Canvas size question in PS.

[alicia_fedele]

I am newer to Photoshop- and I have been using Elements, just to

learn. I am SO confused on the sizing aspects etc. I am hoping

someone might be able to spoon feed me.

 

I have a Canon 10D, and when you upload images, they are HUGE!

Then you try to put them on this canvas, and I try to work with 8.5

inches by 11. (just because visually it makes sense to me.. and I can

understand it.)

 

My problem is, If I were to make a coffee table book, what size

canvas do I want to be working with, and what size should my images

be.

 

Also, I feel when I look at the HUGE image in PS, its in focus, but

when I make it smaller to look it -- it becomes blurry. Is this

normal?? I don't understand why its blurry when I make it smaller,

but in total focus when its HUGE.

 

Thanks in advance for your help.

Alicia

[marshall]

When you make it smaller, are you changing the image size, or are you just changing the size that you are viewing it (zooming out, essentially)? If you just zoom out, especially if you zoom out to an uneven multiple (say, 16.7% instead of 25% or 50%), it is averaging values across pixels and that makes it look less sharp. If you re-size the image down, it also averages some values, which is why images typically require some sharpening (USM) after resizing.

 

Your 10D images are big, yes, but you can work with them at that size to make all of your adjustments and then save a master file. You don't need to place them on any other canvas to start with. Just open the file and make adjustments as you desire. The image's Canvas Size will be the same as the Image Size to start with (there are different parameters, but it's a usefully simple way to think of it).

 

From your master file, you'd resize to suit your intended purpose. For instance, if you were prepping images to go into a 10" wide "coffee table book", you might resize them to 8" across (leaving a couple inch margin, or whatever your layout requires) and perform final adjustments there (sharpening for print, soft proofing, etc.).

 

Hope that helps. It sounds like you might benefit from reading some of the online tutorials and/or checking out some of the PS books out there (Martin Evening's comes highly recommended (I haven't read it); Real World Photoshop, by Fraser and Blatner, is excellent but a little technical for some folks).

 

Good luck.

[asimh]

might try this...

<a href="http://luminous-landscape.com/tutorials/understanding-series/und_resolution.shtml">Luminous landscapes TUTORIAL</a>

[alicia_fedele]

Thanks!

I have been reading the Photoshops Element Book.... (I got it at the Library) and its been SO helpful there are just those nagging questions I can't seem to find answers to.

 

Eureka! The zooming out is why its out of focus... Thank you. That makes a great deal of sense. I am thankful that all my pictures are in focus, and its the zooming out... thats making the a tad fuzzy.

 

You guys rock

[fotografz]

When you resize an image make it a % number like 50% or 70%. In-between numbers like

53% or 72% introduce jagged lines and makes it look out of focus or not clear. Try it, you'll

see what I mean.

[alicia_fedele]

Can someone explain to me, the sizes of the images?

I am so confused what I am looking at. I have read this book, but I just don't get it.

 

Basically, I have images that I open "fresh"

It says in the corner 25% 17.067 inches x 11.378 inches

 

Now if I were to view the image in 100%, it makes the image unseeable on my screen.

 

I am trying to figure out, ..

Do I change the inches size? When I change the resolution the sie of the image changes, but I am afraid what will happen when I want to give these images to Joe smo... Will they be able to print them as 8 x11 ???

[bruce_rubenstein___nyc]

After you open the file from the camera go to:

 

Image / Images Size, then set the Height to 8 inches (assuming a horizontal picture). The Width and Resolution will automatically rescale to the new height so long as Resample image is not checked.

 

You may have to crop the width to get it to 11 inches.

[william_au]

Hi Alicia,

 

I'm not a computer/PS expert, but here's my basic understanding from the ground-up. I think of the pixels in my DSLR as individual dots made by a pencil/pen. You could try and draw a picture of a flower using only 10 dots, but it sure wouldn't look like much of a flower. On the other hand, if you used 6,000,000 dots to draw the flower, you could draw a flower that looked pretty life-like. So more dots generally equals better picture.

 

Similarly, your camera can "use" only a "few" pixels to record a picture (e.g. 1536 x 1024 pixels = 1,572,864 pixels = 1.6 Megapixels) or it could use a lot of pixels to record a picture (e.g. 3000 x 2000 pixels = 6 Megapixels). That's the difference you get when you select jpg small vs jpg large on my camera. The jpg large gives you "more dots".

 

Number of pixels is only one part of what determines what the image looks like though. You could spread all 6 million dots over a piece of paper that is as big as Texas and it sure won't look like a flower - unless your dots are as big as elephants and you're viewing from outer space, but let's stick with viewing normal pictures at normal distances. The image therefore also depends on how many of those dots you cram into an inch. The rule of thumb is you need 300 dpi to get photo quality images on paper (the human eye supposedly can't discern beyond 300 dpi, and in reality, many people probably wouldn't notice a big difference at 200 dpi).

 

Going back to my camera, if I need 300 dpi to make a decent image, the largest picture that could be printed with photo quality from my small jpg file of 1024 x 1536 pixels is roughly 3x5 inches (1024 dots divided by 300 dpi = roughly 3 inches, 1536 dots divided by 300 dpi = roughly 5 inches). The larger jpg file of 2000 x 3000 pixels won't necessarily give me a better looking 3x5 photo. My eye wouldn't be able to discern all those extra pixels being crammed into the 3x5 space. What the larger jpg file allows me to do, however, is print a bigger image that is photo quality (roughly 7 inches by 10 inches at 300 dpi).

