Monday, 23 November 2015

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

Tuesday, 17 November 2015

Asahi Pentax MX

This is a very nice, if rather simple, compact film SLR from Asahi. It is intended as a professional camera and gives full manual control of exposures. In fact, all the camera uses the battery for is the light meter and it works fine with no battery.

Pentax MX (c) John Margetts
lens: n/a
focal length:   n/a
apertures: n/a
focus range: n/a
lens fitting: Pentax K mount
shutter: cloth focal plane
speeds: 1 to 1/1000
flash: hot shoe plus 2 PC sockets
film size: 35 mm

The layout of the camera is pretty standard for SLR cameras from between 1960-ish and 1985-ish. The top plate is metal (as far as I can tell. The three ME series cameras from Asahi had metallised plastic top plates). On the right is the film advance lever. This is metal with a black plastic tip. When not in use, it returns flush with the top plate. In use, it sits slightly proud. This allows easier access for your thumb when advancing the film and also allows easier access to the shutter speed dial. In front of the film advance is a window to the frame counter. This automatically resets to -2 (shown as S) when the camera back is opened. The counter then counts up from zero - two frames being used to remove the film fogged when loading the camera.

Next on the top plate, right at the front, is the shutter release button. This is chrome plated metal and is threaded for a standard cable release. Around this is a moveable collar. When turned anti-clockwise, it turns off the light meter and locks the shutter release. However, the shutter itself is not locked as it can still be fired using the self-timer. In the off/locked position, a small red 'L' is revealed to remind the photographer to unlock the camera.

Pentax MX (C) John Margetts
On the left of the shutter release button is a very small window to an indicator for the shutter status : white = not cocked/not ready
red = cocked/ready

Next along is the shutter speed/film speed selector dial. Shutter speed is set by simply turning the selector dial to position the required speed against the red mark - speeds are from 1 second to 1/1000 seconds plus B. To select the film speed, it is necessary to press a small button on the dial and turn.

Next is the pentaprism hump. This has a hot-shoe accessory shoe on top with then usual central electrical contact. It is marked with a red 'X' to signify that it is synchronised for electronic flash. For flash bulbs, there is other provision.

To the left of the pentaprism hump is the rewind crank. As had become usual by the time this camera was made, the rewind crank pulls up to both unlock the rear door and to free the film cassette for removal.

The front of the top plate is graced with the letters MX which are embossed in the metal and the name Pentax above the lens mount.  The Asahi logo and the name Asahi appear on the front of the pentaprism. Immediately above the name Pentax is a small window. This allows the set aperture to appear in the viewfinder above the image. Below the letters MX is the self-timer lever. This is activated by turning it anti-clockwise (which winds up the timer spring) and then pressing the small button revealed by moving the lever. This gives an eight to ten second delay and also (as mentioned above) will fire the shutter even when locked by the collar around the shutter release button.

On the other side of the lens mount are two PC connectors. One marked FP for flash bulbs and one marked X for electronic flash. These allow for off-camera flash as well as giving provision for using flash bulbs. These come with black plastic caps to protect the contacts when not in use.

The rear of camera is rather plain. There is the viewfinder eye-piece and the rear door. This door is opened by pulling up on the rewind crank. The door is made from black painted steel - on my camera, much of the paint has worn off and the steel has started to rust. In the centre of the door is a holder for the end of the film carton to act as a reminder as to which film is in use - an item all film cameras should have.

The base of the camera is intended to have a rapid wind attachment fitted and to accommodate this there are two holes to act as locating devices and a covered linkage to the film advance mechanism. As I do not have this rapid wind attachment, I can say no more about it. Also on the base plate is a covered battery compartment. This holds two button batteries - those fitted to my camera are marked 'GPA76'. Fortunately, Pentax did not rely on mercury batteries and these batteries are readily available.

The only other thing to mention is the lens mount. This is a K mount camera and any K mount lens will fit and work with the single exception of modern digital lenses with no aperture ring which, while fitting, will not be able to have their aperture adjusted. There are no electrical contacts on the MX version of the K mount as this is a fully mechanical camera but it does not mind lenses with contacts. I have three K mount lenses - a Tokina zoom, a Ricoh Riconar 55mm and a Sirius Automatic 28mm. All three work well with this camera.

Test pictures.

I am quite pleased with these - no light leaks, shutter working as it should - no pin-holes in the curtains and no hesitating curtains. In the second to last photo, there is severe vignetting. this is caused by me using a lens cap designed for a 50 mm lens with a 28 mm lens - the vignetting is actually the lens cap in view!

 This next one shows the joy of using the wrong lens hood - severe vignetting!