How Many Characters Can There Be in a Mac File Name?

Good question!

So, how many characters can there be in a Mac file name?
The short answer is 255 including file extension.
But! Not all hard drive and media formats or applications can handle so many characters in a file name.

255 characters gives you a lot of file name real estate for some pretty descriptive file names. That’s handy if you’re keeping your files to yourself or within a small team. But if you plan on sharing your files with the outside world - keep the character maximum to 31…since you never know what system or software others may be using to access your files.

The Color Modes: Bitmap

This is the first in a series of posts discussing the color modes in Adobe Photoshop. My previous post, ‘256 Shades of Gray: A Ribald Tale of Bit Depth’ covered the color modes available in Photoshop when starting a new document. This series of postings will go into each one of those modes in a little more depth plus cover the other secondary color modes.

The Bitmap Color Mode in Adobe Photoshop

So when would using the Bitmap color mode be useful, or even necessary, in Photoshop?
What I’ve frequently used the Bitmap mode for is for a persons signature or a one color graphic or logo that needs to be included in a layout. Also when I haven’t had a high res digital file of a one color graphic, but I do have a clear and sharp print which I can scan and bring into Photoshop. And when I say “one color”, I mean one “solid” color, as a Bitmap cannot include multiple percentages.

When creating a Bitmap file you have the option of selecting a custom DPI. For Bitmaps you should not select anything lower than 1200 dpi at 100% print size. So when you place a Bitmap in an Illustrator or InDesign document it should be at 100%. If you need to scale the graphic up or in the layout, you should resize the file in Photoshop so that it resets to 100% in the layout program. You should be able to scale down without any negative effects.

And remember that anything that appears white in the Bitmap Photoshop file will appear and print transparent in the layout program.

Once in the layout program you can apply any color to the Bitmap file. If for any reason you do want to add a gradient or other effect to the Bitmap graphic you can do that in the layout program using an Opacity Mask or Effects Filters in Illustrator and Effects Filters in InDesign.

Bitmap files are pretty simple but pretty handy too...and not too limited if you consider the effects you can apply in Illustrator and InDesign.

    

256 Shades of Gray: A Ribald Tale of Bit Depth

Who knew working with image files could be so titillating? No one knew, because it’s not. But image files can have more than 50 shades of gray. They can have up to 256…and trillions of colors Now that’s exciting!

Before you start working with color, you should start thinking in black & white, or more specifically, grayscale. No matter what color mode or bit depth you choose, keep in mind that you are dealing with one channel for each color. Each of those channels consists of different grays. Keeping that in mind, if you focus on controlling the levels and dynamics of those grays in each channel, your final image will look the best it can for the intended design. More on this later.

This posting focuses on selecting which Color Mode & Bit Depth to choose when creating a file in Adobe Photoshop. 

Following this posting I will have additional postings focusing on the individual color modes in Photoshop.

THE COLOR MODES

When should you choose which mode when starting a new Photoshop document?

When you start a brand-spanking new document in Photoshop you are given the choice of the following Color Modes:

Bitmap: When you are only printing one solid color. It can be black, white or any single ink or spot color.

Grayscale: When you are only printing one solid color, but want tints or screens of that color. The color can be black, white or any single ink or spot color. But check with your print vendor to see how they handle whites. Not all printers are equal when it comes to printing white.

RGB Color: RGB is Red Green Blue, of course. It is the color space that we humans perceive. It is the color of light. Choose RGB if you want access to all of the filters in Photoshop. Definitely choose RGB if you will only be creating art for digital/on-screen viewing. But also choose RGB if you are printing to a large format printer, printing on a digital press, printing to an inkjet printer or printing in the Hexachrome (six-color CMYKOG) format. You may need to convert to CMYK before print and will deal with some color shifts (depending on how far out in the RGB spectrum some of your colors go). If your image has bright reds, blues and greens - use RGB.

