Testing for the SWEET SPOT

NorBro

Major Contributor
After learning a little bit about the lens sharpness from a recent discussion here, I went out and tested my Rokinon 1.4 35mm lens.

In general, 1-3 stops down from wide open is the sweetest, right?

In my particular case, I want sharp footage, but do not want to sacrifice DOF. (Disregard any adding sharpness in post...I want to produce the best results inside the camera before any of that).

Used:

1.4
2
half between 2 and 2.8
2.8
half between 2.8 and 4
4

I studied the images very closely and I truthfully could not tell you which ones were sharper. I would call my eye untrained in this particular observation. But in general, do you think you're able to tell the difference in the sharpness a few stops close to each other in most cases or does it depend on the lens or is it that you just can't tell most of the time because the footage looks the same?

I don't have samples yet.

Just wondering...
 
What where you filming? I find very fine detailed things are the best to film to test for sharpness, a flat surface is not going to be the best, get something like carpet / hair... etc
 
search on google a lens test chart, it will have a ton of details on it so you can check out what is the sharpest. Check out my test, it really shows the difference (even on an expensive zeiss 50mm) of sharpness at different apertures.

password: chart
watch it on vimeo if you can so you can full screen it, makes a big difference

Note: with video, sharpness is a lot hard to determine vs photos where it can really be noticed.
 
I actually just watched my own test shots...kind of terrible to determine anything...using those charts or just having one test subject would work much better..
 
sweet test! Could definitely see it there...which stop do you like best?

With wide lenses Ill stop down to 5.6 or 8 no matter what. If Im using a longer lens like a 50 ill do f2-2.8 for shallow dof and then 4-8 otherwise depending on the situation. Never over 11 and never within 1 stop of open unless i have to.
 
Back
Top