Saturday, 27 June 2009

RJ Camera FD adaptor

Bottom line first:

This adaptor is cheap and will get your lens onto your camera, but its mechanically flimsy and the multi part construction with poor quality screws leading to issues with accurate alignment are the weak points. If you value adapter accuracy, reliable build and high quality then look to the ciecio7 (a polish eBay seller) adapter on eBay. I have been using his for some time now and they are machined from a single billet of alloy. They are robust and reliable and very well priced. note: I have nothing to do with ciecio7, I just like his gear. See my views on the free market Invisible Hand.

He has been iteratively developing them for some time and you can find my posts on those adapters here. At the time of writing this blog post I was initially quite unable to say what I wanted without an amount of whinge from the Chinese ebay seller. As this post is still popular I thought I'd add this 'prelude'. The rest remains as it always has been.

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 anyway, 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. As readers of my blog may recall, I already have an adaptor from Ciecio7 , looking at that adaptor you can see the difference between the two.



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 and its a little bulkier.


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.


In my view the Ciecio7 is great value for money (being cheaper), is simply and solidly made and gives me more room for my fingers between the lens ang the grip. The RJ adaptor has the bonus of being able to engage and dis-engage the aperture coupling during mounting (making some things easier as mentioned above) and allows you to open and close the aperture without changing its settings (should that be important to you)

The rest is your call :-)




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?




:-)

Sunday, 21 June 2009

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).

porvoo 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.

Friday, 12 June 2009

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've previously bought an Elgeet lens and RJ Cameras adaptor which worked fine, and looked like this.

Elgeet mounted on G1

But the Computar wouldn't fit in the recess (by a long shot) and RJ Camera said it couldn't be done. So I bought another adaptor from a fellow on eBay called hawkpeng2003, which I expected would be close ... what follows is my small journey to get it going...

The bottom of my lens looks like this:
C mount measurements

and comparing it to the RJ Camera mount:
c mount problem

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 file 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).

Here it is on the camera

G1 with 12.5mm f1.3 Computar

and it takes great images

P1030892

Thanks HawkPeng

Have fun.

Wednesday, 10 June 2009

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

FD 50mm On Adaptor

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 :-)

Tuesday, 9 June 2009

comparing legacy 35mm adapted fifties

One of the great things about the micro 4/3rds cameras (and as of this moment there is only the G1) is that not only do they make using older manual 35mm lenses possible, they make it easy. On the 4/3rds sensor camera good old 50mm lenses become nice medium portrait lenses, with these being as cheap as chips (and often you'll have one floating around) its really quite attractive to add one to your camera.

However, some decades ago I changed over from using more or less manual cameras to the modern Autofocus cameras like the Canon EOS, for one reason or another I just don't have any manual focus gear anymore. So if you're like me you might not have any manual 50mm lenses lying around.

But never fear eBay is here, and there's a whole wealth of stuff to choose from.

So, where to start?

Background


Well, back in the 70's and early 80's when 35mm SLR cameras like the Pentax MX or the Olympus OM-1 were the cameras to have I used Olympus. I liked the OM-1 and I personally thought that the 50mm f1.8 was quite a good standard lens. Years later I bought into the Canon EOS system and have been using it since 1989 with (at first) film bodies and (later) digital bodies.

When Canon changed from FD series to EOS they changed a few things which meant that FD lenses couldn't be used on EOS bodies without an adaptor which required a lens in it to correct for the different distance between the lens flange and the camera body mount (with the EF mount being some 2mm longer). This seemed to be a show stopper for many and FD lenses just dropped away in price with eventually the entire series becoming worth peanuts.

It wasn't just because of the change to digital either, as many people keep using Pentax and Nikon lenses on their digital bodies even though they do not have autofocus (just see eBay for some market price comparisons in the same focal length).

Being a Canon user (and hearing many glowing stories from some professional Canon users I knew pre EOS) I thought "why not pick up some bargains" for putting onto my G1.

Remember that micro 4/3rds is significantly smaller than a 35mm film frame, and so the "crop factor" means that the angle of view of a lens is essentially equal to a lens with double the focal length.

What this means is that if I want to see what 50mm lens looks like in a 35mm camera viewfinder I need to put a 25mm lens on it.

Well Canon don't make and FD 25mm, but they do make a 24 and a 28. Since the 28 is much cheaper than a 24 I thought I'd go for a 28mm and a 50mm pair of lenses and an adapter to fit them onto the G1.

