Aperture lock button

pfogle

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Hi all,

like most people, I occasionally get underexposed results - I think the R-D1 is fairly conservative with exposure so as not to blow highlights.

Also, like many people I often dial in 2/3 EV compensation - sometimes 1 stop.

It suddenly struck me that, with a DSLR, I usually take a reading off the ground, and then lock the exposure with the shutter button. I had completely forgotten (Doh!) that the R-D1 also has AE lock using the button on the back :eek:

I am now resolved to use this for a week, and I'll report back whether it actually leads to more accurate exposures without the hassle of dialling in compensation. More news soon...
 
All this M8 talk about excess IR sensitivity has also made me wonder if the R D-1's variable exposures might be caused in part by the meter cell reading part of the IR spectrum. Since the R D-1 (unlike the M8) has a reasonably effective IR blocking filter over its imager, this would lead to underexposure under conditions in which there's a lot of IR, but more-accurate exposures in conditions with low IR.

[Why? Well, if the meter sees more IR than the imager, IR-rich scenes would cause the meter to say, in effect, "Whoa, lots of light here! I'd better cut back the exposure!" while the imager, behind its IR-blocking filter, would say, "Hey, kinda dark back here..."]​

If anybody has just bought one of those front-of-lens IR blocking filters that are suddenly in such demand because of the M8's purple-blacks issue, it might be interesting to try it on the R D-1 and see if it makes the meter readings more closely match the desired exposure.
 
It`s a shame that the RD1 doesn`t lock exposure with a half press of the shutter button (all that does is switch the meter on) easier than holding that rear button in - I hoped the F/W update would have allowed this..

My guess the reason why the cam can be up to a stop underexposed is the same reason why the Fuji S2 does - it has a FULL FRAME Metering system and Centre weighted isn`t really C/W on a 1.5X crop at all but most of the frame - longer lenses such as 75 or 90mm meter brighter.. Yes it probably IS preserving highlights too but it`s way too much..

One thing handy about needing comp dialled in all the time when using A mode is that the Shutter speed dial isn`t stuck in the A mode and therefore no need to press that irritating button to move the dial ;-)
 
More on R-D1 metering

More on R-D1 metering

I did a search on "meter" to investigate this subject on the R-D1. Some of us have done the AE unlock mod. and this allows us to change exposure from AE to + or - compensation, with one finger, during composition, without distraction during the moment. Granted the AE is usually to the + side, and in some respects this center-weighted system forces us all to be in touch with relative exposure principles.

I read one post that described the metering as bottom weighted and did not understand until I found this:

http://www.cameraquest.com/voigtbmeter.htm

The R-D1 is exactely like the Bessa, good or bad.

My thought is how I liked the Leica way of the round white circle painted on the shutter curtain, and gave a partial spot/center-weighted reading. If you see where I'm going with this, any mod I do to the R-D1, I want it to be reversible, and wonder how the shape and size of the R-D1 white meter area would effect metering? Would a 10mm white circle on the shutter curtain give a correct reading of that 10mm image height on sensor?
 
jim_buchanan said:
My thought is how I liked the Leica way of the round white circle painted on the shutter curtain, and gave a partial spot/center-weighted reading. If you see where I'm going with this, any mod I do to the R-D1, I want it to be reversible, and wonder how the shape and size of the R-D1 white meter area would effect metering? Would a 10mm white circle on the shutter curtain give a correct reading of that 10mm image height on sensor?

I don't think it would, and I also don't think you'd want to try it!

First, why you wouldn't want to try it: Painting on a cloth shutter curtain (a la pre-M8 Leicas) won't hurt it as long as the paint isn't very thick. Painting on the blades of a blade-type shutter (a la R-D 1) will almost certainly gom things up -- the blades are very thin and delicate, and they have to slide over each other in a very confined space.

Second, why I don't think it would work: The R-D 1 has a lighter-colored shutter blade that helps define its sensitivity area, but the sensitivity also depends on the lens over the meter cell and how it's aimed. The current sensitive area doesn't match the area of the light-colored blade, so painting a different light-colored area presumably wouldn't make it match the light-colored area. It would change the meter's sensitivity pattern, all right, but not in any predictable way. At least that's my guess.
 
jim_buchanan said:
My thought is how I liked the Leica way of the round white circle painted on the shutter curtain, and gave a partial spot/center-weighted reading. If you see where I'm going with this, any mod I do to the R-D1, I want it to be reversible, and wonder how the shape and size of the R-D1 white meter area would effect metering? Would a 10mm white circle on the shutter curtain give a correct reading of that 10mm image height on sensor?

Now that I have an R-D1s and can look at the parts in question, I feel that I can now jump in the discussions :D

I think it must also be considered that the R-D1/Bessa meters were designed to read the entire white frame. Painting it black and leaving a small circle may lead the meter to "think" that everything is dark.

