Comparing Sinar Booster 1 reading to Sony A7 spot reading!

Dazzer123 · Sep 27, 2023

Hi folks,

I'm as yet to take a picture with my P2, but the day is surely approaching!

A question: by way of experimentation, I'm comparing the meter reading I'm getting from my Sony A7 with the Booster 1 reading in front of the ground glass.

I'm shining one light at a bare wall and taking the Sony spot meter reading from the middle of that patch of light.

Then I'm metering the same patch of wall with the Booster 1 (lens stopped down to the working aperture), via a Minolta Auto Meter IVF.

My lens is a Sinaron WS 80° 1:5,6 f = 150mm MC.

These are the readings I'm getting:

Sony A7: 1/250 of a second at f5.6, at ISO400
Booster 1: 1/250 of a second at f5.6 (so, fully open), at ISO400

Sony A7: 1/100 of a second at f11, at ISO400
Booster 1: 1/20 of a second at f11, at ISO400
(shutter time for Sinar 500% longer!)

Sony A7: 1/20 of a second at f22, at ISO400
Booster 1: 1 second at f22, at ISO400
(shutter time for Sinar 2000% longer!)

This has got me somewhat confused!

Can anyone explain to me why the recommended shutter time seems to get exponentially longer on the Sinar as i stop down?

I guessing that the difference is because I'm not stopping down the Sony when i take the meter reading, but i am stopping down the Sinaron.

But this is how you're instructed to use the Booster 1, according to the manual.

Could anyone give me the idiots guide to using the Booster 1 correctly?

Or other nuggets of wisdom?!

Thanks!

xkaes · Sep 27, 2023

Looks like you need to read the manuals for the booster and the Sony.

First, you need the booster and the Sony to be reading the exact same thing. Their "spots" are probably of different sizes/angles.

Secondly, you don't provide us all the information that you have available -- such as what exposure mode the Sony is set to.

Assuming the first readings at f5.6 are correct, both the Sony and the booster are producing erroneous results when stopped down -- they should be about 1/60 at f11, for example.

The Sony estimates the exposure while wide open, the booster while stopped down -- apples and oranges.

Plus, the Sony has a different lens than the booster -- apples and oranges.

You need to set up a test comparing apples to apples.

Instead of running tests comparing the two systems, test each alone -- to figure out what's going on. Your results for each are not correct.

Nokton48 · Sep 27, 2023

Once you get the Booster playing nice, you will then no longer have to bracket exposures.

I'd use that rather than the A7 for metering.

Dazzer123 · Sep 27, 2023

Thanks for the reply!

Sony is set on manual mode.

Angle is the same. Size is going to be very similar and anyway, i'm pointing it at a bare wall lit evenly over a large area.

Does the fact that it's a different lens matter so much? That wouldn't explain a 2000% difference.

I'm not sure if i'm comparing apples with oranges, for the simple reason that i'm sure you could give an experienced LF photographer a Sinar P2 and only a Sony A7 for metering and they would be able to take a correctly metered exposure!

Dazzer123 · Sep 27, 2023

Nokton48 said:
Once you get the Booster playing nice, you will then no longer have to bracket exposures.

I'd use that rather than the A7 for metering.

I wasn't particularly planning to use the Sony for metering!

It's just that when i tried the Booster 1 according to the manual, it was telling me such long exposure times, i was really doubting it, so decided to compare it to the Sony, hence my highly scientific test!

grain elevator · Sep 27, 2023

No idea of the device, but this reads like the sinar thinks it's still meteriing wide open and adding extra exposure for stopping down to the working aperture that it's already metering at.

xkaes · Sep 27, 2023

If you set your Sony to A mode, and the aperture to 5.6, your should get a speed of 1/250.

If you then set the f-stop to f11, you should get a recommendation of 1/60.

Do you? If not, you need to figure out what's wrong with the camera or lens or methodology.

Exactly the same with the booster.

To do any "highly scientific test", you need to first make sure your equipment/instruments are working correctly. From what data you have provided, neither are.

Dazzer123 · Sep 27, 2023

grain elevator said:
No idea of the device, but this reads like the sinar thinks it's still meteriing wide open and adding extra exposure for stopping down to the working aperture that it's already metering at.

The numbers do indeed seem to neatly suggest that!

But i don't get it: i thought the whole point of the Booster 1 was that you would measure with your working aperture, filters, bellows extension etc etc. in order to get a super accurate meter reading.

If the meter is going to give me these nutty, much-too-long exposure times when stopped down, i don't see the big advantage!

xkaes · Sep 27, 2023

I'm familiar with a Gossen large format meter -- which I assume is similar to yours -- and it worked exactly as you are hoping. That's why I asked if you have the manual.

I'm unclear what "The numbers do indeed seem to neatly suggest that!" means.

Do you mean you tested the Sony, as I suggested, and it's working fine or not?

