Asahi Pentax ME-F

Pentax were the leading 35 mm SLR cameras through the 1960s and 1970s. During the 1980s, there were a lot of technological advances (not just in photography) and Asahi (the makers of Pentax cameras) were leading the push to develop modern automatic cameras.

The act of producing cutting edge, state of the art cameras necessarily meant also making mistakes. There were a number of innovative dead-ends during this period and the result was that Asahi lost their lead as prime camera makers to Nikon and Canon.

With this particular Pentax model the innovation was auto-focus. this was the first consumer auto-focus camera but using a technique that did not prove to be very effective. Asahi's next auto-focus camera approached the task very differently. As I only have the camera body and not the special auto-focus lens I can make no comment about how well the auto-focus worked in practice.

This Pentax ME F is a development of the Pentax ME Super - itself a development of the Pentax ME. The ME series of Pentax cameras were introduced in 1976 with the ME. The ME Super was introduced in 1980 with the added option of manually setting the shutter speed and this ME-F in 1981. Other M series Pentax cameras were the MG, MV, MV1 and MX.

The M series were smaller and lighter than the Spotmatic and K series cameras - following the lead of Olympus with the OM series of cameras. They also all had aperture-priority automatic exposure (the MX had entirely manual exposure).

lens: none supplied

focal length:  n/a

apertures: n/a

focus range: n/a

lens fitting: Pentax Kf mount

shutter: Seiko metal focal plane

speeds: 4 seconds to 1/2000 seconds

flash: hot shoe and PC connector - X synch

film size: 35 mm

This camera measures 132 mm wide by 87.5 mm high and 50 mm deep not including the lens. It weighs 480g.

The top plate is fairly cluttered resulting in fiddly controls that my rather large fingers struggle to manipulate. On the far right, as usual, is the film advance lever. This moves through about 140 degrees to advance one frame but the first part of the motion - around 45 degrees - is required to engage the advance mechanism. The lever also has a secondary rest position which usually indicates the presence of a light meter switch - I do not know if this is the case with this camera, it could just be to make fast winding possible.

In front of the film advance lever is a window to the frame counter. This counts up from one. Opening the back resets the counter to -2 - indicated by an orange dot - which encourages you to waste two frames to get to frame one. I find I get get an extra frame in by starting at -1. To be honest, I actually ignore frame counters and just shoot until I cannot advance the film anymore which gives me 26 exposures from a 24 exposure cassette in the main.

Next to these is a large black mode dial. This locks in place and it is necessary to depress a (very) small white button to be able to turn the dial. For me, this is a two handed job and is the most awkward part of using this camera. The modes available are L, Auto, M, 125X, and B - more on these later. In the centre of the mode dial is the shutter release button. This fires the Seiko metal focal plane shutter.

Between this dial and the pentaprism hump are two small buttons which alter the shutter speed when in manual mode. These buttons are actually plenty large enough even for my fingers but they are in a rather restricted space. The pentaprism is of the size needed - there is not much scope fore reducing this in size as cameras get smaller as it still has to show the full 24 x 36 mm frame. On top of the pentaprism is am accessory shoe. At this date it is basically a flash shoe and has hot-shoe connections. This is a large central contact  allowing the use of any hot-shoe flash gun. There is also a small secondary contact for Pentax specific flash guns with added functionality. It is also possible to use a cold-shoe flash as there is also a PC (Prontor-Compur) connector on the front of the camera.

On the left of the pentaprism is a switch to activate the auto-focus function. This is useful even without the dedicated auto-focus lens as the camera has a focus confirm function with any lens. This switch has three positions - off, 2.8 and 3.5 The last two relate to the maximum aperture of the lens being used. Behind this switch is a second switch which turns the audible focus-confirm on or off.

To the far left of the top plate is the folding rewind crank. Around this is the film speed setting for the light meter. This ranges from 12 to 1600 ASA (ISO). 12 ISO seems very slow by modern digital standards but films available in 1980 were very slow. This setting is set be slightly lifting the outside of the ring and turning. This ring also sets exposure compensation from x4 to x1/4 (that is, +2 stops to -2 stops) which is set by turning the ring without lifting. Pulling up on the rewind crank itself unlocks the door.