 

Moving right along to how computers show images: Monitors don't care about dpi. When you set your MONITOR resolution in the Windows Control Panel (if you use PC), you are basically telling it how many pixels the computer should show on the monitor's face. When I set the resolution on my 17 inch monitor to be 1024 x 768 pixels, the computer will simply stretch 1024 x 768 pixels across the 17 inches (12.5 inches x 9.5 inches actually). If I load an image that is exactly 1024 x 768 pixels big onto my computer, it would fill the screen exactly.

 

So it doesn't matter if I tell Photoshop that I want to print my 1024 x 768 file at 3 dpi, 300 dpi, or 3 billion dpi. The monitor just goes, "Hey, all I was told to do was to display 1024 pixels this way, and 768 pixels that way. How you cram these pixels into inches on paper is none of my business." An image with larger pixel dimensions (made up of more dots), like a large jpeg of 3000 x 2000 pixels, has more pixels than can fit on my monitor at a resolution of 1024 x 768. I could fix this by changing my MONITOR resolution to 3000 x 2000 (if my video card and monitor could handle it), but PS makes life easier by showing the image at a reduced magnification so that it fits on my screen. The 25% in the corner means that PS, for viewing purposes, has shrunk the image to 25% of its actual pixel count so that I can see all of it on my monitor. Zooming in simply puts the pixels beyond this "1024 x 768 pixel window" outside of the viewable area of my monitor.

 

So changing PRINT resolution (dpi) of your image has no effect on how it appears on your monitor, but it has an effect on how big your image will be when you print it, and how good your image will look. If your 3000 x 2000 pixel flower image is spread out 1 dot per inch, your PS will try and print an image that is 3000 x 2000 inches large - good luck and guess what - 1 dot per inch isn't going to look like much of a flower. If you squeeze your image into 300 dots per inch, PS will calculate your image size to be roughly 10x6.7 inches (that's the other numbers appearing in the corner). The result would be a 10x6.7 inch print that looked pretty good.

 

Actually, I don't really get 1024 x 768 pixels of viewing area in PS. Some of the screen space is eaten up by the Windows task bar, and some is eaten up by the PS tool palettes. The CANVAS SIZE is the amount of pixels that PS has allotted to view your image. Changing this simply changes how many pixels of your image you can see at one time. When you're actually looking to change the print size or resolution of your photo, you do that through IMAGE SIZE.

 

Now let's say you're taking images at the largest file size (2000 x 3000 pixels) and you want to make a coffee table book with 8x10 images. Your 2000 x 3000 pixel image won't fit on your screen because your monitor has a lower set resolution than that, but that's okay, because you can simply view a lower magnification of your image in PS by zooming out. The important thing here is you need an image of at least 200 dpi that is 8x10 inches in dimension. So that requires an image that is at least 1600 x 2000 pixels large. Perfect! Your file from your camera is bigger than that. In fact, setting your resolution at 200 dpi and leaving the pixel count at 2000 x 3000 pixels would produce a print that was 10x15 inches. So in PS, you would go to Image>Image Size and set your resolution at 200 dpi, and your pixel counts at 1600 width and 2000 height (or vice versa). Bang, that gives you an 8x10 inch image that is 200 dpi.

 

If you're worried 200 dpi isn't going to look good enough, you could always increase the resolution in PS. A 2000 x 3000 file is big enough for you to set the resolution at 240 dpi and still get an 8 x 10 inch photo quality print. You can go higher than this (to 300 dpi, anything more is wasted) and PS will "fake" the higher resolution for you through "upsampling". This works fine if you're only upsampling a bit, but trying to upsample an original 768 x 1024 file to 2400 x 3000 pixel file so that you can print it at 8x10 @ 300 dpi might look pretty computer-generated.

 

Anyways, I hope this is clear and somewhat useful - it was useful for me to think through at any rate. PS/computer gurus out there can feel free to clarify/correct any booboos I made.

[alicia_fedele]

Thanks-- thats basically the visual I needed...

I read the www.photo.net/learn link, and I basically understand the why.... and this post helps me more...

 

I think I just need to know if its OK for me to save images that are 1.8MB and change the 1200x1100 (or whatever) to 500x300 (roughly) and then up the pixels to 200 instead of the 180 they are at, and then when you save it the size of the image changes to 180KB. (Making the file size smaller). Thankfully I backed everything up- so if I really screwed this up--- I'll be Ok.

 

Am I really screwing these up--- or is this ok??

[william_au]

Question: I'm not clear on what you are trying to do when you reduce the pixel count of your image from 1200x1100 to 500x300. If both images were at 200dpi, the 1200x1100 would let you print a quality image up to 6x5.5 inches, while the 500x300 would only let you print a quality image up to 2.5x1.5 inches. If you're purposely trying to make a small image, then this would work fine, but I don't think this is what you're trying to do...?

[Ed_Ingold]

It's the number of pixels that counts, not the nominal size. Some cameras output a file at 72 ppi with large dimensions to fit the number of pixels. This is just a tag for display, which can be changed.

 

If you want to see the entire image on the screen without making any modifications to the image file, simply press ctl-0 (zero) and the image will be zoomed in or out to fit the display. You can crop (change the proportions) if you wish, but it is not necessary. Cropping is a separate operation.

 

In Photoshop, use Image/Size to review and edit the size parameters (without cropping). Check the box "keep proportional" which will allow you to enter values for either length or width, and the other will change proportionally. If you check the box "resample", the new size will have the resolution specified in that box. Unchecked, the resolution will float with the dimensions to keep the same number of pixels.