fractals
>Crop to 1.25,
I didn't crop -- leaving that to you.
>then if I print it out at 20 x 16 it will be sort of
>crisp, despite the small(er) file size?
I think you'll find the JPEG I sent you is quite crisp, even viewed at
100%. I sharpened the foreground less than the quickie so you wouldn't
see sharpening artifacts.
>Also, what you do mean, "upsampled with... Genuine Fractals." You can
>INCREASE the pixels in a photo?
Yes: <http://www.imaging-resource.com/SOFT/GF/GF.HTM>
>I shoot my Canon 350D in RAW, should I be shooting in the highest
>quality .jpg instead? I don't have to convert to print.
Raw is good when you want the best possible quality in a large print.