Square and Circle vs. AE and AEL

[DBMILLER]

I've been looking for a Mamiya 6 (not an MF) on eBay lately, and somebody just asked the following question on one of the listings:

"On the shutter speed dial, does it have a square and a circle for the auto exposure and auto exposure lock or does it say AE and AEL?"

What's the significance of that question? I know the difference between a 6 and a 6MF--but were there also different versions of the 6?

Thanks

 

[snowy]

The original Mamiya 6 had circle and square icons on the shutter speed dial to denote auto exposure and exposure lock respectively. This wasn't very popular, so was replaced by AE and AEL written on the dial for the 6MF. Some users had this dial retro-fitted to their 6's, and Mamiya also did this optionally when replacing the dial under repair, so some 6's now have the "improved" dial.