How To Prepare Your Digital Images for Emailing.

The picture or image file that comes out of your digital camera will be too large to send by email or display on a web page. That is especially true if you used a high or large quality setting to record your picture.

In addition to being too large to send by email, it will take a long time to load in the recipient’s browser or email program. Patience may not be his or her virtue and they may not wait for your photograph to load.

So, you need to make the image’s pixel size smaller.

For example a picture that I took was stored at 3504 x 2336 pixels, that’s 8 megapixels. Your camera may store up to 4, 6, 8, or even more megapixel per image.

That’s a lot bigger than most people’s monitor. Many people have larger monitors these days, but probably not larger than 1280 x 1024. So, using that as a guide and desiring to keep some degree of quality in the final picture, we will reduce our 3502 x 2336 pixel image to 800 x ?.

You’ll see what the ? means shortly. The 800 pixels on the longest side will give the recipient a reasonably good quality picture and it will be large enough to display quite a bit of detail. If you don’t want to allow too much detail, you could use a smaller value.

Well, how do you make the image smaller? You will need some sort of photo image editing software. There are many programs that will accomplish the task, and many are free. I happen to use Photoshop CS and so, I will go over how you make the image email ready in that program.

The first step is to open the file that contains your image into your editing program. Follow the instructions for your image editing program.

In Photoshop you would select File, then Open. Then you would navigate to the directory on your computer that contains the image that you want to email. Once in that directory, left click on the file and select Open in the dialog box. The image will open into Photoshop.

Once the image is open in Photoshop, select Image and then Image Size. In the dialog box that pops up make sure that the “Resample Image” checkbox and the “Constrain Proportions” checkbox are both checked.

Now in the box called “Pixel Dimensions”, change the longest dimension to 800 pixels. In my case the shortest dimension automatically changed to 533. That’s the ?, I referred to above.

Now click on “OK” to accept the changes that you made. Photoshop will resize the image. It will now appear a lot smaller on you screen. If it is too small, you can use the magnify or zoom tool to enlarge it. This only changes what you are viewing not the actual image file.

If you zoom out until the top bar reaches 100%, that is the size that the image now is and how it will appear in the recipients monitor.

At this point. you want to save the file. Select File, Save for Web. At the top on the bar you will see: “Original”, “Optimized”, “2-Up” and “4-Up”. You can view the quality and file size for each of the various options.

Choose the one that gives you the quality and file size that gives you the compromise that you want. The general idea is to select a file size that will not degrade quality too much. Yet you want a small file size so that the image will load reasonably fast in the recipients email or browser.

Look for a file size of approximately 30K. In my case a file size of 33.1K with a load time of 13 seconds at 28.8 Kbps was available. So, I chose that one.

Select, left click, the image that you want to use and click the save button. In the dialog box that pops up, select the directory in which you want to store the new image file.

If you want to save the image into the same directory, make sure that you give the file a different name or you will overwrite your original image. You might not want to do that, if you have future uses for the image. Click the save button.

Also, when you get back to the Photoshop window and try to close the image file, you may get a dialog box that says “Save Changes to …”. Make sure that you click NO, if you do not want to overwrite your original image file.

Your image file is now ready to attach to your email and forward to your recipient.

Does Lens Focal Length Influence Depth Of Field? For some time now I have been reading reports about this and trying to figure out how it should influence my photography.

This has been taught to us in the textbooks and the photo magazines for a long time and it appears that you get more depth of field with a wide angle lens than you do with a telephoto lens.

If you search the Internet for “depth of field”, you will not look long until you come across many articles that say that using a wide angle lens does not increase depth of field.

Tests have been conducted by many, including some of the photography magazines that prove that depth of field is not dependent on the focal length of the lens being used.

This is a very technical issue and technically it is true. You can even conduct similar tests or experiments to verify it for yourself. However, from a practical standpoint what does this mean to me, the photographer?

All of the information that I have seen so far is based on the hypothesis that you keep the image size the same.

The test goes something like this: using a zoom lens, take a photograph of some subject using a telephoto or long focal length setting. Then zoon out to a wide angle or shorter focal length setting. You could also do this with interchangeable fixed focal length lenses, one telephoto lens and one wide angle lens.

Now, enlarge some section of the photograph taken with the wide angle setting so that the image in that section is the same size as the image in the identical section of the photograph taken with the telephoto setting.

Upon examining the resulting photographs, you will find the depth of field is approximately the same in each of the photographs. There is basically no difference. So, you have proven that technically zooming out to a wide angle focal length did not increase your depth of field.

But, let me ask you a question. Why do you zoom out or switch to a wide angle fixed focal length lens in the first place?

Suppose that you are standing out before some great mountain scene that is beautifully lit with sunrise colors. You zoom in to a telephoto setting and take a picture. Then you zoom out and take a photograph using a small focal length setting.

You want and expect to see more depth of field in the second photograph - all the way from the flower in the foreground to the sunlit mountain peeks. And that’s what you appear to get.

Will it cross your mind that if you blow up a section of the second photograph that you will lose all that apparent depth of field? No, the greater depth of field still appears to be in the photograph taken with the wide angle focal length setting.

You zoomed out so that you could get a wider view and a larger depth of field or at least the perception of more depth of field. You also knew that the images would appear smaller.

Same for zooming in, you wanted to make the image appear larger and you also knew that there would be a perception of less depth of field.

From a practical point of view when you change focal lengths seldom, if ever, will you zoom in or out with the idea in mind of keeping objects the same size.

Using different focal lengths, zooming in or out, gives the perception that depth of field changes. What you get with the wide angle lens appears to have more depth of field than what you get with the telephoto lens.
Technically this may not be the case.

But, what is all of your photography about? The main answer is: what appears right to you. So, I say unless you are a stickler for technical correctness stick with the old time proven rule.

• If you want more depth of field, or you want it to appear that way, use a shorter focal length lens or zoom out.
• If you want less depth of field and a larger image of some part of the scene, zoom in to a longer focal length setting.

This will still give me the photographic results that I want. I have taken a beautiful photograph of a mountain scene and my zone of sharpness appears great.

To me this technical revelation does not change the way I take my photographs. What about you?

After all, this is your art that you are creating. Don’t let the pure technical explanation get in the way of you creating what you want to create.

Continue to pretend that a wide angle lens gives you greater depth of field than a telephoto lens. Your results will show it.