CMYK Color: Cyan Magenta Yellow Black are the standard process printing colors. You can look at CMYK as the universal stock color mode. You can pretty much guarantee that any print vendor you select for your print job will have a four color press that is set up to run CMYK. Most print vendors will have 6, 7 or 8 color print presses which will allow you to add spot colors and varnishes…at a cost. If you’re not concerned with a wide range of bright colors - you are safe to choose CMYK from the start.
Lab Color: ‘Lab’ stands for ‘Lightness’, ‘a’, ‘b’ - which refer to the three channels available in the file. (The ‘L’ in Lab is sometimes referred to as ‘Luminosity’.) Lab color describes all of the colors that a person with normal vision perceives. This mode is intended to give you options to get the most out of the contrast and colors in an image. With the Lightness channel you adjust the grays on a 0 to 100 Scale. With the ‘a’ channel you adjust based on a Yellow to Blue scale. With the ‘b’ channel you adjust based on a Magenta to Green scale. The Lab Color Mode gives you the biggest color gamut. The best way to get familiar with the Lab mode is to work with an image which has wide varying contrasts and colors. It’s effects are not needed for all images, but you may be surprised how Lab really makes some images sing. Give it a try. You may be pleased with the results.

BIT DEPTH

Bit Depth Choices in Adobe Photoshop
Along with the color mode choices, when you start a new document in Photoshop, you have some bit counts from which to choose. The bit depth choices per Color Mode are as follows:
Bitmap: 1 bit
Grayscale: 8 bit, 16 bit, 32 bit
RGB Color: 8 bit, 16 bit, 32 bit
CMYK Color: 8 bit, 16 bit
Lab Color: 8 bit, 16 bit

The long and short of it is - The more bit depth, the more colors per byte, the more an image approaches the range of color and contrast the human eye can perceive.

So which Bit Depth do you choose? 
If you are creating a job for print, the short answer is - 8 Bit.
If you are creating a job for screen or web, the answer is - 16 Bit.
If you are creating a job for both print and screen, the answer is - 16 Bit with conversion to 8 Bit before releasing for print.

When, if at all, should you choose 32 Bit? 
The goal with 32 bit (HDR - high dynamic range) images is to come close to or simulate what the human eye sees. The human eye can perceive a much higher range of colors and contrast than a camera can. 32 bit gives you much more colors per digital byte with which to work. Some 32 bit images, on screen, can look almost freakishly unreal. But if you take the time to look around your world, when you are out and about, you will realize that you see many colors and contrasts, but you may choose to ignore them simply because you really don’t need to take all of that in to get through your day. The goal of 32 bit is to try to capture those real world colors and contrasts.

With any of the choices of Color Modes or Bit Depths available in Photoshop you have to consider, not just your design intent, but your source image. Don’t bother using 32 bit if you are generating a custom graphic which you create directly in Photoshop. If your source image has been shot in 32 bit, then try to keep it in 32 bit, or convert to 16 bit, for the editing process. You can then convert a copy to 16 bit or 8 bit after your final edits.

More choices of filters with 8 Bit compared to 16 Bit.
With 8 bit you will have more choices of filters to use on your image and any print vendor will be able to process an 8 bit image. But if your design includes photographic images which need to stand out using dynamic contrast and color, use 16 bit for the retouching and editing process. You can then convert to 8 bit to apply any additional filters and to send out the final file for printing. If you have direct access to the print vendor, ask them if they can handle 16 bit images. You may be able to release as a 16 bit file, if they can handle it.

Do you need to understand the math behind the Bits?
NO!

You can, if you want, but most explanations of bit depth that I’ve read go off on (what seem to me) to be scientific explanations geared towards those who have accomplished their math doctorates. Most of us who work in graphic design and production have no time or brain bandwidth to decipher these explanations. So I won’t try to explain too much of the math behind bits, bytes and binaries. I have a little of the math behind the bits at the end of this posting...for the morbidly curious. 