For one reason or another (a future blog article on this one) I have decided to start re-acquiring Olympus lenses, the humble old Olympus 50 f1.8 is among my first. Naturally I wanted to compare the Oly to the FD and see what was what.

Method



Unlike comparison back in the film daze this was going to be easier, cheaper and more accurate. To even the comparison field even more (we're already using the same sensor on the same camera) I decided to do the following:
  • mount the camera on a tripod
  • use RAW capture
  • use dcraw to decode the files in a uniform way
  • focus on the same point using the "zoom tool" in manual focus
  • take images at f1.8, f4 f8
It seems that the 'crowd' using lenses by adapter seem particularly fond of shooting wide open. I can understand that for trying to obtain shallow DoF more in line with what one expected on 35mm (well so few of us remain these days, and full frame is too exotic for most folks) but it is often the worst to show what any lens can do ...

Since these lenses typically only work in stop down mode (meaning that the aperture is closed down just like when the camera takes the picture) it is more difficult to obtain your focus precisely on what you are wanting to focus on when focusing at f8.

While the G1's wonderful EVF certainly makes that easier by compensating for brightness you still end up focusing when using the greater depth of field, making critical focus more difficult (more on that later). So for these tests I focused at f1.8 using the manual assist magnifier in the EVF for very accurate placement of the focus plane.

Results

So, first an overview of what I photographed with the Olympus OM 50mm @ f1.8


Then the Canon FD 50mm @ f1.8


even at this overview size its clear that the Olympus lens is much sharper than the FD lens and has better contrast too.

Now for all images I focused on this patch of yellow flowers. Please click on any of the images to load a full 100% pixel screen snapshot that I've loaded.


The image above is at f1.8 and in my opinion the Oly is just streets ahead. Lets look at some other apertures.

f4




f8



At f4 the gap is closing, and by f8 its nearly gone, but you know, the little Oly 50 is still just that bit better. The funny thing is that the FD 50 is the same design as the "Nifty Fifty" prized by EOS shooters presently while the Zuiko 50 f1.8 was occasionally known as the standard body cap. Anyway, before we get to any conclusions, I'll show you the rest of what I found.

While we're at f1.8, lets look at the upper middle left of the image.


then at f4



then at f8


the gap is certainly closing, and if you weren't looking at a digital capture I'd say that any differences would well be lost in printing. But if you have to make a call, the Olympus 50 is still ahead to me.


The Olympus is so far better than Canon away from the center, so lets look right at the center (where both lenses should be at their best)

f1.8




f4





Conclusions



No matter where you look in the image the olympus lens performs better at every f-stop (the one below is at f8).


Now this brings back memories of the times (I was in my 20's then) and I remember many people saying that Olympus (Zuiko) lenses were by and far the best lenses short of Leica lenses.

It really leaves me asking just why it is that Canon developed such a market lead. Was it:
  • the better automation in their bodies?
  • price?
  • professional perception? (all those Olympic games and Footy matches)
  • ignorance of people in being able to compare lenses?

I can't be sure of that, but what I am sure is that FD lenses are not a match for Zuiko lenses

Since I've got a couple of other duplicate focal lengths I'll be making comparisons with other Oly and FD lenses in future pages. As well I'll publish soon a comparison of the Olympus 50mm on my EOS body compared to the EF50 f1.8

meantime, I hope that this has made your legacy 50mm lens purchase decision easier.

PS:

This was essentially the first comparison I did with adapted lenses on micro43 (and look at the date in the URL). I have subsequent to this put together some other comparisons of 50mm lenses which can fit onto micro43 cameras with an adapter here. That article focuses on contrast and flare, but also shows the differences in contrast. If you are interested in adapted lenses on micro43 you can find some other articles of interest here on:
 (although there will be some overlap in those tags)

:-)

Monday, 8 June 2009

Telkkä poika

As spring moves into summer there's lots of new activity round the local ponds.

These cute little fellas are skimming around the ponds like little speed boats!

Perhaps unlike other birds, they're quick on the uptake of getting food for themselves, and this one is just eyeing off what's in the water below about to dive down and get a mouthful of something.

I don't know what they're powered by but they seem to motor along at quite a few knotts for a little ball of fluff.

Mother ducks like this Telkka (golden eye ducks) are busy keeping an eye on what moves around the water edge as raising their kids isn't an easy job for a single mother and for some reason Dad is not around with these guys.


But hey ... at least they feed themselves