The front of the camera is uncluttered. Right of centre (looking at the front) is the Pentax K mount bayonet fitting. this is an adaptation of the original K mount known as Kf mount as it has four sprung electrical contacts and one unsprung contact. These allow the camera to communicate with the special auto-focus lens. This is the only camera with this version of the K mount. There were later variations on the K mount with electrical contacts in other parts of the mount ring. All these are backwards compatible. I am successfully using a lens with the later version of the K mount with this camera. I lose the later functionality of the lens but it still works fine as a fully manual lens.

On the right side of the mount is a PC connector which allows the use of flash off-camera. On the left of the lens mount is a delay action lever. This is not connected to the shutter release button. First  you wind the mechanism by turning the lever down in an anti-clockwise direction. Second, you start the process by pushing the lever back up very slightly. The delay is about eight seconds.

On the back of the camera (which is made from painted steel) are three items. most obviously is the viewfinder eye-piece. This is nice and large and works well for those of us who wear glasses. When looking through the viewfinder you get the expected ground glass screen. In the centre is a ring of micro-prisms and a split-image centre to aid focussing. On the left of the viewfinder image is a vertical list of shutter speeds. These range from 4 seconds to 1/2000 seconds. The selected speed is indicated by a small green or orange LED. There is also a reminder at the top of the list if you are in manual mode. At the bottom centre of the viewfinder is a green hexagonal LED flanked by two red triangular LEDs. The red LEDs light when the lens (any lens) is out of focus and the green LED lights when the lens is in focus. There is also a noise if the switch mentioned earlier is on.

On the right of the rear of the top plate is a small window revealing vertical red and black bars. These 'dance' when you advance or rewind the film. The idea is that if the film is not properly loaded the bars do not dance saving you taking pictures with no film in place. Personally, I always watch the rewind crank turn for the same reason. However, the dancing bars do work.

In the middle of the back is a device that all film cameras should have - a holder for the end of the film carton. If, like me, you have more than one camera on the go at a time, it is easy to forget what film is in which camera. Below this holder are two more electrical contacts for the optional data back.

On the base plate there are a number of items. on the left under a round cover is a mechanical connection for an electrical film winder. Next to this is the button to release the rewind mechanism. In line with the centre of the lens is a 1/4 inch UNC threaded tripod socket (the old standard was 1/4 inch Whitworth which is as near as dammit to the modern standard). To the right of this is the battery compartment. This holds four button batteries which are still available today. Beyond the battery cover is a release button to undo the battery cover catch.

In use.

Loading film is as easy as it can be made short of full automation. The back is opened by pulling up on the rewind crank - as was usual with cameras of this age. The film cassette goes on the left - the rewind crank is pushed back down to hold the cassette in place - and the film is pulled across the camera and the leading edge is pushed between any two of the many white bars on the take-up spool. Very simple and hard to go wrong.

Above the white bars on the take-up spool is a fairly loose plastic ring. As the film moves past this ring when advancing the film, the movement in the loose ring is transferred to the red and black dancing bars. visible through the window on the back of the top plate. Once you have loaded the film and closed the back you need to 'waste' two frames as these have been fogged while the back was open. At this point, the frame counter should read '1' - remember to put the end of the film carton in the memo holder and you are ready to go.

The photographer needs to set his choice of aperture and focus the lens and the camera does the rest. The viewfinder is nice and clear and the split-screen centre works as it should.

This is a delightful camera to use. My only real niggle is turning the camera on. this involves pressing a very small white button on the black mode dial and turning the dial to Auto or M or 125x. The L position is off and this switches off the meter and locks the shutter release button - the shutter can still be fired in this position by using the self-times lever.

Auto reads the aperture from the lens and selects the most appropriate shutter speed - this is not restricted to the displayed speeds, any intermediate speed can be selected. The M mode requires the user to set both the aperture on the lens and the shutter speed using the two buttons next to the pentaprism - in this case only the displayed speeds may be selected.  The 125x speed is used to synchronise the shutter and the flash at 1/125 seconds. There is also a B setting which leaves the shutter open as long as the shutter release button is depressed. I find using this dial very difficult and have to use both hands. Once the mode dial is set, I leave it set until I have finished for the day.

