# 14-bit maximum frame rate of the D300s (Technical information)

Started Feb 5, 2012 | Discussions thread
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 Re: OK, a last attempt. In reply to olyflyer, Feb 10, 2012

olyflyer wrote:

OK, here it is once again for the last time. I put it a bit differently and hoping youâ€™ll understand how to calculate fps in a more practical use based way.

I took four images in that example.

Total time to take those four images was 1140 ms.
1140/4 = 285 making the average time per image to 285 ms.
1 second is equal 1000 ms.
1000/285 = 3.50877....

In other words, those four images were taken at a frame rate of 3.51 Frames Per Second.

Please correct me if I am wrong.

The time between image 1 and 2 was 410 ms.
The time between image 2 and 3 was 370 ms.
The time between image 3 and 4 was 360 ms.

What you are missing is one image, the starting image. That image is also taken, so what the above shows is not the frame rate but interval between two images. I listed the intermediate results in parenthesis just to show the fps you'd get in that case. As you also can see, the value is varying, in this example even though I took four images without moving the camera, the interval between images 3-4 was the shortest and 1-2 was the longest. I take it as the worst case scenario is 1-2 and a more realistic is at least four images after each other.

Now, if you draw a time line it will look like this:

Image 1 ---------------- Image 2 -------------- Image 3 ----------- Image 4

0 ms ---------------------- 410 ms -------------- 370 ms ------------- 360 ms

Now, using simple addition: 0 + 410 + 370 + 360 = 1140 ms

...and we are back again at 285 ms per image and 3.5 fps for the four images.

Please correct me if I am wrong.

The camera manages to keep considerably higher than 2.5 fps until the buffer is full, at least the first 7 images are much faster, but also up to image 18 it was well above.

This is what's important for anyone using the camera, not just reading specs, because this is the realistic way of calculating it based on use.

The specified 2.5 fps seems to be the lower limit, worst case scenario and it is good to know, but very few people take only two images in continuous shooting mode.

...I still don't understand where you got the 190 ms from but never mind.

Hi,
I think it it should be like that:

Image 1 ---------------- Image 2 -------------- Image 3 ----------- Image 4
410 ms -------------- 370 ms ------------------360 ms

if we are talking about time laps. 410 ms for first image and camera starts to take second image, 370 ms for second image and camera starts to take third, etc. So 1140 ms is a full cycle time for 3 images. 1140:3=380 ms which is 2.63 fps.

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Best regards

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