Moose Peterson, in his NIKON SYSTEM HANDBOOK (3rd edition) lists several modifications to the F4 made early in the production run, between serial numbers 2100000 and 2180000. These include:

1. changes to the shutter speed dial -- clearer lettering, a higher unlocking button, and greater tension.

This may have taken place between 2115101 and 2146957.

 2. a change to the switch on the viewfinder that sets metering modes; the protrusion that allows one to turn this switch has been lowered in profile to avoid unintended shift from one metering mode to another.

 This change took place AFTER 2146957.

The original switch has a protrusion to help turn the switch that sticks up above the top of the switch where it can catch things and cause the metering to change unintentionally.

The new switch has a protrusion as well, but it extends "out" rather than up and is much less likely to be moved accidentally. The spring tension on this switch has also been increased. This ALSO took place after 2146957.

 Pictures of the original metering switch can be seen in THE NIKON COMPENDIUM, p. 30.

3. the spring on the release lever for opening the back is stronger.

4. the battery warning responds at a lower voltage.

According to Walter Pietsch, Nikon made additional modifications in the F4 since its introduction in 1988. They are:

1) Some strengthening of the metal body, undetectable to the eye.

2) The original F4s had paint used on the shutter speed numbers that peeled and flaked off. If this hasn't happened to yours, then you've got the later model. This change may be included in Moose's change #1 above.

3) Finder has double security to be removed - you need to press the release button until finder is 3/4 off. Moose describes this change (NIKON HANDBOOK, 4th edition) as use of a "double detente on the finder release lever."

The release button on the older model basically looks the same, but it works differently. On the older model as soon as you press the release button the finder is fully loose and can fall off.

 Lawrence Ang reports that this change had been made by the s/no 2301000 body.

4) There is a small rubber "tooth" that sticks out at the top of the right-hand grip and rests on the user's middle finger. This gives more support and a secure confident feeling for your right hand.

Lawrence Ang (6/5/97) reports that this "tooth" was missing from the original model MB-20 grip as well, and was added later to that grip. (Nikon must has liked this feature; it was added to the design of the 6006 and other models).

5) The pin which detects whether the back is open or not was initially a metal and is now made out of white plastic.

6) The battery switch inside the MB-21 grip is now labeled "Ni-Cd" rather than "KR-AA." #6) The finder now has an extra hole in the hot shoe for the security pin of the SB25 and SB 26 flash units.
This last change seems to be most recent. It appears in F4 bodies with serial numbers after 2500000 (Update: Body upto s/n 2500764 haven got the pin modification), but does not appear in bodies with serial numbers between 2400000 and 2500000.

Thus for F4 serial number 2523898, subtract 2100000 to get 423898. Divide by 5000 and get 84.7796. Round to 85 to get 85 months from September of 1988, or 7 years one month, giving approximately October 1995 as the date of manufacture.

Note: Walter says that this process of calculation does not work for F4 bodies for which the serial number starts with 22
 
   

If you have any Nikon F4 / 4s / 4e camera, please send me the related info...your contribution is very very much appreciated.

ps: The easiest way to identify your F4 body is the has the latest changes is by verifying whether the hotshoe has a pin hole on it. However, please notice also that the viewfinder can be changed.

Update Dec 2000: Nikon F4 with serial number 261xxxxx is still available in Japan. It is believe that serial number 261xxxxx is the last batch Nikon produces, and there should be no serial number 262xxxx. Nikon F4 is selling at around 140000~160000 yen in Japan. I know a someone who bought a F4 with serial number 261111111, what a nice number...