Olympus XA - Understanding if focus works

Francesco-p · Jun 25, 2016

Hello,

I've recently purchased a used Olympus XA. Upon the initial inspection everything seemed to check out: shutter and aperture work, rangefinder behaves correctly, meter appears to react correctly and light seals appear to be in good shape.

When i got back home and started to play a little more and I noticed that when changing focus, there is no reaction in the lens itself. This is looking both from the front of the camera or from the back when opened.

Basically the focus lever does not generate any visible movement in the lens. Is this normal?

Thanks,
Francesco

Jesper · Jun 25, 2016

It's normal. Just put a film in it and enjoy the camera.

benjiboy · Jun 25, 2016

The lens focuses by moving the internal elements.

ransel · Jun 25, 2016

If you hold the camera at an angle, looking at the front of the lens, move the focus lever, you can see very slight movement inside the lens, like just a mm or two difference.

Francesco-p · Jun 25, 2016

Not even that actually....in other small compacts I have i can actually see a slight movement in the lens area.

I guess I'll actually have to burn a test roll.... oh well. Thanks for the input!!

Jesper · Jun 25, 2016

You will find a lot of useful info about the different XA models at http://www.diaxa.com/xa.htm, including a description of the lens:
"The Olympus XA´s non-collapsible 35mm f/2.8 Zuiko lens uses an optical construction, that is, to put it mildly, unique. This six-element, five group optic is best described as a reversed retrofocus wide-angle lens which has been modified to shorten its overall length (approximately 31mm from front element to film plane) compared to its focal length in a manner resembling that of a true telephoto. In order to be able to cover 24 x 36mm format, large rear elements are necessary, and, for rigidity as well as shallow depth, internal focusing (by moving the third optical group back and forth) was selected."

thuggins · Jun 28, 2016

Francesco-p said:
Not even that actually....in other small compacts I have i can actually see a slight movement in the lens area.

I guess I'll actually have to burn a test roll.... oh well. Thanks for the input!!

There is nothing to "burn". As noted above, your XA is functioning normally. All the XA's focus internally, with the exception of the XA1 which is a fixed focus.

Apart from the innovation of a lens that is physically shorter than its FL. the XA also introduced the sliding dust barrier (which is often referred to by any number of incorrect and nonsensical names). If the XA were to focus by moving the entire lens it would interfere with closing the dust barrier. It would have also likely required increased travel of the dust barrier to allow clearance for the lens barrel. This would have increased the overall size of the camera, which went against its entire design philosophy.

Mainecoonmaniac · Jun 28, 2016

The camera is fine. I gone one from my local thrift store and it's my favorite film point and shoot. The lens is very sharp with great vignetting. One quirk I want to tell you is that the needle inside the camera indicating the the shutter speed is off with mine. However, the exposure is spot on with my camera. So just ignore the shutter speed indicator. The camera is a great design.

nosmok · Jun 28, 2016

MCM, there are TWO meters in an XA-- one feeds the display, the other exposes the film. One or the other can be wrong, but it's better to have the display meter off of course.

Chan Tran · Jun 28, 2016

Yeah that's really the Olympus way. They did the same thing for the Olympus OM-2. 2 metering circuits one for display and 1 for the exposure.

summicron1 · Jun 28, 2016

I just shot a test roll with an Olumpus XA3 and was very favorably impressed. Sample:

Richard S. (rich815) · Jun 28, 2016

summicron1 said:
I just shot a test roll with an Olumpus XA3 and was very favorably impressed. Sample:View attachment 159794

So nice! We should start an Olympus XA thread with images from the XA series...

Ricardo Miranda · Jun 28, 2016

nosmok said:
MCM, there are TWO meters in an XA-- one feeds the display, the other exposes the film. One or the other can be wrong, but it's better to have the display meter off of course.

Are you sure about that?
Where are the 2 meters located? I can only see one.
Thanks!

summicron1 · Jun 28, 2016

Ricardo Miranda said:
Are you sure about that?
Where are the 2 meters located? I can only see one.
Thanks!

I've heard this before. I could only see evidence of one in the repair manual, but the shutter and needle definitely work independently.

A few years back I dropped my XA and the needle in the window quit working -- but the shutter still seemed to work fine, as subsequent shooting proved. So I went that way a couple of years until I dropped the camera again.

Yup. Fixed the window needle. The camera finally died of wear/love/age, or something, but I have spares thanks to the local thrift stores.

summicron1 · Jun 28, 2016

More images from the XA 3 I tested -- I was unsure of the zone focusing, but it seemed to work well enough. A 35mm lens with a max lens opening of 3.5 really has good depth of field.

AgX · Jun 29, 2016

Chan Tran said:
Yeah that's really the Olympus way. They did the same thing for the Olympus OM-2. 2 metering circuits one for display and 1 for the exposure.

Agfa also did so with many models. There both sensor lenses are prominently placed next to each other.

