Aria viewfinder information MM vs AE lenses

[jorgo]

I'm looking to replace a completely thrashed Canon manual focus system, and have pretty much decided on a Contax Aria + 28/50/85mm lenses due to the lens quality, size (mainly travel photography - landscape/portrait) and spot-metering capabilities.

In the manual mode, the manual (p. 112) states that the camera displays the aperture that you have selected and the meter-bar shows the over/underexposure information. This is great for me since I hate taking the camera away from my eye just to see what aperture I've selected.

Is this also the case for older AE lenses as well as the MM? The manual unfortunately doesn't distinguish between the two. I would have thought that this is *NOT* the case since the AE lens doesn't transmit enough information to the body for the camera to perform in a program or shutter priority mode.

Since I mainly use manual mode, the cost savings of the older AE lenses would be a boon assuming that they do provide *ALL* the same information in the viewfinder that the MM ones do. Otherwise, I'll have to bite the bullet and get MM lenses.

If someone could please confirm this, I would be most appreciate and off to the races on joining the small but loyal and very supportive ranks of Contax users!

 

[jim0266]

Erik, I just purchased a new-to-me Contax 167MT and a 28/2.8 AE lens. The 167 does show the selected aperture in the viewfinder with this lens. I would bet a large sum of money that the Aria will as well, but hopefully an Aria owner will chime in shortly to confirm.

 

[jim0266]

Erik, I just purchased a new-to-me Contax 167MT and a 28/2.8 AE lens. The 167 does show the selected aperture in the viewfinder with this lens. I would bet a large sum of money that the Aria will as well, but hopefully an Aria owner will chime in shortly to confirm.

 

[rico]

Erik,

First, good choice! You'll enjoy that kit.

I switch regularly between 50/1.4 MM and 28/2.8 AE on my Aria. Regardless of lens, aperture is always conveyed to the body, is correctly displayed in the VF, and permits aperture-priority exposure (Av) mode.

While Zeiss may have tweaked the optical formula for some lenses at the time of MM introduction, the sole improvement of MM itself is mechanical. The diaphagm lever of the lens was reengineered, allowing the body to stop down the diaphragm by controllable amounts. The lever action was also lightened. This era saw other Japanese makers adapting their lenses for the same reason, e.g. Minolta MC to MD.

I buy AE when cheaper, and when MM versions don't exist.

 

[brunom]

Erik,
I can confirm there is no difference.
When you use M or Av mode the aperture displayed in the viewfinder is the one you manually selected on the lens, regardless it is an AE or MM.
When you use Tv or P mode the aperture displayed is the one the meter system selects. The difference between AE and MM lenses is that, at the time you depress the shuter, the body is able to change the aperture with an MM lens and not with an AE.
The only difference between AE and MM lens is the aperture ring mechanism.
May I remember you that the aperture selected on the lens and the one displayed by the viewfinder are only metering information. Actually the lens is at full aperture (except if you depress the depth of field preview ).
As an Aria owner + 28/50/85 I won't say this choice is not excellent. But if you make street photography you should consider the pancake.
Cheers.
Bruno

 

[jorgo]

Gentlemen,

Thanks for the information - that's great news and a big cost savings!

Rico - it makes perfect sense about allowing the body to stop down the lens by controllable amounts in A and Tv... I wonder how accurate or robust that lever action is. Whenever people have exposure issues they generally blame the shutter, no? It could equally be the body not stopping down the lens enough (assuming, of course, you're in A or Tv).

 

[afranklin]

Hi Eric,

> Whenever people have exposure issues they > generally blame the shutter, no?

They typically blame the meter...but I blame the user, as s/he's the one who tells the camera what to do ;-)

Regards,

Austin

 

[neilb]

> Erik, usually, bodies that can stop down the aperture do so before opening the shutter, and they take a light reading after the aperture has stopped down. If there was any inaccuracy in the stopdown, then they adjust the shutterspeed accordingly. This way, any inaccuracy in the stopdown mechanism is automatically compensated. For cameras that meter off the film (OTF) during exposure, this is a freebie. Sorry, but I don't know whether the Aria works this way.

Neil

 

[afranklin]

> > Erik, usually, bodies that can stop down the aperture do so before > opening the shutter, and they take a light reading after the aperture > has stopped down. If there was any inaccuracy in the stopdown, then > they adjust the shutterspeed accordingly. This way, any inaccuracy in > the stopdown mechanism is automatically compensated. For cameras that > meter off the film (OTF) during exposure, this is a freebie. Sorry, > but I don't know whether the Aria works this way. > > Neil

Neil,

Can you name a camera that adjusts the shutter speed after stopping the lense down, when in shutter priority mode? The lense stopping down should be dead on accurate...or there is a problem...so I'm not sure any camera would do this.

Metering off the film is for TTL flash, I do not believe it is for regular ambient light metering.

