Ronnie Chung's Blog

Did a photo shoot yesterday with Debbie and John which resulted in some good images. During the shoot, I was constantly struggling (not an infrequent thing) with composition among other things. The struggle with composition stood out to me for two reasons. It’s one topic that I never had too much trouble with in over a year. The “A Picture A Day” project was largely responsible for that. Second, I’ve never been very good with composition. That needs to change.

To help with that, I will take on a new project. A project that I hope John and Perry will join me in. For the next few weeks, I will implement various elements of composition/design in photos. It’s similar to “A Picture A Day” project which had the goal of training my eye. Keep in mind this is not something I will post everyday. If Perry and John wants to join me in this, I will host their pictures here as well and at the end of the week we will have a “competition” and see who has the best image out of the group. A friendly competition that will bring some fun and energy to our love of better photography skills. So stay tuned my anonymous internet friends.
Till next time…

Updated WordPress to the newest version today. Unfortunately, it overwrote my theme files with the custom code I added. So I’m switching over to a new theme.

Finally finished processing pics from two shoots I did awhile ago. Galleries are now up:

Kelley and Jessica

Shari

Had a great time shooting with model Shari. Equally great time with Kelley and Jessica for their graduation shoot.

Also did a “bridal shoot” yesterday (Saturday) with my friend Janice Jann as the model. Small world, we didn’t even know that she was going to be the model. Here’s some quick snaps I took with my phone:

Janice and John collapsing the reflector.

Heather fixing the cake. Not the most flattering pic of Janice but I promise to make up for that with the pics from the shoot

More shoots to come soon, hopefully. And I will start working on a new article so stay tuned!

I want to try something new for the next couple of shoots. Created a twitter awhile ago and finally going to put it to use, going to start tweeting during the shoots. Follow me at twitter.com/directorronc

Till next time…

UPDATE: Screwed up the names. Put Jessica instead of Heather.

Haven’t been shooting much lately but here’s some pics:

Created a camera obscura in my room.

Was bored so I went outside to take a self portrait. You can see how bored I was from my blank stare :p

Cat being lazy as usual.

Till next time…

Sharpness – it’s something every photographer cares deeply about whether they admit it or not. For some photographers sharpness is inseparable from a “good” picture. A soft photo is, in their minds, a “bad” photo. The problem is, most photographers don’t know what “sharpness” really is or what they really mean when using that word. In photography, sharpness is made up of two distinct concepts – resolution and acutance.

Keeping with tradition, I’ll keep the technical stuff to a minimum which means this will be a brief overview. In optics, resolution/”sharpness” is measured in line pairs per millimeter (lp/mm). What that means is the ability of the human eye or other “sensor” to perceive the number of lines in a space of one millimeter. The best color films can resolve up to ~100 lp/mm. The best lenses in the world can barely resolve up to 100 lp/mm (this might have changed since the last time I looked up the data). However, none of this really matters because the human eye can only resolve up to about 10 lp/mm. And that’s under OPTIMUM conditions and assuming you have perfect eye sight. Under anything other than the best conditions, it’s closer to about 5-7 lp/mm.

That doesn’t mean that having higher resolution isn’t better. To most people, having 5 lp/mm of resolution would be considered to be really sharp. That’s assuming other things (for this discussion it’s acutance) don’t cause a loss of “sharpness” that is visible to the human eye. In the beginning, I said that sharpness is made up of resolution and acutance. What do these terms mean?

Resolution is something most photographers understand. It’s basically the ability to resolve detail in a scene that we’re photographing. Acutance on the other hand can be thought of as the “contrast” between edges. Basically, the brightness of one edge to the brightness of another. Sharpening or applying a high pass filters in photo editing makes the brightness between edges greater. It is these two concepts that together make up what we call sharpness.

In Photoshop, The GIMP, or any other editing program, there is a filter called Unsharp Mask. This filter is used to sharpen a photo. You’re probably thinking why is it called Unsharp Mask. The reason is the process it uses to sharpen the photo by first blurring the image. Unsharp Mask increases acutance. Same goes with the High Pass filter method of sharpening.

No discussion of sharpening will be complete without discussing viewing distance and viewing medium. I’ll tackle the latter first. Viewing an image on a computer screen has different requirements than viewing a print. A classic example that I see all the time is looking a billboard. From a “normal” distance, the photo on the billboard looks sharp and you can see detail in the scene being displayed. Walk up to within a few inches and all you see is big ass dots of ink. This concept, magnification, is why medium format and large format seems sharper in general compared to 35mm format or smaller formats.

Let’s think about this. Viewing a photo at 100% on a computer screen may looks soft but when viewed at it’s output size (a 12MP camera has a 100% size of about 30×20 printed – I could be wrong about this and I’m too lazy to check) it will look perfectly sharp. People who look at their pictures and complain that it’s soft at 100% are basically walking up to a foot of a billboard and complaining that you can’t see the details. /* Before I continue, I actually finished writing the article but reformatted my laptop and forgot to back up this article first. I’m really pissed right now. */ An image that is soft at 100% on a computer screen can still be sharp depending on the output medium. For example, an image that is soft at 100% when viewed on the computer may be “sharp enough” on a small print (say 4×6) or displayed at low resolution on the web. There are photos that I have posted on the blog that were soft viewed at 100% but appear to be sharp on the web displayed at 800×533.

Awhile ago, I did an engagement shoot for my friend’s brother. Some of the pictures were soft when viewed on the computer. I gave these “soft” pictures to them because when printed at 5×7 (which is the size they wanted) looked sharp enough when viewed from a normal distance. If I printed those any bigger, then you’ll see that they were soft. As a side note, the best color photo paper can only resolve up to ~80-85 lp/mm. It’s important for photographers to remember and know what the final output will be. If I was printing a billboard, anything less than tack sharp would be thrown out. Of course, if the final output will be the web I wouldn’t care too much if it looked soft viewed at 100% on the computer. /* I actually had something much better written but I can’t remember what I wrote and I’m pissed so you get to read this crap instead of the beautiful poetry I wrote earlier */

So that’s a brief explanation of sharpness as it pertains to photography. Very brief but I hope it helps. If you’re interested in the topic, there are plenty of educational photography related sites that explain the concepts in great detail. Or if you’re a CPS member, the Canon EF Lens Works III book is a great resource as well. I’m not sure what the reaction to this post will be like. If the feedback is positive, I’ll consider writing similar articles on other topics. So let me know in the comments what you think!

Till next time…
Fun Fact #1: The difference between the “look” of Japanese glass and German glass is due to the way each manufacturer handles micro-contrast and resolution in their lens design. Leica traditionally favor resolution while Canon favors micro-contrast. In optics, you have to sacrifice more of one to get more of the other.

Fun Fact #2: The only “real” German manufacturer of photographic lenses is Leica. Carl Zeiss AG has moved quite a bit of their manufacturing to Japan. So technically speaking, if you’re buying Zeiss lenses you’re buying Japanese glass :p