RJ Camera FD adaptor

I've been using a few FD lenses on my G1 and been reasonably happy with the adaptor that I have been using. You can read about that adaptor here.

There were a few issues I had with that adaptor and how it fitted onto the lens as well I had felt that it would be nice to have an adaptor which allowed me open and close the aperture iris without needing to fiddle with the lens aperture ring.

Someone wrote to me suggesting that jinfinances adaptor (the adaptor shown here) had exactly this in his latest model.

I asked jinfinance (the eBay seller) and he seemed not to be sure if it did or if it did not, however he was kind enough to lend me one for me to review on my blog and to answer my question.

So, the answer is yes it does. The adaptor has some interesting features which I'll describe.

The physical:

If you look carefully at the above image you can see a groove which allows the lens iris operation coupling pin to move. Its operated by grasping the grip ring just behind the lens mount and turning it a few degrees. This is perhaps also visible in the image below.


and in close up



This then operates the mechanical stop down lever on the lens to close the aperture to the size you've set on the lens aperture control.



Why would you want to do this? Well it does make it easier to focus with the lens wide open (especially if its dim) and its also easier to pick exactly where critical focus is with the lens fully open too.Since I've been using an adaptor without this feature for some time I was keen to see if it would make a significant difference in operation.

As I've been using OM lenses I have essentially had the same operation by removing the coupling pin from the adaptor and using the Depth of Field preview button that is standard on the OM lenses. This has shown me that sometimes its handy, and sometimes its not. Particularly I find that when working on a tripod photographing birds at a nest, or when trying to follow focus small ducklings that its not. Either I'm trying not to shake the camera or just too occupied with othe controls.

When working with photographing people with mid range lenses its handy. However with the FD lens (unlike the OM lens) and on this adaptor I need to rotate a ring rather than press a button. In this case I found that it is not as neat a method and gets in the way of foucs and operation.

The reason for this partly due to the ring being so close to the aperture, partly due to the ring being stiff to turn, and partly due to it being all quite cramped in there.

This image shows a couple of things; firstly don't snack on oily chips when handling a matte black camera for photography.

Ahem ... well nyway, the already snug space between the grip and the lens is taken up a bit more by the adaptor. Personally I can get my fingers in there, but I'm sure what the people who complain that the camera is tiny (NB with big fingers) may have a different report. Looking at this using my other adaptor you can see the difference.



maybe its easier to see this when morphing from one adaptor to another



Essentially the RJ adaptor is wider than the base of the lens.


There is one last important point in the physical, that is concerning mounting the adaptor and engaging the aperture diaphragm or iris when you mount the lens on the adaptor.

The RJ adaptor gets around a problem which seems to afflict all of the other FD lens adaptors, by having the rotating ring around the outside to engage and disengage the iris control this adaptor gets around the problem of needing to engage the FD iris coupler during the mounting process and the iris coupling is engaged by turning the ring after mounting.


To mount the adaptor and then engage the iris coupler you there is a green dot (visible on the first picture), line this up with the red dot on the chrome part and also red dot lens. Then mount and turn the lens normally. The iris is then engaged and stopped down by turning the ring on the outside of the adaptor (which moves the engaging pin as in the diagram above).

One of the things I've notice with the other adaptor (and indeed this one if you don't decouple before dismounting) that some of my FD lenses are a bit difficult to unmount. In particular when using extension tubes this is quite important, as I can't take my lens off and add a tube without using this system.

This means that with the RJ Camera adaptor and using macro extension tubes I can start with an extension tube which I think is about right (but perhaps a little short) and I can then add another tube without taking it all apart. By decoupling the iris, I can simply remove the lens (leaving extension tube and adaptor on the camera) add another few mm of extension tube onto my stack and put the lens back on. This can be a pain, but lately I've been getting pretty good at guessing first hit what extension I need. This makes me wonder if the design is intended to give aperture operation or simplify mounting?

Either way this ability to couple and uncouple the iris provides macro and extension tube users with a significant benefit.

So from the physical side:

• its well made,
• looks great has,
• gives manual control over the aperture and
  
• is easier to mount and dismount a the lens

Infinity Focus

To test this on this adaptor I used my FD 28mm lens, as the shorter focal lengths are more sensitive to the precision of the adaptor length than longer focal lenghts are. What I found was that with the lens wide open that the RJ adaptor is a little short of infinity. The bottom image is the RJ and the top is the Ciecio7 adaptor...



