Splendid stuff, Chuck, it all does now make sense in a way that eSIF
and SIF (which I also reviewed) don't even approach. It was late, I
didn't follow my own advice to just try it!
Piers
On 18/05/2013, Chuck Norcutt <chucknorcutt@xxxxxxxxxxxxxxxx> wrote:
> You're inferring stuff rather than actually measuring the bellows. I
> have done my due diligence and discovered that the eSIF is perfectly
> correct. The reason that a Series VI is used is that hole is supposed
> to take a filter... a Series VI size filter... which Wiki tells me thus:
> Series number Filter size Adapter ring
> VI 41.3 mm 44 mm
> My handy dandy millimeter rule tells me that the thread on the back of
> the lens board is (whaddya know) 44mm. I discovered that very quickly
> since no 49mm filter would fit there. That threaded hole is
> specifically for a filter and not for reversing lenses.
>
> Once again, the bellows manual tells you nothing about that filter
> provision. Your confusion about reversing lenses I think comes about
> from assuming that it's done the way you would on a camera body by
> attaching two lenses together joined by a male threaded ring with
> threads on each side to match the lenses to be joined. You've assumed
> that the 49/55 adapter is one of those rings... but it is not. It has a
> totally different function and isn't really 49mm on one end.
>
> Once you turn the front lens board around you don't need any sort of
> threaded adapter since the OM lens mount on the lens board is now facing
> the camera. Just install the lens on the normal lens mount and it, like
> the lens board, is now reversed. Where the 49/55 adapter comes in has
> to do with attaching the bellows itself to the lens. The attaching ring
> normally attaches to a ring on the back of the lens board that is about
> 51mm diameter... or the outside diameter of a lens having a 49mm filter.
> When you reverse a lens having a 49mm filter the bellows attaching
> ring fits over the lens in the same way as it does the ring on the back
> of the lens board. But when you use a lens with 55mm filter the lens is
> too large. It needs a step-down ring. Now, since I have never seen one
> of these step-down rings I can only conclude that it has a 55mm thread
> on one end and a 51mm unthreaded ring on the other such that it presents
> the same diameter to the bellows attaching ring as the ring on the back
> side of the lens board.
>
> Or something like that. If you know something else correct me.
>
> Chuck Norcutt
>
>
>
>
> On 5/17/2013 6:23 PM, Piers Hemy wrote:
>> 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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>>>>>
>>> --
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