We are not looking over your shoulder, so you need to be very specific. For example, can you specify the angle of view of the Sony and the booster? My guess is that they are not reading the same thing -- I don't care if it is a white wall.

grain elevator · Sep 27, 2023

Dazzer123 said:
The numbers do indeed seem to neatly suggest that!

But i don't get it: i thought the whole point of the Booster 1 was that you would measure with your working aperture, filters, bellows extension etc etc. in order to get a super accurate meter reading.

If the meter is going to give me these nutty, much-too-long exposure times when stopped down, i don't see the big advantage!

Do you input the working aperture on the Booster? If so, just don't and see what it reads?

wiltw · Sep 27, 2023

In OP, are ALL of the readings (f/5.6, f/11, and f/22) under the same condition of "I'm shining one light at a bare wall and taking the Sony spot meter reading from the middle of that patch of light. Then I'm metering the same patch of wall with the Booster 1 (lens stopped down to the working aperture), via a Minolta Auto Meter IVF."?

I ask that simply because...
f/5.6 vs. f/11 vs. f/22 sequence should follow the -2EV difference in aperture selection, with corresponding offsetting by +2EV in times... 1/250 vs. 1/60 vs. 1/15. IOW fully equivalent exposure combinations would be

1/250 f/5.6
1/60 f/11
1/15 f/22

and yet

the Sony reading is sequentially giving exposure series that is 0EV vs. +1.33EV vs. +1.66EV
and the Booster reading is sequentially giving exposure series that is 0EV vs. +2.66EV vs. +4.33EV

IOW NEITHER is registering the correct progression of +2EV of time difference to offset -2EV of f/number progression (f/5.6 vs f/11 vs. f/16)

Dazzer123 · Sep 27, 2023

xkaes said:
Do you mean you tested the Sony, as I suggested, and it's working fine or not?

The Sony is working fine, I'm not questioning that!

I think i may have worked out the problem: although Sinar claim(ed) that the Auto Meter IVF worked with the Booster 1, it's not mentioned anywhere in the manual.

So although i followed the manual's instructions i now realize there's one setting which isn't available on the Auto Meter (only on the Flash Meter). So i suspect that the Auto Meter only works with the Booster 1 like a typical analog camera meter (meter wide open, extrapolate your desired settings from that).

The thing is, i ordered a Flash Meter IV from Japan but it's been stuck in customs for 2 weeks, so i sourced a cheap Auto Meter locally because i was too impatient ....... but i think this is what's tripping me up.

If my Flash Meter ever actually arrives, I'll test it and report back!

Dazzer123 · Sep 27, 2023

wiltw said:
In OP, are ALL of the readings (f/5.6, f/11, and f/22) under the same condition of "I'm shining one light at a bare wall and taking the Sony spot meter reading from the middle of that patch of light. Then I'm metering the same patch of wall with the Booster 1 (lens stopped down to the working aperture), via a Minolta Auto Meter IVF."?

I ask that simply because...
f/5.6 vs. f/11 vs. f/22 sequence should follow the -2EV difference in aperture selection, with corresponding offsetting by +2EV in times... 1/250 vs. 1/60 vs. 1/15

yet the Sony reading is sequentially 0EV vs. +1.33EV vs. +1.66EV

and the Booster reading is sequentially 0EV vs. +2.66EV vs. +4.33EV

IOW NEITHER is registering the correct progression of +2EV of time difference to offset -2EV of f/number progression (f/5.6 vs f/11 vs. f/16)

I noticed that the Sony meter showed correct exposure (+-0.0) on both 1/60 & 1/100 of a second for f11. So i guess i wasn't being too careful with my metering or something!

xkaes · Sep 27, 2023

Dazzer123 said:
I noticed that the Sony meter showed correct exposure (+-0.0) on both 1/60 & 1/100 of a second for f11. So i guess i wasn't being too careful with my metering or something!

This is why I asked what MODE you were in when using the Sony. You should be in A mode -- and adjusting the aperture. That gives you a shutter speed -- no +/- needed.

Please tell us what shutter speeds you are getting in A mode at f5.6, f11 & f22. They should be exactly as wiltw wrote. If not, don't waste your time comparing it to the booster results.

And as wiltw wrote, it looks like you are not using the booster correctly. I use a Minolta Booster II with a Minolta Auto Meter II, and Flash Meter II and they all work fine together.

I can't speak to your Sinar booster -- it might have been made by Minolta -- but my guess is that you are simply using it incorrectly -- as wlitw and grain elevator have suggested.

The fact that your booster and camera both agree on the shutter speed when the lenses are at f5.6 indicates this.

If there is something you don't understand in the user manual, please ask.

wiltw · Sep 27, 2023

xkaes said:
The fact that your booster and camera both agree on the shutter speed when the lenses are at f5.6 indicates this.

The instruction for using Sinar Booster 1 with Minolta Autometer IVf

"Single point reading ambient light:

1. Set measuring mode to “AMBI” by using the

“MODE” button and select an approximate correct

shutter speed “TIME” by using the up-down con-

trol.