Regards,

Austin

 

[neilb]

>

> Austin,

Nikon FA for sure, and I think F3. I thought it was pretty common, but perhaps I'm mistaken? Probably some Oympus OMs, because they measure light OTF during exposure, so if they have Tv or P mode then they would do it too, most likely. Many cameras meter off the film for regular exposure, not just for flash. No?

Neil

 

[afranklin]

Neil,

> Nikon FA for sure, and I think F3. I thought it was pretty common, but > perhaps I'm mistaken? Probably some Oympus OMs, because they measure > light OTF during exposure, so if they have Tv or P mode then they > would do it too, most likely. Many cameras meter off the film for > regular exposure, not just for flash. No?

Again, I believe that cameras don't meter off the film for ambient light reading, only for TTL flash exposure. I've got a Nikon FA brochure somewhere I can check out...and if I find I'm mistaken, I'll let you know...or if you have a (credible) reference you can point me to that shows this, I'd like to know about it.

Regards,

Austin

 

[rico]

Erik,

I expect the Av stop-down to be as accurate as the aperture ring, given the mechanics. For action specific to the MM feature (implements Tv and P), the accuracy will certainly depend on correct calibration of the camera body AND the lens.

Robustness of the levers is obviously a potential problem compared with a mount like Canon EOS (which has no such projections), but I have nothing bad to report. Mounting a C/Y lens is a bit fiddly, to be sure.

Neil,

My understanding from photo.net is that OTF gives the dynamic exposure adaptability you mention, but is a rare feature (Pentax LX, Olympus OM-2 and OM-4 may be it). The experiment is to fire Tv in a dark room, then turn on the lights: if the shutter stays open then there's no OTF. Meter beforehand to establish appropriate light levels. So far, I observe no OTF for RTS.

 

[blumesan]

Erik,
To get back to your original question, all of the information above is essentially correct although some of the remarks confuse me. I have an Aria and use both AE & MM lenses. Here is the scoop with AE lens mounted:

In manual and aperture priority (Av) mode the set aperture is displayed in the viewfinder and is also correctly communicated to the exposure computer. The latter is important because metering is done with the lens wide open and the computer must know what the aperture will be at the time of exposure.

If you have an AE lens mounted and accidentally select shutter priority (Tv) or (P)rogram mode the camera will ignore the mode selection and operate in aperture priority mode, behaving as described above.

If you have an MM lens mounted and select Tv or P mode, again the Aria meters the light with the lens wide open and only adjusts the aperture (and/or shutter speed) an instant before firing the shutter. Thus you can rely on the aperture & shutter information displayed in the viewfinder (just prior to exposure) to be the parameters used to make the exposure.

Hope this helps.

Mike.

 

[blumesan]

Austin:

<<Can you name a camera that adjusts the shutter speed after stopping the lense down, when in shutter priority mode?>>

In a sense, the Aria does this. In Tv mode, (using an MM lens) if a correct exposure cannot be acheived by adjusting the aperture, the selected shutter speed will be overridden (shifted). However, as you have pointed out, this all happens simuntaneously and before the shutter is released. There is no OTF metering in the Aria.

As for the Nikon FA; I have checked the manual and it uses OTF metering only for TTL flash exposure. Even in this case I believe the OTF metering information is used to adjust the flash duration rather than the aperture or shutter settings. I too am unaware of any SLR that alters the shutter / aperture parameters AFTER the shutter is released. But there are lots of cameras out there about which I know nothing.

Regards,

Mike.

 

[jorgo]

All -

Very interesting discussion.

In summary then, for both types of lenses, the set aperture is correctly displayed in the viewfinder and correctly communicated to the exposure computer (and presumably the D-9 databack as well). All metering for both types is done with the lens wide open.

Rico -

You're definitely right about the Pentax LX being able to adjust once the shutter's been tripped. (See

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)

The Olympus manual for the OM-4T doesn't fully detail this, but the specs indicate for cw-average 'TTL Direct "off-the-film" Light Measuring' which I presume is the same.

By the by - does anyone know what percentage of the image area the Aria spotmeter covers? I haven't seen numbers on this - as a point of reference, the OM-4T brochure says it covers 2%.

Cheers,

Erik

 

[blumesan]

Eric:
<<By the by - does anyone know what percentage of the image area the Aria spotmeter covers?>>

Someone wrote a review of the Aria (unfortunately I can't find the url) in which it was stated that the spotmeter covers an area slightly larger than the microprism circle in the center of the viewfinder. Hope this is of some help.
Regards,
Mike.

 

[rico]

I simply cheated, and referred to p.226 of the manual. The spotmeter covers the microprism collar, a 5mm dia circle. This circle is marked on all four Aria screens.

A 300mm lens is needed to achieve 1° spotmetering with an Aria.

 

[blumesan]

Hi Rico,
I was aware of what it says in the manual. Have a look at the review:

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where the reviewer states: "The microprisms indicate where the spot meter is most sensitive, but the spot is somewhat sensitive to a slightly larger area."
Don't know how he determined this.

Mike.