To use this camera with the full complement of shutter speeds requires working batteries. If they are flat, the camera can still work in mechanical mode but this restricts the camera to 1/125 seconds shutter speed. This is clearly less than ideal but does mean that you can continue to take photographs if you have no spare batteries.

I do not have the auto-focus lens but the auto-focus system will give focus confirmation with any lens. this is in the form of a green LED indicating focus and two red LEDs which indicate the direction you need to turn the focus ring on the lens to obtain focus. I found these to be completely useless - they did work but the audible confirmation is rather more useful - actually, my eyes offer a faster focus confirmation.

Test photographs - Agfa Vista colour negative film.

Hand held, indoors 

A nosey of twitchers

Olympus μ Zoom 115 (also Mju Zoom 115)

This is a sophisticated point-and-shoot camera. It is clearly a development of Olympus's XA series. The camera opens by sliding a cover to the right, exposing the lens and switching on the electrics. Controls are minimal making it very much a point-and-shoot camera. In fact, it is quite possible to ignore the few controls provided and then you have a basic point-and-shoot with a 38 mm lens (and autofocus).

Closed/off

All of the controls are on top of the camera. On the far right of the camera is the zoom control. This defaults to the shortest focal length of 38 mm. This is slightly wide for a 35 mm camera but not excessively so. 'Normal' for 35 mm (the diagonal of the negative) is 43 mm. Pulling the control will zoom the lens to 115 mm (hence the name of the camera). A nice touch is that the viewfinder also zooms so the viewfinder image always matches the lens image.

Open/on

Next to the zoom control is the shutter release. This is a fairly large chrome plated button. This is easy to find by touch which is as it should be.

Next to the shutter release are two small chrome plated buttons. The front one sets the delay timer and the rear one sets the flash mode. There are six flash modes. Default is the flash firing when there is insufficient light without it. The first selectable mode is red-eye reduction where the camera fires a few low intensity flashes to make the subject's pupils contract before the main flash. The second mode is no flash - this allows you to take moody pictures in poor light. 

Third mode is the flash always on. This is for fill-in flash when the background is brighter than the subject. The fourth mode is night-portrait mode - this restricts the flash to illuminating the subject while leaving the background dark. The fifth mode is a combination of the first and fourth modes - night-portrait with red-eye reduction.

Next to these controls is a small LCD display. This gives minimal information: frame number, flash mode, delay on/off. To the left of the LCD display is a small pop-up flashgun.

Telephoto position (115 mm)

On the back is the viewfinder eyepiece. This has a dioptre adjustment so us spectacle wearers can use this camera without our glasses. Also on the back is a small window to allow the user to see what sort of film is in the camera - or, indeed, if there is any film in there at all. This is a simple but very useful facility for those of us with several (!) cameras as it is very easy to forget which camera is loaded with which film.

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Blog (c) John Margetts 2014
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On the base is a standard (1/4 inch UNC which is just about the same as the old standard of 1/4 Whitworth) tripod boss. This is right on the right-hand end of the camera. This is not a good place to have this (in the centre is better and under the lens node is ideal) but I doubt this camera ever gets used with a tripod. 

Also on the base is a recessed button to allow for rewinding the film before it is finished. When the film is finished, rewind is automatic.  The battery chamber is on the right-hand end of the camera. The battery is a CR123 lithium battery which is still readily available.

Back

I currently have a film in the camera and I will report on using the camera and the image quality when the film is finished.

20 September 2014

I have my test film back from Snappy Snaps and here are the results.  This camera is rather easy to use - the only real awkwardness I have experienced is that it is a bit small for my hands - then again, this is a compact camera!

Image quality is certainly good enough for snap shots, which is what the camera is really for.  I would not use it for serious photography, but I might carry it on those occasions when I do not want to be encumbered with kit - a night out, perhaps.

The first few are of a herd of cows/calves at Frampton Marsh RSPB nature reserve, Lincolnshire (near to Boston).  I am quite pleased with these - I like cattle - but the close-ups show a design weakness.  The camera is happy to take a picture when it cannot focus.  At the least, a warning would be nice.