All you really need to know about bits, as I said above, is:

The more bits, the more colors per byte, the more an image approaches the range of color and contrast the human eye can perceive.

So where do the 256 Shades of Gray come in?

Each channel in a Photoshop file can be comprised of black, white or grays. You then combine or blend those channels (or plates - if your thinking along the lines of printing). Each channel is then assigned a different single color. Such as red, green, blue, cyan, magenta, yellow, black, spot PMS, etc. With Lab you work with grays or color ranges for the ‘a’ and ‘b’ channels. If you’re printing using spot colors you can add additional channels (plates) or swap out the standard RGB or CMYK channels. If you are working with 16 or 32 bit, you have more levels of grays between the white and black. With 1 bit, you just have black and white.

So when you think of color, think of the range or levels of grays that go into each channel. This is what really gives and image it’s dynamics.

THE BINARY SYSTEM, BITS & BYTES

First let’s quickly explain the basics of the binary system. The binary system is all the ‘0’s and ‘1’s you hear about. The ‘0‘ represents ‘black’. The ‘1’ represents ‘white’.

Bits

A ‘bit’ is that 0 or 1.

Bytes

A byte is 8 bits. It can represents 256 colors. That is arrived at by calculating 2 to the 8 power (2x2x2x2x2x2x2x2). That is to say - 1x2=2, 2x2=4, 2x4=8, 2x8=16, 2x16=32, 2x32=64, 2x64=128, 2x128=256. The more bits you have, the more these calculations expand to the higher dynamic range of color perception.

Swatch Names in Illustrator and Their Connection to Photoshop Spot Channels

If you like to keep your swatch names in Illustrator organized (as you should), remember that when you place a Photoshop file that contains spot channels in an Illustrator document, the spot channel colors are added to the Illustrator Swatch panel. And the names appear exactly as they are written in the Photoshop channel.

So if you have a swatch created in Illustrator that is supposed to print the same color as the color in the Photoshop file, it should be written the exact same way. If it’s not, when the Photoshop file is placed in Illustrator, a new swatch will be added in addition to the swatch in Illustrator.

You can quickly fix this conflict by first clicking on the swatch color name in the Swatch panel that comes from the Photoshop file, then hold your Command key (Control key on PC) and click on the similar (but different) name of the swatch created in Illustrator. Then, with both swatches highlighted, select ‘Merge Swatches’ from Swatch panel option menu. This will combine the swatches into one to ensure that they separate to the same printing plate. This will also match the coloring of any vector graphic in the file to that of the spot color in the Photoshop file.

If you try to merge the name of the swatch from the Illustrator file to that of the Photoshop file…it won’t work. The swatch name from the Photoshop file is essentially locked into the Illustrator file. That’s because you can’t make changes to a Photoshop file using Illustrator. Makes sense.

If you prefer the swatch name format from the Illustrator file, just open the Photoshop file and change the name of the spot channel to match that of the Illustrator file. After you’ve saved the file and refreshed the Illustrator document, the swatch will combine with the Illustrator swatch. But the old Photoshop swatch name will probably still exist. You can get rid of it by selecting ‘Select All Unused’ and click on the trash icon in the swatch panel. If that doesn’t work, you should save the document, close it and reopen it. That will free up any unused swatches to be deleted.

CUSTOM SPOT COLORS

If you’ve created a custom spot color in both the Illustrator & Photoshop documents, but they are of different hues/tints, the hue/tint that exists in the Illustrator document will be adapted to the color from the Photoshop file. This is not a bad thing. It will ensure that your colors are common throughout all files associated with the primary Illustrator file. The hue and tint in the Photoshop file will stay the same. It will just appear different in Illustrator to ensure a match color.

If this isn’t to your liking you can adjust the swatch color in Illustrator to match that of the Photoshop file. This is probably the better approach anyway. It keeps things clean and organized.