So JCook,
what you're saying is that whatever it is, 300 dpi, or 72, but large, the file that needs to be zoomed into the same way, will be the same bit size regardless.
So if I scan a pencil at 300 dpi, or scan it at 72, but put the scale % up to get it to the size large enough to zoom in as the 300dpi one would allow, the file size is the same, and Moho will struggle the same way with either?
So to Moho it doesn't really make much difference if it's small at 300 dpi, or huge at 72?
What is the recommended way of doing things then? should one try scanning and boosting whilst scanning, or scan at 100%, at 300 dpi?
uncompressed quicktime export. quality is low
Moderators: Víctor Paredes, Belgarath, slowtiger
I guess basically that's true.
Here are the stats on the images I tested:
Original images -
A. 300 dpi - 2400x1800 pixels, 3.2MB
B. 72dpi (only the resolution changed) - 57x432 pixels, 307kB
Then I resized the images:
C. 300dpi resized to 576x432 pixels, 304.9 kb
D. 72dpi resized to 2400x1800 pixels, 3.2 MB
Images A and B are the same physical size in inches, 8x6. But in pixel size (or you might call it screen size) they are different dimensions. That's because the screen will only show 72 pixels per inch. So, when viewing the 300dpi image, the pixels on the screen are the same size as those in the 72dpi image, and so the image becomes bigger on screen only, not in print. If I zoom in to the 72dpi image B, the quality suffers, but not when I zoom into the image A.
Images C and D are actually resized in pixel dimensions. Image D, is 72 dpi, but has been resized to the same pixel dimensions as Image A (300 dpi) and is the same file size also. And similarly with Image C. It's been sized smaller, and, although it's 300 dpi, zooming in gives bad quality.
I got the exact same quality when I zoomed in on either image A, or D, because of the pixel dimensions being the same. This is a confusing topic, but it's important, and I hope my explanation isn't too confusing.
As far as scanning, I always scan at high resolution and change it in Photoshop if I need a lower resolution, always working from high to low, and not the reverse. I scan at 100%.
Hope this is helpful.
Jack
Here are the stats on the images I tested:
Original images -
A. 300 dpi - 2400x1800 pixels, 3.2MB
B. 72dpi (only the resolution changed) - 57x432 pixels, 307kB
Then I resized the images:
C. 300dpi resized to 576x432 pixels, 304.9 kb
D. 72dpi resized to 2400x1800 pixels, 3.2 MB
Images A and B are the same physical size in inches, 8x6. But in pixel size (or you might call it screen size) they are different dimensions. That's because the screen will only show 72 pixels per inch. So, when viewing the 300dpi image, the pixels on the screen are the same size as those in the 72dpi image, and so the image becomes bigger on screen only, not in print. If I zoom in to the 72dpi image B, the quality suffers, but not when I zoom into the image A.
Images C and D are actually resized in pixel dimensions. Image D, is 72 dpi, but has been resized to the same pixel dimensions as Image A (300 dpi) and is the same file size also. And similarly with Image C. It's been sized smaller, and, although it's 300 dpi, zooming in gives bad quality.
I got the exact same quality when I zoomed in on either image A, or D, because of the pixel dimensions being the same. This is a confusing topic, but it's important, and I hope my explanation isn't too confusing.
As far as scanning, I always scan at high resolution and change it in Photoshop if I need a lower resolution, always working from high to low, and not the reverse. I scan at 100%.
Hope this is helpful.
Jack
i think I'm starting to get my head around it now.
thanks a lot Jack.
but at the same time I'm still confused.
As I am finally understanding, a file scanned at 100% @ 300 dpi is larger file size compared to the same thing scanned at 72 dpi.
The file size does not change however when you bring a 300 dpi scan down to 72 with the "resample Image Bicubic" ticked off.
in this case the zooming in capacity is the same also.
so if the pixel count is the same, does Moho notice a difference between the 300 dpi image and the 72?
I am more comfortable using the 300 one in case anythig needs canging in PS...
or am I still lost?
thanks a lot Jack.
but at the same time I'm still confused.
As I am finally understanding, a file scanned at 100% @ 300 dpi is larger file size compared to the same thing scanned at 72 dpi.
The file size does not change however when you bring a 300 dpi scan down to 72 with the "resample Image Bicubic" ticked off.
in this case the zooming in capacity is the same also.
so if the pixel count is the same, does Moho notice a difference between the 300 dpi image and the 72?
I am more comfortable using the 300 one in case anythig needs canging in PS...
or am I still lost?
Right, because there is more information in the file.As I am finally understanding, a file scanned at 100% @ 300 dpi is larger file size compared to the same thing scanned at 72 dpi.
The best way to understand this is to try some experiments with some files yourself. Scan an image at high resolution, say 300dpi because that's what we've been talking about. Bring it into Photoshop (or whatever image editor you use) and change the resolution to 72dpi. Immediately you'll see the image become smaller on the screen. Look at the Image Size dialog box in Photoshop when you do this and you'll see the dimension size. You'll see at the top "Pixel Dimensions," and it tells you how many pixels are in the picture. Below that is "Document Size," where it shows the physical dimensions of the picture in inches, or whatever unit you have it set to. At the bottom is the resolution. Compare these two boxes at the 300dpi resolution, and then after you've changed it to 72dpi, and you'll see that the "Pixel Dimensions" have decreased, while the "Document Size" has not. It's because there is less information in an inch at 72 dpi than at 300. The key is dpi, which means "dots per inch." There are 72 dots in an inch at 72dpi, but when it's 300 dpi, there are 300 dots in an inch. But the screen can only show 72, so the Pixel Dimension at 300 is bigger than at 72. So is file size, because there's more information at 300.
