Without looking at the Bellows manual I would opine that it would be
surprising to find that Olympus did not use the 49/55mm thread there, as it
is intended for reversing OM lenses on the (reversed) front standard. Why
would they use a thread incompatible with all and any of their own lenses?
And in place of reading a secondary source (useful as the eSIF is), why not
try it?
So I did look at the 12/81 edition of the Auto Bellows manual, and guess
what?
I was wrong.
And so is the eSIF, only more wronger (!)
It's a 49mm thread, as "The adapter ring 55-49mm is needed to reverse the
Macro 55mm F1.2 on the bellows" (p 14). Granted, they described the 55/1.2
as a Macro lens, which it isn't, but it does have a 55mm filter thread, from
which I conclude the bellows has only a 49mm thread.
Piers
-----Original Message-----
From: Chuck Norcutt [mailto:chucknorcutt@xxxxxxxxxxxxxxxx]
Sent: 17 May 2013 22:26
To: Olympus Camera Discussion
Subject: Re: [OM] Oly 4/3 vs m4/3 lens mounts and adapters
I tried the focusing stage since Wayne said he'd gotten such an arrangement
to work with his Pen and, if it worked, would require nothing more than what
I already have.
I didn't come up with your solution since I've never completely read the
bellows description in the eSIF which is, I think, the only place that tells
you that the back of the lens board is threaded. But it looks like you need
to re-read it yourself :-) since the thread is for a Series VI filter and is
not a 49/55 filter thread. Nevertheless, your solution should work given
the right bits and pieces.
But re-reading the eSIF to understand what you had written caused me to
think about reversing the lens which might provide a bit more room to
maneuver since it moves the thick base of the lens board to the back side.
Maybe. Thanks for the memory jog.
Chuck Norcutt
On 5/17/2013 5:35 AM, Piers Hemy wrote:
> I may have missed something obvious, but why are you using the
> focusing stage? Remove the rear standard (camera mounting board) and
> bellows from the bellows rail, and use the 49/55mm filter threads on
> the back of the front standard (lens board) to mount the OM-D. You'll
> need a 55mm m4/3 reverse adaptor such as 271191801433 on the auction
> site, and a female-female filter adaptor such as this:
> http://www.camera-filters.com/index.php?main_page=product_info&cPath=4
> 31&pro
> ducts_id=7214
>
> You may also need a blank filter ring to get extra separation, but I'm
> sure you'll work that out!
>
> Piers
>
> -----Original Message-----
> From: Chuck Norcutt [mailto:chucknorcutt@xxxxxxxxxxxxxxxx]
> Sent: 16 May 2013 18:04
> To: Olympus Camera Discussion
> Subject: Re: [OM] Oly 4/3 vs m4/3 lens mounts and adapters
>
> I'm removing the grain of salt. I mounted the E-M5 on the focusing
> stage, installed the OM adapter and some OM extension tubes and then
> put the OM body mount from the bellows onto the end of the tubes.
> Running the body mount into the bellows connector resulted in the E-M5
> setting in a non-level position on the focusing stage. I think my
> guess of 3mm (maybe 2mm) vertical misalignment may be about right but
> it's not the height of the body or lens center lines.
>
> I had assumed that the OM body was lower and would align properly.
> Nope, the two camera's lens centers appear to be at the same height so
> an
> OM-1 on the focusing stage doesn't align either. The problem of
> vertical misalignment is caused by the height of the focusing stage.
>
> Chuck Norcutt
>
>
> On 5/15/2013 11:15 AM, Chuck Norcutt wrote:
>> A quick and very rough measurement looks like the vertical centerline
>> of the E-M5 is about 3mm higher than an OM body. But take that with
>> a grain of salt. Also, like the E-P1 the tripod thread is off center
>> from the lens center by about 9mm. That, however, could likely be
>> solved by drilling and tapping a new hole in the focusing stage.
>> I'll take a better measurement later since this has some promise.
>>
>> Chuck Norcutt
>>
>>
>> On 5/15/2013 8:17 AM, Wayne Harridge wrote:
>>> G'day Chuck,
>>>
>>> Something like this should work:
>>>
>>> http://www.structuregraphs.com/RandomStuff/15-May-2013/index.html#20
>>> 1
>>> 30515-A
>>> .jpg
>>>
>>> OM focussing rail with slide copier attached E-P1 with om -> m4/3
>>> adapter and 50/3.5 @1:2
>>>
>>> The only problem with this is that the E-P1 tripod thread is not
>>> below the optical axis of the lens. Vertical alignment is ok. What
>>> is the situation with the E-M5 ?
