Get the Goods: Resolution -- All About the Pixels

I wanted to shared this great iStockphoto Tip of the Month with my readers today. I'm always having trouble trying to figure out the correct resolution formula for various photo print sizes. So I was excited to get this information sent to my email:


Required resolution varies depending on use, but in general, for web & online use, you don’t have to worry about the dpi: just look at the number of pixels. For print you'll need a larger-sized file with a higher resolution. Check with your printer, but large presses usually require an image at 300 dpi. If outputting on a large format inkjet printer, the minimum resolution is probably about 100 dpi, but (with diminishing returns), a higher resolution will produce better results. An average home or office inkjet printer can usually produce fine output with 150 dpi, but higher resolutions produce better results. Your best option is to do a few test prints and see where you can perceive the difference.

The two most important measurements you need to be aware of to ensure your image will be big enough for your use are size and resolution. Yes, especially in this case, size matters. Both can be manipulated in Adobe® Photoshop® under Image, then click Image Size.

The magic resolution formula

To find out if your image is large enough for your end use without pixelating the image, divide the number of pixels by the resolution. For example:


This means the printed piece can be a max of 10” before some loss of image quality. If your printer only required 150 dpi, you could print the image as large as 20”.
What size image do I need for web or print?

What size image do I need for web or print?



If you are still confused then read this great article and hopefully it will help.

An Aside: One Man's Stock Trash is Another Man's Stock Treasure

Last week, I couldn't wait to tell everybody that I finally got accepted to iStockphoto.com. I'm not quite as excited to fess up to this next fact, but I think there could be a good lesson learned from it for all of us budding photogs: Shutterstock rejected every photo I submitted to them!

Shutterstock required I submit a batch of 15 images as part of its application process. Of course I used the three that iStockphoto had already accepted and 12 more I culled from my external hard drive where all my photos live. It looks as though they might have accepted the shot of the deer and the clouds reflected on the office building, but they couldn't be approved because they were unable to approve at least 7 out of the first 10 submitted. To add insult to injury, my uploading function was promptly, though temporarily disabled, as I can try uploading again in a month.

I was shocked by the images they turned down, as they have been some of my most popular sellers in other forums. Even the eye contact with this marvelous fox didn't sway them!




What were the reasons you ask? The fox shot was rejected due to:

NOISE--Noise, film grain, over-sharpening, or artifacts at full size.

While this one and others similar to it were axed because of:
COMPOSITION -- Limited commercial value due to framing, cropping, and/or composition.



I posted about this issue on several of the forums I frequented, including Digital Grin and Digital Photography School, and thought you might be interested in hearing other's responses and experiences they've had trying to get into stock photography.

So here's what I plan to do: I will dedicate all of my initial efforts into giving iStock what they want, learning how to deal with noise and artifacting, etc. by studying their guidelines. Once I get a handle on what differentiates stock photography from other types, I will try again to branch out to other agencies, including Web Shots and Shutterstock. I even asked my instructor Efrain Cruz to consider hosting a stock photography class with Illuminate Photography Workshops to get some tips and techniques from the pros about how to be successful at this type of production.

So how do you fix noise or artifacting? And I can't help but to wonder: do all of these stock agencies reject you on your first try just to see how you will respond? Will you try submitting again or will you hang your head in shame and never turn in anything else? I think it could be a good way of separating the folks who really want it from the ones who just dreaming of success. What do you think?

Breaking News: iStockphoto Accepts My Application!

Second time is the charm! I just got an email this morning confirming that iStockphoto has accepted my application to begin uploading and selling my images on their site! Web designers, writers, and publications are always in need of professional quality images to accompany their websites and stories and often turn to sites such as iStockphoto to purchase photos. I have included the accepted images in this blog entry.

"Welcome to iStockphoto.com, the designer's dirty little secret. Congratulations,
the iStockphoto administrators have determined that your files are commercially
and technically ready for iStockphoto.com. Please begin uploading at your
convenience. There is currently a limit of 15 uploads per 168 hour period."



Last October, I submitted three photos during the application process to become an iStock contributing photographer, but only one of the images was accepted. The other two were declined because of compression artifacting, a common noise and color distortion problem with photo submissions. It probably happened then because I used to keep saving and re saving JPEGs, a process that degrades the image quality every time I save.

I learned a new digital work flow a couple of months ago when I took a Photoshop class with Nat Coalson through Illuminate Photography Workshops. Coalson's suggestions are to shoot in RAW and save original edits as TIFF files (saving the last copy as a JPEG to avoid compression.) I really think this work flow change made the difference in my images.



The first rejection was a tough pill to swallow, and it was a definite blow to my confidence. But I think having that in the back of mind and being aware of all the reasons why iStock won't accept nothing less than quality work made me try harder to become a more competent and technically correct photographer.