BR2 vs.BR2A reversing rings

I own a BR-2 lens reversing ring. While getting my F4s serviced at

NIKON in Torrance, CA I asked what the difference was between a BR-2

and a BR-2A ring. I person returned five minutes later and said none of

the technicians knew of a difference between the two(!) I figured they

must not have looked at them side by side so I bought a BR-2A ring from

B&H and when it arrived I compared the two. Nearly identical. I found

two minor differences of no real consequence, and I mean minor! I

emailed NIKON through their website and received a reply that said "the

BR-2A is for auto focus bodies and the BR-2 is for manual focus bodies.

Do not use the older ring on an AF body as damage to the contacts may

result."

The owner's manuals for my F4s and F100 say to use the newer ring.

However, I have been using the BR-2 on my F4s for a while now. It

clears the electrical contacts just fine. When I emailed them back and

notified them of this here's what they said:

 

"We have found that you already visited Nikon in Torrance and the

technicians could not provide information of the differences of the two

rings. Therefore, I do not have the information either. However, we still

advise to use only the BR-2A ring for autofocus cameras as the

instruction manual indicates. The BR-2 is not recommended. The

factory would not have replaced the BR-2 with the BR-2A if there was no

compatibility issue. If we obtain more information on this issue we will

let you know."

 

I know this isn't an earthshaking issue but if someone can answer this

question then maybe NIKON should be notified too.

I do remember that right before the introduction of the BR-2A ring I think that there was one or maybe two lenses or extension rings that had a clearance problem.

 

I may be wrong, but it may have been done to make compatible all lenses when in fact only one or two lenses or extension rings possibly were reported to have a problem with the old one, so they made a change to make sure it would clear for everything.

 

I may be wrong on this, but I remember something to this effect.

I know that they say to use the BR2A instead of the BR2, but I haven't had any problems with the BR2 on my F4S.

Hi, I have a BR-2 reversing ring. It will not mount on my F-601. The ring jams up against the CPU contacts in the camera, it won't fit. If your BR-2 fits your F4, I can only guess the F4 has a little more clearance inside, although that seems strange since all Nikon AF cameras should have CPU contacts in the same place.

 

The BR-2A has a little extra milled away from the mount so it clears the CPU contacts. Otherwise it is almost identical to the BR-2.

The BR-2 clears the contacts on my F4s and my F100 by such a large amount that I didn't think the tiny amount of extra milling would matter.

 

You are correct, there is indeed a little bit more milled off between the bayonet (?) lugs that attach the unit to the lens mount.

 

My hat's off to you. NIKON tech dept. in Torrance, CA couldn't answer that one. Neither could the NIKON website. Maybe we should direct them to this forum?

Thanks,

Joe

<p>This seems very confusing about the BR-2 and BR-2A. If the BR-2 used the same design as all the old manual focus lenses, the old extension tubes, the old bellows, etc., then why is there not a similar requirement for attaching those devices to DSLRs? I now have both the BR-2 and BR-2A in front of me and have attempted to find the differences by using various micrometers, and I have not figured out the difference. Could this be related to use with the less than professional Nikon cameras only? I'm going to spend some more time measuring the BR-2 and BR-2A, but it must be extremely subtle. As I said, my question is why do the old MF lenses still work then? </p>

<p>The one thing that I overlooked was that there are three U-shaped milling areas on the back face. The BR-2A's are just a tad larger. I don't have an appropriate means to measure the difference.</p>