This flower was blowing in the wind outside the visitor centre at Frampton Marsh. It has been captured fairly well - indicating that the automatic exposure system has selected a fast enough shutter speed. I have added a crop of the top flower to show how well the camera has captured detail - quite well, I think.  The graininess of the magnified picture will be a mix of the grain of the Agfa Vista + film and the medium quality scan I asked the lab to do.

Crop of the top flower.

This next picture was taken in poor light with mist in the distance. It is the British Sugar sugar beet processing factory at Bardney seen across a field of wheat stubble.

 

The next three are close-ups taken in a wood. The first is not very impressive - I cannot make out what the white blobs are although I suspect they were fungi of some sort.  The third picture is exposed quite well, but the first two show the limitations of the camera in challenging conditions.

The next is Lindum Hill in Lincoln. A bright but not sunny day - all seems to be well.

The rest are of Wells (in Somerset, not Wells-next-the-Sea in Norfolk I usually photograph). The camera has done well here - I could use this camera for street photography as it is quite discrete in use and works well in an urban situation.

Canon EOS 5 (A2, A2e)

Canon EOS 5 - front view

This is an early model EOS camera dating from 1992 to 1998. All EOS cameras have the same basic shape from the first film EOS (EOS 650) to the latest digital EOS . The main way in which the various EOS models vary is in size. This EOS 5 is a large and heavy camera. It weighs 665 g (with no lens, battery or strap) and measures 154 by 120 by 75 mm.

The EOS 5 was aimed at what is now called the prosumer market - that is, the lower-end professional and high-end amateur market.

The outside of the camera is black plastic - I think polycarbonate but I am far from certain about that. The weight of the camera clearly says that the camera has a metal chassis. The battery holder on the right acts as a grip and is covered in a rubbery material. The battery is a lithium 2CR5.

For its day, it has a lot of controls but very few compared to a modern digital SLR. The controls are in two places. The most used are on the top plate and the less used on the back.

On the far left of the top plate is a mode selector dial. This has the expected options for a serious photographer - Programme, Tv, Av and M. It also has DEP, x, CF and CAL - details later. On the opposite side of off ('L') are settings that declare this to be an amateur camera. Here are no words or letters, just icons. This offers four options: Portrait, Landscape, Macro and Action.

Next to the mode selector is a button to release the built-in flashgun. Once the flashgun is raised, this button allows you to set flash exposure compensation.

Towards the rear by the mode selector is the indicator for the position of the film plane.

Canon EOS 5 - top view

In the middle, as is usual with SLR cameras, is the pentaprism viewfinder.  This is an actual pentaprism - on lower-end EOS models, Canon used a penta-mirror which gives a smaller and darker image in the viewfinder. On top of this is the built-in flashgun. This is a sophisticated flashgun which has a zoom function to allow the best illumination of the subject. On top of the built-in flashgun is a Canon-specific hot shoe. I am not calling it an accessory shoe as I cannot imagine that anyone has ever fitted anything but a flashgun here.

The space to the right of the pentaprism is dominated  by an LCD screen. This displays various pieces of information depending on the set functions and the actions being carried out at the time. In front of this is a button to activate the self-timer which gives a ten second delay between pressing the shutter release and the shutter firing.

On the right, in front of the LCD screen, is the now ubiquitous selector wheel and in front of this is the shutter release. This last is a plain, smooth button - no cable release thread now.

On the back are more controls. On the top right are two buttons. The right-hand one allows you to set just one of the five autofocus points to be active - or all five. The left-hand one has two functions. Normally, it acts as the exposure lock. This allows you to point the camera at the most significant light source in your subject and then recompose without altering the exposure. Useful where too much sky will result in underexposure of the key elements. It is also used to toggle between 0 and 1 when setting the Custom Functions.