Its not huge, but the RJ adaptor is not reaching infinity. When I first got the Adaptor from Ciecio7 I found that it too was not focusing at infinity, and I found that the solution to this was to lap down the front surface. Given that design was a single piece of alloy turned down the right shape, it made sence to simply hone down the front surface. However with this lens I'm not sure if I'd like to do that.

summary

I like both these adaptors. I'd be tempted to modify the RJ adaptor to bring in infinity focus. Having discussed previously my thoughts on the adaptor and infinity focus issues I don't think its a significant issue. Certainly by f8 you can't really pick much difference. Is it significant to you? Well I guess it depends on how much you take landscape images of infinity using f2.8

I thought I'd leave you with a side by side of the two adaptors. To me the RJ adaptor is s very nice looking piece of gear that does the job, provides nicer mounting and un-mounting and the ability to open and close the iris for focus and taking with out moving your aperture ring. The Ciecio7 adaptor is more simple both in looks and operation, but then its also cheaper and does the job just as well. Both need some honing to have them infinity focus perfectly.


the rest is your call :-)

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post scriptum: infinity focus revisited - problem solved

I received an email from RJ Camera asking me to check that the adaptor plate was properly torqued down and asking me to check again the infinity focus.


He felt that this may make the difference. It is after all only small fractions of a mm we're talking about so I pulled out my jewelers screwdriver and found that I could indeed torque it down about 1/3 to 1/2 a turn on each of the three screws.

I then put on the lens and took another shot ... sure, the lighting has changed, but this is now compared to the image from the Ciecio7 adaptor (the top one in the previous comparison) and its more or less identical. Here is a 100% pixel view:


So, this means that before you get concerned about your infinity focus, to check that all the screws are properly tightened.

But I advise you to be quite careful in doing this.

• Do not apply too much pressure on your screwdriver or you may strip the thread (it is into aluminum after all)
• use a proper sized screwdriver (most hardware stores and many supermarkets sell a small set for less than $10)

Once you are happy with focus, I would recommend putting the smallest amount of some kind of thread lock cement on them to prevent them from vibrating loose in future. Perhaps it is something which the manufacturer could consider?

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:-)

porvoon siili

I was at Porvoo this weekend (which was nice but the weather was typically Finnish. Here's a sample image of the docks).



anyway, as we were driving out to go sight seeing something shuffled across the road fast.

and we both said "hedgehog".

But this time it was a big male, and I was not going to let him get away without getting a closer look. So armed with some gloves I keep in the car I went and found him in the bush.

He immediately curled up into their distinctive little ball and was absolutely not going to come out while I was holding him (would you?)

So I put him on the grass and we sat back and waited for him to relax.

While he was waiting he seemed to be taking occasional deep breaths and releasing them slowly, just like when people are pissed off and waiting not so patiently ... sigh ...

So he sat curled up like a bundle in a sleeping bag made of prickles and waited. With his eyes tightly shut.


we thought it was best to put him back in the hedge and go back to what we were doing ... after all he might have been on his way to something important, and we wouldn't want to make him late.

adapting a lens to fit the mount

an old engineer friend of mine once said "if it jams force it, and it breaks it needed replacement anyway" (thanks Paul).

With this philosophy clearly in mind I had a go at fitting my lens onto a new adaptor I bought on eBay in an attempt to mount a Computar 12.5mm f1.3 TV lens onto my G1. I bought the adaptor from a fellow on eBay called hawkpeng2003. I've previously bought RJ Cameras adaptor which worked for another lens, but not this one.



The Computar wouldn't fit in the recess (by a long shot) and RJ Camera said it couldn't be done.

The bottom of my lens looks like this:


and comparing it to the RJ Camera mount:


it just clealy wasn't going to fit.


Well, the diagrams from Hawkpeng2003 on his site looked promising, particularly this one:




Here is my adaptor (and the lens in the background)

The dot you see on the lower left is the alignment dot. Note also the chamfer on the contcentric inner edges of the mount. The actual dimensions of the lens matched the dimensions of the mount in the diagram above from HawkPeng2003, but it did not take into account the square edges on the lens, and his adaptor has chamfered edges.

All of them other edges on the lens were within the sizes he quoted except one ... the second inner edge.

So armed with my trusty Leatherman I set to work to carefully grind that second inner edge back. Here's the result:



Now, prior to working I used some masking tape around the mounting thread to form a protective 'tube' which I pinched off. This was just to keep filings and finger prints off the lens.

Now as you can see the lens and the mount will go together better:


and boy, its close as you can see ... but the chamfer matches (well perhaps its got some clearance too).


but it fits and finally I can screw it down properly so that the alignment mark comes very close to perfect.




the final check is that the alignment mark on the adaptor comes quite close enough to that of the lens to give me quite good infinity focus (even with the magnifier).

Thanks HawkPeng

Have fun.

micro 4/3 adapter review: OM mount (Ciecio7 model)

Right about now there is a lot of interest in the micro 4/3rds format with enthusiastic amateurs and perhaps some professionals looking at using legacy lenses on these cameras. Not only is this a cost effective in terms of accessing some fine optics but the adapters are not being made by Panasonic but by many third party groups.

