Yes, they were different. Here is a quick history:

The Nikon F5 was in incredibly high demand pre-release. The F4 was severely outdated and Canon were taking the pro market away from Nikon with their new EOS line. Nikon tried to combat this market loss by releasing the gap filling F90x/n to hold on to the pro market till the F5 was ready for release.

Due to the high F5 pre-release demand, unlike other cameras, the F5 wasn't immediately available to all photographers amateur and professional. It was first released to professional photographers only. Professional photographers around the world had to put in orders for the F5. Nikon first filled these orders before releasing the F5 to the general public.

These early F5's that went out to pros had the 300XXXX serials. These cameras were the first Nikon F5's. Due to the need for a proper professional Nikon camera at the time, these F5's were all almost certainly put to immediate professional use. They were not purchased to sit around and be lightly used. The very first F5's would've been used, abused, worn out or resold at a later time. To find one of the very first/original F5's today in good condition, I imagine they simply do not exist.

Nikon also released the Nikon F5 as a special collectors 50th anniversary model. The 50th fetches high prices. However, there are likely still many of these sitting completely new and untouched in their boxes by collectors. The F5 that is today likely to be around in the smallest numbers, the most unique, and the rarest of them all is the F5 with 300XXXX serial.

These were the cameras that created the Nikon F5 legend.

Worth checking your serials.

Paul is very accomplished with film and digital devices, and is quite capable of writing about and using either. He has over 22,500 posts on UHH. Many of them seem to be humorous tongue-in-cheek quips, but many contain valuable insights or great images.

A communications medium is not more important than the message it carries, so long as the message reaches its destination in an understandable form.

I used film capture from 1965 to 2005, and have used digital capture ever since. I have no preference for the look of either. In both cases, I know what to do to get the look I want. I DO prefer the digital *process*.

Since I shoot with Nikons, I downloaded the new Nikon Studio program. The layout is a bit of a challenge, but not all that hard. I discovered you can set it up to use Photoshop (or Lightroom Classic) as an external editor. I had played around with a few photos, but after setting up Photoshop in NS, it gave me a chance to see something I'd missed. Nikon Studio seems to display my photos better, and more like I saw the image when I took the photo than either Photoshop or Lightroom Classic. The pics were brighter, and not as "dark" (don't know how to describe that any other way. Maybe it's because NS picks up the Active D-Lighting settings? I noticed this by starting in NS then moved the photo to Photoshop to do some additional tweaking. When the photo opened in Photoshop, it was noticeably darker or "muddy". Now, it's not bad, and the change is really only slight, but it's a different display of the photo. Anybody else notice this? I'm using Photoshop CC.