Canon EOS 5 - back view

In the centre of the back is a secondary selector wheel - this one has an on/off switch and it is not necessary to ever use it. On the left of the back are four more buttons. These are labelled 'Drive' (to select how many photographs are taken with one press of the shutter release), 'AF' (to select how the camera attempts to focus), '<icon>' (which selects the exposure metering system), and a multi-function button which allows you to override the ISO setting, set exposure bracketing, red-eye prevention, silence the beeper and, finally, allow multiple exposures on one frame. Right to the left is a window to allow you to see the cassette inside the camera. This is very useful to people with poor memory like me (although I prefer a holder for the film box end which allows you to add personal notes like pushed ISO rating).

On the front of the camera is the EF lens mount. As this is a 35mm camera, it is 'full frame' and will not accept the modern digital EF-S lenses. As is usual with EOS cameras, the lens release button is on the left of the lens mount.

To the right of the lens mount, towards the top of the camera, is an auxiliary light emitter for the autofocus system. This helps the camera focus in poor light.

On the right-hand end of the camera are three items - a button to rewind the film part way through, a socket for an electrical remote control and the catch for the battery compartment. The remote socket is of an older design - it has three electrical contacts - and is not compatible with the later remote controls with a jack plug.

On the left end is the catch for the back and a PC socket for a flash cable. The last (also known as a German socket) has become obsolete since this camera but its presence here means I can use any of my old flashguns as well as my Canon specific Speedlite.  The base has a connector for a motor drive and a standard (1/4 inch Whitworth) tripod socket.

Control details.

The mode selector has what has become standard (Tv, Av, M & P) but also has four extras. These are DEP, x, CF and CAL.

'DEP' is a system to optimise depth of field. It works by then user focusing on the nearest point of interest and pressing teh shutter release, then focusing on the furthest point of interest and pressing teh shutter release. At this point, the camera selects a focus point and aperture that will result in both these points being in focus. The user then presses the shutter release a third time to actually take the picture.

'x' allows for flash synchronisation with the PC socket. The user can select between shutter speeds of 1/200, 1/125, 1/90 or 1/60 using the rear selector wheel.

'CF' allows the user to set any of the custom functions. The only one of these I use is the custom function to leave the film leader out of the cassette when rewinding.

'CAL' is used to calibrate the eye controlled focusing system. I find this both useful and easy to use. The EOS 50e also has this system. I read reports on the Interweb about how poor this eye control focusing is but I suspect those people have not calibrated the system properly - or not at all.

In addition to these 'creative zone' settings (Canon's term) there are also 'image zone' settings. For anyone who understands the basics of photography these settings are unnecessary. Their big disadvantage is that they disable user control over shutter speed, aperture, focusing system, metering mode and flash. The only advantage to using image zone settings is that you can use the camera as a point-and-shoot camera with interchangeable lenses.  This also applies to modern Canon digital SLRs. The five image zone settings are full auto, portrait, landscape, close up and sport.

The button to release the built-in flashgun has two functions - it releases the flashgun and, when pressed a twice, it allows you to set flash exposure compensation. If an external flash is fitted to the hot shoe (rather than by way of the PC connector), the flash release button will not release the built-in flashgun but pressing it just the once will allow you to set the flash exposure compensation.

The built-in flashgun is rather sophisticated - at least when compared to the built-in flashguns on the EOS 650, EOS 50e, EOS 350D and EOS 650D. This flashgun has a zoom function and changes focus according to the focal length signal from the lens. This is supposed to optimise illumination for differing angles of view. You can hear this focusing of the flashgun taking place as you rotate the zoom control on the lens. I have not tried this out so I cannot comment on how well the flash illumination optimisation works.

This built-in flashgun also has a separate red-eye reduction lamp. The way this works, when set, is the subjects of a portrait are asked to look directly at teh flashgun and just before the shutter opens and the main flash fires, this small red-eye reduction lamp fires several times. Red-eye in flash portraits is caused by the pupil in the eye being dilated due to the low light level allowing the flash to enter the eye, bounce of the red coloured back of the eye and then going back to the camera. This red-eye reduction lamp causes the subjects' pupils to contract, allowing less light into the eye and even less reflected light to bounce out of the eye. So no more excuses for zombie-eyed portraits.

I like having the flash PC (Prontor-Compur) connector for using off-camera flashguns. For modern photographers this is obsolete as neither cameras nor flashguns have PC connectors, but I am not really a modern photographer.

