Sports Shooter Question: ƒ/4 Fast Enough for NFL?

Nikon D4, Sigma 120-300mm ƒ/2.8 with 1.4 converters, Shot at 630mm, ISO 51200, ƒ/5.6, 1/2000

I saw this post on Sports Shooter and responded to the question because I think sometimes photographers consider a lens or camera and don’t realize many settings can impact the Sharpness of a photo and acceptable noise for publication.

My Response

With today’s camera capabilities with high ISO, I think using a 300mm ƒ/4 lens for NFL football night or day games should not be a problem.

The question you should always be asking is will the photos of the subject connect with the audience.
I would then even take test shots at different ISO settings and compare the results to how the audience sees those photos.
Here is cropped version of the photo above. Notice one major thing between the two images, display size. Size impacts the noise. Again how will the audience view your work?
If they are primarily a website, you can get away with more than print.
Through the years, I have noticed a few things that impact this discussion on sports.
I have noticed a significant difference in the Sharpness of my photos when I drop below 1/1000.
There are a few factors that impact focus. But, unfortunately, so often, people blame a lens when it could be a few other things.
Factors Impacting Sharpness [which can make something look in or out of focus]
  1. I found separating the shutter from focusing and using the back button to focus, and the shutter release to fire the camera improved focusing.
  2. Adjust the fine tune focus on the camera to match the lens. Each camera is different. I use LensAlign
  3. Many lenses I thought didn’t focus that fast magically were great once I upgraded my cameras to newer models.
  4. My Nikon D4 suddenly got ten sharper images when I upgraded the firmware.
  5. On the Nikon system, we have focus tracking. You can change how fast or slow the computer tells the camera to hunt for change in focus point. Focus tracking can make a difference if something comes between you and the subject ever so briefly [referee]
  6. How many focus points do you use for a sport? Sometimes you need fewer and sometimes more. Controlling your focus points is why the camera manufacturers give you choices so that you can maximize your equipment for each situation.
Here is a quick video showing how calibrating your lens can improve the focus.

//player.vimeo.com/video/2504650
I think you can have a ƒ/1.4 lens that should be tact sharp, but because of all the things I mentioned above will perform poorly.

With today’s cameras’ ability to shoot high ISO, and the autofocus in lower light than before, I think you should be okay with a ƒ/4 lens shooting.
In an earlier post, here are some of my photos from an HS Football game shooting at 12,800.
I was curious about pushing the ISO even higher to improve the Sharpness of photos and get even more keepers, so I went to another HS Football game and pushed my ISO to 51200, and here are the results.
The bottom line is always to test something before shooting for the client.