>>>
>>> To get good contrast you'd probably need to cover the gap between
>>> the lens and slide copier with a dark cloth.
>>>
>>> ...Wayne
>>>
>>>
>>>
>>>>
>>>> Thanks, Wayne. That answers my question; the 4/3 mount is not
>>>> physically compatible with the m4/3 mount. But I'm afraid OM tubes
>>>> won't solve my problem. My problem is that the OM->m4/3 adapter is
>>>> already too long for what I'm trying to do with the bellows and
>>>> slide copier. I can't connect
>>> with
>>>> the slide copier using tubes alone and adding tubes to the bellows
>>>> would make the problem worse.
>>>>
>>>> Steve Barbour sent me links to the 4/3->m4/3 adapter (thanks,
>>>> Steve) but that won't help me either. I would still have to
>>>> connect that up to an OM adapter which gets me right back to the
>>>> length problem I'm trying to overcome.
>>>>
>>>> What I need is an OM->m4/3 adapter with a 15-20mm section sawed out
>>>> of the middle. The 80/4 is probably the right solution but I don't
>>>> have one
>>> of
>>>> those. :-) I'll have to think about this some more. What I need
>>>> is
>>> something
>>>> like an m4/3 lens flange glued directly to the back of an OM body
> flange.
>>>> Basically an m4/3->OM adapter without the tube between the two mounts.
>>>>
>>>> Chuck Norcutt
>>>>
>>>>
>>>> On 5/14/2013 11:28 PM, Wayne Harridge wrote:
>>>>> I tried to mount one of my OM->4/3 adapters on my E-P1 - too big.
>>>>> I'm not surprised actually as I reckon Oly would have copped it
>>>>> from a whole lot of customers who mounted a 4/3 lens on an m4/3
>>>>> body and
>>>> found it didn't focus.
>>>>>
>>>>> Perhaps pick up some cheap OM tubes, they seem to be plentiful on
>>>>> that auction site.
>>>>>
>>>>> ...Wayne
>>>>>
>>>>>
>>>>>>
>>>>>> Can someone who has both systems verify whether or not a 4/3 lens
>>>>>> fits on
>>>>> a
>>>>>> m4/3 camera? I know it won't focus properly and maybe not even
>>>>>> operate electrically. My only real concern is whether a 4/3 lens
>>>>>> (or OM to 4/3
>>>>>> adapter) physically fits into an m4/3 body.
>>>>>>
>>>>>> The reason I ask is that I was trying to use my OM bellows and
>>>>>> slide
>>>>> copier
>>>>>> today to see if I could copy slides onto my E-M5. To do that I
>>>>>> need a magnification of approx 0.5X. If I had a Zuiko 80/4 short
>>>>>> mount macro
>>>>> lens for
>>>>>> the bellows I'd be OK. But my only two macro lenses are my
>>>>>> 90/2.5 Viv S1 and my 50/3.5 Zuiko.
>>>>>>
>>>>>> I don't think I can get the 90/2.5 to work at all since at 0.5X I
>>>>>> think
>>>>> the image
>>>>>> of a slide is somewhere beyond the length of the bellows rail.
>>>>>> The 50/3.5 macro is only designed to do about 0.68X on the
> bellows.
>>>>>> The bellows itself prevents it from getting to 0.5X. The
>>>>>> limitation is
>>>>> imposed
>>>>>> by the minimum separation of the lens board and camera mounting
>>>> board.
>>>>>> According to my possibly dodgy calculations the image plane needs
>>>>>> to be brought forward about 14mm. If you were using an OM or 4/3
>>>>>> body that wouldn't be possible. However, I note that the 4/3 to
>>>>>> OM adapter is about 20mm shorter than the m4/3 adapter. If I had
>>>>>> a 4/3 adapter on the m4/3 body I think that would give me the
>>>>>> extra range I need to bring the image plane in and get the 50/3.5
>>>>>> to do 0.5X or
>>> slightly
>>>> smaller.
>>>>>>
>>>>>> So, can someone answer the physical compatibility question
>>>>>> between the two mounts, ie, will a 4/3 lens fit onto a m4/3 mount
>>>>>> even though it might not actually work electrically and certainly
>>>>>> can't focus even if it
>>>>> physically fits?
>>>>>>
>>>>>> Assuming it does, anyone got a spare OM to 4/3 mount you'd like
>>>>>> to move on? Maybe an old one with no AF confirmation chip? I
>>>>>> won't be needing anything like that.
>>>>>>
>>>>>> Chuck Norcutt
>>>>>> --
>>>>>>
>>>> __________________________________________________________
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>>>>>
>>>> --
>>>> __________________________________________________________
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>>>
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