I am not going to go over all the options available on this camera. As a computer-controlled camera, the options are legion, but there are a few things worth mentioning.

Film rewind is automatic at the end of the roll of film. This rewinds fairly slowly and retracts all the film into the cassette. This can be altered in two ways. Firstly, the rewind speed can be increased - useful at social functions where dead-time spent reloading the camera with film is not a good thing. Normally, slow rewind is better for the film (less scratches and less build-up of static to attract dust) but this is not always the most important thing. Secondly, you can set the camera to leave the film leader out of the cassette. This is what I was always taught to do as the presence of film between the velvet light seals of the cassette improves the blocking of light. It also makes it much easier to load the film into the spirals for developing.  It is also possible to force film rewind part-way through the roll of film. For an amateur, we are always going to finish all the film in the camera, but a professional is very likely to have a number of unexposed frames left at the end of an assignment.

Film speed is set automatically by the DX coding on the film cassette. If you are using Adox films (for example) with no DX coding or loading your own bulk film into reusable cassettes, you need to set the film speed manually. This is entirely as ISO (which I still think of as ASA) with no provision for DIN settings. Not a problem, really. If you are using DX encoded cassettes, you can still set the film speed manually - useful if you want to push the film speed.

This camera takes a single lithium 2CR5 battery. This is common with all my EOS film cameras - I have three currently and have previously owned three others. In normal use, this should last for about forty rolls of 24 exposure film. This battery life can be extended by not excessively refocusing the camera, not keeping your finger on the shutter release button too long, not using the eye-controlled focusing and turning the camera off if you are not actually using it. You can also seriously reduce battery life by doing the opposite of all those things.

test photographs:

Ivy flowers

 Field, Lincolnshire Wolds

Rockabilly Buskers, Lincoln.

Rockabilly Busker, Lincoln

Legacy lens adapters

In the course of collecting these old camera, I have also collected a number of old lenses, some of which are very good.

My Olympus OM10 camera has a Zuiko 50mm, f1.8 lens which six elements in five groups and a Vivitar zoom lens (75-205mm) which has a very good reputation.  I also have another Vivitar zoom lens (20-200mm) which doesn't have quite the same reputation as the other Vivitar but performs very well nonetheless.

My Zenit E came with the famous Helios-44 which is a superb copy of the Carl Zeiss Biotar (six elements in four groups) and my Praktica LT3 came with a Meyer Optiks Domiplan which is a triplet - so not in the Zuiko or Helios-44 league but a good performer when stopped down.

When thinking about a 50mm prime lens for my Canon DSLR, it occurred to me that I already had several good  50mm prime lenses and was there any point in buying another?

With this thought in mind, I looked into buying an adapter so I could use one of my old prime lenses (it would seem that these  have morphed into legacy lenses while i wasn't looking).

First, I looked into buying an adapter for my Olympus OM lenses.   There are a number of these available and they are quite cheap.  These range from simple metal rings with an OM female bayonet on one side and an EF male bayonet on the other - these cost £2 to £3 each - to more complex adapters with electrical contacts and a chip.  this is then one I bought and it cost me £12.99 including postage.

The adapter ring is very well made out of brass which has been chrome plated.  The EF bayonet fits smoothly into the Canon digital camera and, similarly, the Olympus lenses fit smoothly into the female side of the adapter.

When the lens, adapter and camera are all fitted together, the result is snug and secure.  There is no significant play, even with the heavy and long Vivitar zoom.    The electrical contacts make contact and the camera recognises the adapter.

The point of the contacts and chip is so that the focal length and aperture of the lens can be stored in the Exif data of the resulting digital file.  th achieve this it is necessary to programme the chip on the adapter.  t5rhis is actually quite easy - but not simple as it involves quite a few steps. Once the adapter is programmed for a particular lens, it is necessary to manually set the aperture on the lens and then separately set the aperture on the camera - this aperture is then stored in the Exif data.

If accurate Exif data is important to you, this process will be worthwhile (and will be necessary to repeat for each lens you use with the adapter) but I routinely ignore Exif data so I do not bother with the process.  If, like me, you want to be simple, you just focus the lens, set the aperture (you need the camera to be in Av mode) and let the camera select the shutter speed.