Mainecoonmaniac · Jun 29, 2016

Here are my XA shots. It's such a simple camera.
https://www.flickr.com/photos/mainecoonmaniac/21396589639/in/dateposted-public/
https://www.flickr.com/photos/mainecoonmaniac/21557295316/in/dateposted-public/
https://www.flickr.com/photos/mainecoonmaniac/20962366203/in/dateposted-public/

thuggins · Jun 29, 2016

Ricardo Miranda said:
Are you sure about that?
Where are the 2 meters located? I can only see one.
Thanks!

Describing the camera as having "two meters" may be a bit of a semantic subtlety. The camera has one meter, in the sense that a meter has a D'Arsonval type movement, an indicator, and a scale for the indicator to be referenced against. This is the meter that is visible in the display of the XA, and it has nothing to do with the exposure of the camera. As the XA has an electronic shutter, there is a separate circuit that sets the exposure. This is why an XA can give perfect exposures when the meter display is wrong. This is apparently a pretty common problem as my XA has this same issue and I've seen it mentioned a number of times thru the years.

This is not the same as the OM-2. The 2 (and the 4's) do have two sets of photocells; one drives the meter visible in the viewfinder and also indicates the approximate exposure that will be used in auto mode. But once the shutter is fired the second cells take over as part of Oly's ingenious OTF (Off The Film) system. This reads the actual amount of light hitting the film and keeps the shutter open until the proper exposure is achieved.

Richard S. (rich815) · Jun 29, 2016

Mainecoonmaniac said:
Here are my XA shots. It's such a simple camera.
https://www.flickr.com/photos/mainecoonmaniac/21396589639/in/dateposted-public/
https://www.flickr.com/photos/mainecoonmaniac/21557295316/in/dateposted-public/
https://www.flickr.com/photos/mainecoonmaniac/20962366203/in/dateposted-public/

Wow! Love those.

Ricardo Miranda · Jun 29, 2016

Tim,

Thanks!
So, the XA only has one meter.
What you described for the -2/-2N is correct.
Not so much for the -2SP/-3/-3Ti/-4/-4Ti as these have only a cell at the bottom of the mirror box and a secondary mirror.

Chan Tran · Jun 30, 2016

thuggins said:
Describing the camera as having "two meters" may be a bit of a semantic subtlety. The camera has one meter, in the sense that a meter has a D'Arsonval type movement, an indicator, and a scale for the indicator to be referenced against. This is the meter that is visible in the display of the XA, and it has nothing to do with the exposure of the camera. As the XA has an electronic shutter, there is a separate circuit that sets the exposure. This is why an XA can give perfect exposures when the meter display is wrong. This is apparently a pretty common problem as my XA has this same issue and I've seen it mentioned a number of times thru the years.

This is not the same as the OM-2. The 2 (and the 4's) do have two sets of photocells; one drives the meter visible in the viewfinder and also indicates the approximate exposure that will be used in auto mode. But once the shutter is fired the second cells take over as part of Oly's ingenious OTF (Off The Film) system. This reads the actual amount of light hitting the film and keeps the shutter open until the proper exposure is achieved.

The XA has photocell the drive the galvanometer and 1 photocell that controls exposure time. The OM-2 has 1 photocell for the galvanometer display and another to control shutter time too. Not too much different there.

Ricardo Miranda · Jun 30, 2016

Chan Tran said:
The XA has photocell the drive the galvanometer and 1 photocell that controls exposure time.

Then, would you be so kind as to prove what you said by showing where the 2 cells are located, preferably in a schematic from the factory, please?

As I said above, only the original -2 and the -2n have 2 blue SPD cells on the bottom for the Auto exposure and 2 (CDS on the -2, there are reports the -2N has SPD cells) cells next to the viewfinder for the viewfinder and Manual exposure.
So, yeap, that's 4 cells!

Chan Tran · Jun 30, 2016

Ricardo Miranda said:
Then, would you be so kind as to prove what you said by showing where the 2 cells are located, preferably in a schematic from the factory, please?

As I said above, only the original -2 and the -2n have 2 blue SPD cells on the bottom for the Auto exposure and 2 (CDS on the -2, there are reports the -2N has SPD cells) cells next to the viewfinder for the viewfinder and Manual exposure.
So, yeap, that's 4 cells!

On the circuit diagram. P201 is for the meter galvanomter and P101 is for shutter speed control
On the part list near the bottom is listed 2 CDs photocell for the 2 functions
On the part location shows the 2 of them next to each other so basically both looking at the same scene.
Why do you think it's possible to control exposure automatically without a light measuring circuit?

Ricardo Miranda · Jun 30, 2016

Thanks! That clarifies it.

Chan Tran said:
Why do you think it's possible to control exposure automatically without a light measuring circuit?

I don't. Where did you get the idea?

Chan Tran · Jun 30, 2016

Ricardo Miranda said:
Thanks! That clarifies it.

I don't. Where did you get the idea?

Because you said there is only 1 sensor. If there is only one sensor then how the automatic exposure control measure light? Most cameras use the same sensor or sensors to display and control exposure. Since we all agree that the indicator in the viewfinder is totally independent then there must be 2 sensors.

Olympus XA - Understanding if focus works

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