In summary, the conversation discusses the advancements in digital imaging and how it has made performance testing more accessible and affordable. The use of LCD displays for testing is explained, highlighting their differences from old CRT displays. The importance of evaluating lens performance is also mentioned, with a focus on how aperture affects sharpness. Though there may be some difficulty in distinguishing between images, overall the advancements in digital imaging have made a significant impact in performance testing.
  • #1
Andy Resnick
Science Advisor
Education Advisor
Insights Author
7,450
3,206
I’ve done plenty of imaging performance testing on a variety of systems, from millimeter wave through UV. Until very recently, such testing required expensive and specialized equipment. Now, with digital imaging (at least in the visible), you can perform the same type of characterization on your camera for free.
All you need is an LCD display.
LCD displays work totally differently from old CRT displays- they are not raster-scanned, for example. So, you can take photos of the display without fear of flicker (which happens if the shutter speed is not a multiple or fraction of 1/30s).
Why evaluate lens performance? There are at least two reasons.
First, lenses do not deliver constant performance over the full range of f-stop. Trained photographers have a saying “always use the lens stopped down at least 1 stop from maximum”. The reasoning behind this bit of lore is that almost all aberrations get worse with a larger aperture (smaller f-stop). Maximum sharpness will be obtained...

Continue reading...
 
Last edited by a moderator:
  • Like
Likes BillTre, Tom.G and Greg Bernhardt
Computer science news on Phys.org
  • #2
Nice job, Andy. Though I admit it is a bit difficult to tell the difference between the pictures to my untrained eye. They look almost identical for the most part.
 
  • #3
Drakkith said:
Nice job, Andy. Though I admit it is a bit difficult to tell the difference between the pictures to my untrained eye. They look almost identical for the most part.

Thanks!

Which images? The 15/3.5 images are clearly different, the others less so.
 

Related to How to Evaluate a Camera Lens for Performance

1. What factors should I consider when evaluating a camera lens?

The most important factors to consider when evaluating a camera lens for performance include aperture, focal length, sharpness, distortion, and chromatic aberration. You should also consider the lens's build quality, weight, and compatibility with your camera.

2. How can I test a lens's sharpness?

One way to test a lens's sharpness is by taking photos of a detailed subject at different apertures and comparing the results. You can also use specialized tools such as lens resolution charts to measure sharpness.

3. What is chromatic aberration and how does it affect lens performance?

Chromatic aberration, also known as color fringing, is a common optical distortion in lenses that can cause color fringes or halos around high-contrast edges. This can decrease image quality and should be considered when evaluating a lens's performance.

4. How does the build quality of a lens affect its performance?

The build quality of a lens can impact its performance in several ways. A well-constructed lens with high-quality materials can lead to sharper images and better overall performance. It can also affect the lens's durability and resistance to dust, moisture, and other elements.

5. Is it necessary to use a lens hood for optimal performance?

A lens hood can help reduce lens flare and improve contrast in photos, so it is generally recommended to use one for optimal performance. However, the specific lens and shooting conditions may affect the necessity of a lens hood.

Similar threads

Replies
14
Views
2K
  • General Discussion
Replies
1
Views
2K
  • Introductory Physics Homework Help
Replies
8
Views
2K
Replies
13
Views
3K
  • Mechanics
Replies
1
Views
12K
Replies
16
Views
4K
  • Introductory Physics Homework Help
Replies
3
Views
2K
  • Astronomy and Astrophysics
Replies
34
Views
13K
Back
Top