Jack
Keep in mind also...
"inches" only exist in the "real world". The screen displays 72 dpi. So... if something is 1000 px x 1000 px it doesn't matter if that is 72 dpi or 300 dpi... both of those are exactly the same. You will only see that differnce in programs that use inches... like Quark or Adobe Indesign... or MS Word. Those programs deal with printing in "the real world" space... which is inches.
In photoshop you can change the DPI with out changing the image by turning off "Resample Image". A 72 dpi image changed to 300dpi only changes the relationship of the file in printing. In photoshop it will appear as if nothing happened (nothing did really) but the size in inches change.
If you had an image that was 100 px x 100 px and it was 72 dpi and you printed it... it would print larger on the paper than the exact same file set to 300 dpi... but it would look all pixelated because those 100 pixels are being printed large enough to "see" on the page.
Generally in the print world... proper resolution can be determined by the actuall file "size" in megabytes.... rather than resolution. In the past, print shops would tell me they need a photo to be "25mb" or "100mb" to print at a specific size at a specific LPI (lines per inch for printing) to look good.
Or they would tell me specific pixel widths and heights...
"make sure the photo on page 3 is 2400 pixels x 3600 pixels."
That kind of thing. DPI didn't matter.
p.s. it can be very confusing.
-Vern
"inches" only exist in the "real world". The screen displays 72 dpi. So... if something is 1000 px x 1000 px it doesn't matter if that is 72 dpi or 300 dpi... both of those are exactly the same. You will only see that differnce in programs that use inches... like Quark or Adobe Indesign... or MS Word. Those programs deal with printing in "the real world" space... which is inches.
In photoshop you can change the DPI with out changing the image by turning off "Resample Image". A 72 dpi image changed to 300dpi only changes the relationship of the file in printing. In photoshop it will appear as if nothing happened (nothing did really) but the size in inches change.
If you had an image that was 100 px x 100 px and it was 72 dpi and you printed it... it would print larger on the paper than the exact same file set to 300 dpi... but it would look all pixelated because those 100 pixels are being printed large enough to "see" on the page.
Generally in the print world... proper resolution can be determined by the actuall file "size" in megabytes.... rather than resolution. In the past, print shops would tell me they need a photo to be "25mb" or "100mb" to print at a specific size at a specific LPI (lines per inch for printing) to look good.
Or they would tell me specific pixel widths and heights...
"make sure the photo on page 3 is 2400 pixels x 3600 pixels."
That kind of thing. DPI didn't matter.
p.s. it can be very confusing.
-Vern
Well, at the risk of making it seem even more confusing, I would qualify the above comments: the dpi setting is used - but only when you need to import a bitmap image into Moho. If you are only using vectors, dpi settings don't come into it.
The way I think about it is simply to think of dots as being the same as pixels. So, instead of thinking of a scan resolution as being 72 dots per inch, I think of it as 72 pixels per inch. If the artwork you are scanning in is 10 inches wide and it's scanned in at 72 dpi, then the image in Moho will be 10 x 72 = 720 pixels wide - which is just about OK for PAL TV use, providing you don't zoom in.
Someone may well say that I am being an idiot for saying this, but I can only say that I have done a fair bit of scanning for broadcast and film work and even if my theory is nonsense, it always worked out fine!
Jeff
The way I think about it is simply to think of dots as being the same as pixels. So, instead of thinking of a scan resolution as being 72 dots per inch, I think of it as 72 pixels per inch. If the artwork you are scanning in is 10 inches wide and it's scanned in at 72 dpi, then the image in Moho will be 10 x 72 = 720 pixels wide - which is just about OK for PAL TV use, providing you don't zoom in.
Someone may well say that I am being an idiot for saying this, but I can only say that I have done a fair bit of scanning for broadcast and film work and even if my theory is nonsense, it always worked out fine!
Jeff
Sorry Jeff...the dpi setting is used - but only when you need to import a bitmap image into Moho. If you are only using vectors, dpi settings don't come into it.
This is NOT true. An image that is 300 pixels X 300 pixels at 72 DPI is the exact same size in moho (same size period actually) as an image that is 300 pixels X 300 pixels at 300 DPI.
As has been said. DPI means nothing to these types of programs since they always deal with ONE resolution only... 72 dpi. To moho EVERYTHING is 72 dpi. Only the physical pixel size matters... 300 pixels X 300 pixels.
The only time that DPI effects the image is if you "down size it" when you change the resolution.
The default behaviour in photoshop is too Resample the image... meaning changing from 300 dpi to 72 removes pixels.
You must uncheck that box in the image size window to change dpi without changing the image.
If you want the image smaller you can just change the dpi without unchecking resample image... but in this case it is better to change the pixel dimensions (don't make it bigger... that just looks ugly).
Rilke... you're okay. 72 dpi. Pixel dimensions. That is the only thing to remember. The height and width in pixels is the only thing to worry about size in Moho.
-Vern