I think this is great as both the photographic community and specialist makers are getting involved in expanding this system. Now not that the makers produce lower quality stuff (in fact quite the opposite) its just that they don't always have the imagination or the inclination to cater to markets like this.

So, here is the adapter from Ciecio7, he's an ebay seller.



Its a nice tidy unit and looks quite nicely made. These adapters are really quite simple animals, and essentially simply stand the lens off from the camera to the right distance. This is because the micro 4/3rds system requires the lens mount to be 22mm from the sensor while other cameras require a bigger distance (called flange distance).

The first thing I noticed when I put on my OM lens was how bloody stiff it was to turn and lock the lens. I mean really. I needed to turn the lens focus all the way round and get a grip on the rubber focus grip strongly. I thought I was going to rip it off.

Once mounted I checked infinity focus (with my Olympus 21mm f3.5 lens) and found that it was off by a bit on the scale. Infinity was at 3 meters on the scale. Now the shorter the focal length lens the more effect that any accuracy of the above flange distance comes into play. With a 21mm lens I reckoned this was about 0.09mm

So I had now two reasons to pull apart the adaptor:

1. fix that tightness
2. fix the infinity focus

Fixing infinity focus

Infinity focus was easy to fix, I put a small sheet of shim material of the right thickness between the chromed plate and the black tube surface it screws to. His design makes this easy to do this.

Fixing the tightness

This proved a little more challenging, and required me to understand what the problem was.

If you look carefully at the mount you can see that the flaps on the back of the lens bayonet mount slide under some wing rails on the inner part of the mount.

This holds the lens from falling off the camera and also allows the lens to be tightened down against the front surface of the mount.

For it to tighten down it needs some spring to pull it against the inner surface of the lenses flaps.

if you look carefully at the mount to the left you can see that he's incorporated that into the mount.

I've removed the metal front mount (undo those 4 screws and pay attention to orientation) and you can see it more clear in this closeup of the metal part.


perhaps you can see that what he has done is to split the inner coupling flange and bend it down to provide a a spring as the lens bayonet flap moves under it from left to right (as you rotate the lens on the mount). From this angle you can see the delicate side cut he's put into the ring to allow it to be bent down.


But this is the problem, because this provides way too much spring power and friction. Its not needed and makes the lens so difficult to attach and remove I'm genuinely afraid of damage.

How is this done on the camera? Well since the OM mount method is quite similar to the Panasonic (only the sizes vary a little) I thought I'd just show you how the Panasonic does it. You can see below that a small curved bit of spring metal is inserted in a carved out part.


this applies a more delicate but sufficient force to properly tighten the system. Something else you'll perhaps noice is the red flecks of paint in there. This is something I've found with his other adaptors that the red paint he uses for marking the orientation points for mounting the adaper on the camera are not sufficiently countersunk and bits are cut off by the process. You can guess that these end up inside the camera. I think that this needs reviewing in his design and manufacture as its not a problem with other makers adaptors.

So, placing this plate onto my lens (but I can't turn it) you can see here just how much spring force is applied. In my opinion it was way too much (even though its barely a mm).



partly this is because of the thickness and the width of the spring and partly its because its bent a bit too strongly.

My solution was to carefully lapp down the underside of the ring to make that spring less strong. Like this:

I did this carefully with "wet and dry" paper and checked it against my lens (cleaning carefully each time) before finally remounting with my shim (from above) in place.

Conclusion

While I think that supplying users with a selection of shim material for allowing owners to easily tune infinity focus. This is a good solution to the problems of manufacturing tolerances, however it may not be for everyone. However without doubt this level of "owner adaptation" to get the mounting plate to interface with the lens is just too much to ask.

I would urge Ciecio7 to reconsider his design and either provide a smaller spring tension (by bending it less strongly) or reduce the thickness of the bent component (making it less stiff).

I'd also suggest that he consider more appropriately recessing the red dot so that it doesn't wipe off on the inside of my camera. This is not confined to just this adaptor either, as looking at my FD adaptor from him you can see the same thing happening there too



So there you have it.

Right now Ciecio7 is (as far as I know) the only maker producing an OM to micro 4/3rds adaptor which is one part, so this alone makes his adaptor worth looking at. If you don't mind it being 2 pieces, Jinfinance on eBay (known also as RJ Camera) presently makes a system which allows you to cover 2 lenses in one go. There might be advantages to that, but then again more joins means more likely hood for inaccruacy to me.

I have yet to get my hands on. It is more expensive than the one from Ciecio7 and I don't find having a two piece design ideal ... I'd rather have one adaptor for each lens. But then that's me :-)