2. Place the measuring window of the Booster 1

on the point to be measured.

Stop down

the lens to working aperture.

Switch the Booster 1 on.

Shield focusing screen against straylight.

Press the measuring button on the Autometer IV F.

3. Adjust “FNo.” using the up-down control until it

shows 5.6 and the “TIME” display shows an exe-

cutable shutter speed.

4. Correction

The figure following “5.6” shows the necessary re-

duction of light power or working aperture in

1/10 of f-stops (EV).a"

Word of advice...be sure that when you use spotmetering of any type that your spot chosen is an area in the scene that is representative of a MID-TONE, or else you will have bad exposures because the meter ALWAYS tries to suggest how to render the target area to mid-tone in the scale!!!

xkaes · Sep 27, 2023

wiltw said:
Word of advice...be sure that when you use spotmetering of any type that your spot chosen is an area in the scene that is representative of a MID-TONE, or else you will have bad exposures because the meter ALWAYS tries to suggest how to render the target area to mid-tone in the scale!!!

An often forgotten point in normal photography, but since the OP is just comparing the booster results to the Sony camera results, as long as the two systems read the same thing (which is still a question in my mind), it's OK for the test.

wiltw · Sep 27, 2023

xkaes said:
An often forgotten point in normal photography, but since the OP is just comparing the booster results to the Sony camera results, as long as the two systems read the same thing (which is still a question in my mind), it's OK for the test.

The user instruction which I posted in post 15, instructs to set the meter to f/5.6 ...which implies that one must mentally shift that measurement, in order to use ANY OTHER aperture.

Dazzer123 · Sep 27, 2023

wiltw said:
The instruction for using Sinar Booster 1 with Minolta Autometer IVf

Ah-ha! .......... could you please give me a link to that manual which mentions the Autometer, i can't find it anywhere!?

wiltw · Sep 27, 2023

Dazzer123 said:
Ah-ha! .......... could you please give me a link to that manual which mentions the Autometer, i can't find it anywhere!?

https://manualzz.com/doc/1930705/sinar-booster-1-minolta-flashmeter-iii-minolta-flashmeter-iv

on page 2 of 2... Virtually ALL of the instruction pertinent to Autometer IVF with ambient light was included in my post 15. Setting meter to f/5.6 is identical for the other Minolta meter models, too.

Dazzer123 · Sep 27, 2023

wiltw said:
https://manualzz.com/doc/1930705/sinar-booster-1-minolta-flashmeter-iii-minolta-flashmeter-iv

Thanks!

wiltw said:
The user instruction which I posted in post 15, instructs to set the meter to f/5.6 ...which implies that one must mentally shift that measurement, in order to use ANY OTHER aperture.

I'm not sure i understand (i'm not with the gear right now), could you give me an example?

wiltw · Sep 27, 2023

Dazzer123 said:
Thanks!

I'm not sure i understand (i'm not with the gear right now), could you give me an example?

You change the meter until you see f/5.6 as the aperture, and the meter will tell you what shutter speed matches....although the Minolta meter is shutter speed priority, you simply take the reading and adjust up/down until you see f/5.6

Dazzer123 · Sep 27, 2023

wiltw said:
You change the meter until you see f/5.6 as the aperture, and the meter will tell you what shutter speed matches....although the Minolta meter is shutter speed priority, you simply take the reading and adjust up/down until you see f/5.6

wiltw said:
https://manualzz.com/doc/1930705/sinar-booster-1-minolta-flashmeter-iii-minolta-flashmeter-iv

on page 2 of 2... Virtually ALL of the instruction pertinent to Autometer IVF with ambient light was included in my post 15. Setting meter to f/5.6 is identical for the other Minolta meter models, too.

Right, but i think on the Flash Meter, you set the aperture to 5.6 before you take the reading. That was what i was missing on the Auto Meter and hadn't found the manual for it!

Dazzer123 · Sep 27, 2023

Hopefully on Friday i have have time to repeat this test, armed with this knowledge .......... and will also be more careful with the Sony meter reading ........and will report back!

Thanks again!

xkaes · Sep 27, 2023

wiltw said:
The user instruction which I posted in post 15, instructs to set the meter to f/5.6 ...which implies that one must mentally shift that measurement, in order to use ANY OTHER aperture.

That makes sens, of course. On the Minolta Boosters, they have instructions on how to adjust the booster itself -- you need the booster manual to do that, of course.

xkaes · Sep 27, 2023

Dazzer123 said:
Right, but i think on the Flash Meter, you set the aperture to 5.6 before you take the reading.

Apparently, it depends on the model. On the Minolta Flash Meter II, you dial in the ISO and the shutter speed, and the meter gives you the f-stop. The shutter speed is generally irrelevant, so you are simply reading the amount of light from the flash -- controlled by the f-stop, distance, and filtration.

Comparing Sinar Booster 1 reading to Sony A7 spot reading!

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