All this M8 talk about excess IR sensitivity has also made me wonder if the R D-1's variable exposures might be caused in part by the meter cell reading part of the IR spectrum. Since the R D-1 (unlike the M8) has a reasonably effective IR blocking filter over its imager, this would lead to underexposure under conditions in which there's a lot of IR, but more-accurate exposures in conditions with low IR.

It's not likely that the meter sensor would behave like that. Most of the cells used in light meters are quite, if not totally blind to IR light. This is reason why light meters are useless for IR photography. Imaging sensors are another thing- they are natively more sensitive to IR. When they show IR effects in the picture, it's just that they show more than, or differently, from what they eyes see.

Jay
 
R-D1 mapped meter area

R-D1 mapped meter area

Yes, I agree with you. Too many unkowns and unpredictable results are possible. Those shutter blades are very finely finished.

I find the whole assembly very odd. The horizontal shape of the meter area. The aiming of the meter cell down and to the left.

In fact, I have just mapped the meter sensitivity area within the 28mm frame lines. My light source is a desk lamp from 8 feet away. The brightest reading was set at 1/1000 sec. The frame was divided into 1/3s as the above referenced article suggests.

The article is accurate in describing horizontal low left metering. I can see how it would underexpose.

R-D1_meter area.jpg
 
Topdog1 said:
I think this link also gives a diagram of the metering patern:

http://www.cameraquest.com/voigtbl.htm

/Ira

The Bessa L is different than the R. It may use the same cell but the placement is at the bottom for the L and at the top for the R. In addition, the R cell is angled and the shutter curtain is painted differently. The Bessa L metering patteren in the link is for a L, not R as the graph and text indicates.


I believe I am correct on this.
 
jlw said:
......... If anybody has just bought one of those front-of-lens IR blocking filters that are suddenly in such demand because of the M8's purple-blacks issue, it might be interesting to try it on the R D-1 and see if it makes the meter readings more closely match the desired exposure.

I've found a B+W 486 filter can make up to 1/2 a stop difference with tungsten light.

Bob.
 
it boggles the mind

it boggles the mind

that they could not think to allow depressing the shutter half-way to lock the shutter speed, but rather put a brand new unintuitive button on the back.

still, that button is getting easier to use than dialing in EV when you know the exposure you want.

pfogle said:
Hi all,

like most people, I occasionally get underexposed results - I think the R-D1 is fairly conservative with exposure so as not to blow highlights.

Also, like many people I often dial in 2/3 EV compensation - sometimes 1 stop.

It suddenly struck me that, with a DSLR, I usually take a reading off the ground, and then lock the exposure with the shutter button. I had completely forgotten (Doh!) that the R-D1 also has AE lock using the button on the back :eek:

I am now resolved to use this for a week, and I'll report back whether it actually leads to more accurate exposures without the hassle of dialling in compensation. More news soon...
 
Would a half press of the shutter button have created a delay in the final shot? Just curious as the instant shutter fire of the R-D1 is most appealing.
 
no.

no.

not if implemented properly, as on the Hexar RF.

Sailor Ted said:
Would a half press of the shutter button have created a delay in the final shot? Just curious as the instant shutter fire of the R-D1 is most appealing.
 
jim_buchanan said:
Yes, I agree with you. Too many unkowns and unpredictable results are possible. Those shutter blades are very finely finished.

I find the whole assembly very odd. The horizontal shape of the meter area. The aiming of the meter cell down and to the left.

In fact, I have just mapped the meter sensitivity area within the 28mm frame lines. My light source is a desk lamp from 8 feet away. The brightest reading was set at 1/1000 sec. The frame was divided into 1/3s as the above referenced article suggests.

The article is accurate in describing horizontal low left metering. I can see how it would underexpose.

View attachment 37690
jim- this has to be the most bizarre metering pattern I've ever seen! No wonder it's so difficult to second-guess what the meter will do :eek:

thanks for a nice bit of work and a very useful insight.
 
jim_buchanan said:
My thought is how I liked the Leica way of the round white circle painted on the shutter curtain, and gave a partial spot/center-weighted reading. If you see where I'm going with this, any mod I do to the R-D1, I want it to be reversible, and wonder how the shape and size of the R-D1 white meter area would effect metering? Would a 10mm white circle on the shutter curtain give a correct reading of that 10mm image height on sensor?
IMHO, the M6 centerweighted metering pattern is still the best for intuitive rangefinder shooting. But painting such a pattern on a R-D1 or a Bessa shutter would not work without adjusting the meter, otherwise it would probably strongly underexpose.

RichC said:
I must admit, I sometimes - not wholly seriously - wonder about supergluing it in!
Same for me, too! And as for the aperture lock, I'd prefer the more intuitive shutter-half-pressure feature.

Topdog1 said:
I think this link also gives a diagram of the metering patern: http://www.cameraquest.com/voigtbl.htm
That's the old Bessa R and L metering Pattern - where the whole shutter is in light grey and reflecting almost the complete area. With the R-D1, the shutter has just one horizontal light grey stripe in the middle, which results in a definitely different pattern.

Didier
 
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