The adapter works well so long as you remember the lens is entirely manual - you need to focus and set the aperture for each shot.  Given that I use fully manual cameras a lot of the time, this should be second nature, but as soon as I pick up my digital DSLR I forget to worry about focus and exposure.

My next adapter is for M42 lenses (also known as Pentax fit, although developed by Zeiss Ikon in Dresden in the 1940s).

I had two M42 lenses when I bought this adapter - the Helios-44 Biotar copy and the Meyer-Optik Domiplan.  Both screwed nicely into the adapter but there is a problem with the Domiplan lens in that it is an automatic lens - there is a pin on the lens that must be depressed by the camera just before the shutter is released in order to close the diaphragm. The adapter leaves this pin alone so the Domiplan can only be used wide open.  

Actually, while trying to get this lens to work with the adapter, I noticed that the lens has a significant fungal growth on one of the inner glass surfaces.  This lens is now in the dustbin!

The Helios-44 lens worked well.  This adapter is a simple aluminium disc with no contacts or chip sop there is no need to set anything up.  The same working method as with the OM adapter is required - focus with the lens diaphragm wide open, stop down the lens to the required aperture and let the camera sort out the shutter speed.  As there are no contacts, no lens details are stored in the Exif data.

Both adapters are easy to use and work well.  Not being interested in the Exif data, I would have been better off buying a cheaper and simpler OM adapter, but the one I did buy was certainly cheap enough.

Theoretically, as the camera is metering the light through the lens it should give the right exposure regardless of the lens used.  It has been suggested to me that TTL meters do not cope well at low light levels so will give poor exposure at small apertures.  I have not found that.  Initially, using the OM adapter with the Zuiko 50mm lens, the camera consistently overexposed at all apertures with the highlights clipping in all photographs.  The cause of this is that I was not setting the aperture on the camera as well as on the lens so the metering system assumed - incorrectly - that the lens would shut down when I pressed the shutter release.

Repeating my OM test exposures with the camera set to f1.8, the exposures were fine with the histograms coming up well to the left with no clipping.  This setting of the aperture on the camera as well as on the lens is only a problem with chipped adapters - or you can do as I now will and keep the camera set to its smallest aperture.

When using the Helios-44 with its simple adapter, the exposure histograms were well to the left and without any clipping so giving usable photographs.  This is regardless of the aperture set on the lens.  With this adapter, it is not possible to set an aperture on the camera as the absence of contacts makes the camera default to f00

Test pictures:  first, the same scene at different apertures (after these, a focal plane test).

OM adapter with a Zuiko 50mm, f1.8 lens.

 

aperture f16

aperture f5.6

aperture f1.8

M42 adapter with Helios-44 58mm, f2 lens.

aperture f16

aperture f56.

aperture f2

Focal plane test:  in order to focus on infinity, it is necessary that the focal node of the lens is the right distance from the film/sensor.  For a 50mm lens, this distance is 50mm (in some designs, the node might be in front of the physical lens).  This distance is split in two.  The first part is the film/sensor to mount distance (obviously, this never changes) and the second part is the mount to node distance.  This second part is susceptible to being changed by the adapter.  If the mount is too thin, the lens will still focus on infinity but its near focus point will be further away than intended.  If the mount is too thick, the lens will focus on nearer objects ok but will not be able to focus on infinity.  It is this last that I want to check.  I am not too bothered if I cannot focus on an object two feet away but I am very bothered about not being able to focus on infinity.  To be clear, I had better define 'infinity' - for this purpose, it is anything over 50metres away.

First the OM adapter.  The first picture is a standard scene in Lincoln.  The second picture is an enlarged crop from the centre to critically check the focus.

detail from the centre

Now the M42 adapter.

detail from the centre

You can see by comparing the two details that the Zuiko is performing better at a distance.  I think I can safely say that this lens adapter is correctly placing the lens in the mount.  The detail from the Helios-44 photograph is a lot less clear - but I cannot say if it is down to the adapter or the lens performance.  It is certainly good enough to use.