Comparing Sinar Booster 1 reading to Sony A7 spot reading!

wiltw

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With the Flashmeter IV, you have the function selector setting for f/number, and you select f/5.6

 
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xkaes

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Anyone know who made the Sinar Booster 1?

I had a Gossen large format film plane probe -- but the meter was permanently attached to the probe -- and it was a standard Gossen meter. This Sinar Booster 1 "attachment"/probe seems like other Minolta meter attachments -- which are not permanently attached..

It may be usable on other Minolta meter -- newer or older -- but who knows? Not me!!! I know it will plug into the Minolta Auto Meter II and the Flash Meter II.......BUT>>>>>>>
 
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Dazzer123

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Thanks folks, all's well that ends well! I re-tested and am now getting consistent results with the Sony, albeit that the Booster 1 / Auto Meter 4F combination consistently tells me a roughly 10-15% longer shutter time compared to the Sony spot meter. Perhaps this is within the normal margin or error / difference for different meters?

Is it normal that you lose some light through the lens compared to a directly reflected measurent. But wait, the Sony is also measuring through the lens! ........hmmmmmm


The box the Booster 1 comes in says Sinar on it, so it seems to be manufactured by Sinar?
 
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Dazzer123

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Sorry, just one other thought on this:

The Sony meter seems to be so consistent, it does make me wonder about the actual benefit of using the Booster 1?

Any thoughts on this? I'm shooting exclusively in a studio environment.
 

xkaes

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That's good news. You will expect a difference between the meters, because both meters are different and both are reading through different lenses. That's OK.

Sinar did not make the booster -- probably Minolta, maybe Gossen, Sekonic.

All you need to do is adjust the reading from the Sony for the Sinar -- no big deal.

The benefit of the Sinar booster is that you can read the exact spot in the scene you want to. Using the Sony to read that exact spot will not be easy.

Sounds like problem solved??????

Lots of shutterbugs use spot meters for their large format shots, or you can use a camera (with spot metering or a LONG lens) to do that. Others use "ground glass meters". No sense in having both -- or all three, unless you need them for others purposes.
 

_T_

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Could your 10-15% difference between the two meters be due to the bellows extension of your camera? I know it’s quite easy to get pretty significant bellows factor when shooting indoors.
 
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Dazzer123

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_T_ said:
Could your 10-15% difference between the two meters be due to the bellows extension of your camera? I know it’s quite easy to get pretty significant bellows factor when shooting indoors.
Click to expand...

Considering i have no clue what bellows factor is, i can only answer: "maybe?"!
(will read up on it)
 

_T_

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The amount of light that hits the film, or in your case the meter, is affected by how far the lens is from the film. The further you extend your bellows to focus the camera on nearby subjects, the less intensity of light your meter will see. Your meter in your sony and your booster should only match up exactly if your camera is focused at infinity, with the minimum possible bellows draw.

There is a formula you can use to calculate the bellows extension factor of your setup. You measure the bellows extension, divide that by the focal length of your lens, square that figure and finally take the log base 2.

log2((Be/f)^2)

That will tell you how many stops of exposure you are losing to your bellows extension.

If you omit the last step, the log2, you get the value of how many times longer the exposure measured by your booster should be than the exposure measured by your sony.

One of the great advantages of a meter like your booster is that it automatically accounts for bellows factor because it's reading is made with the bellows extended. People using other types of meters have to do all that math I just mentioned every time they want to take a picture or else their photos will come out underexposed.
 

Nokton48

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And also if you swing and tilt it can affect your readings, plus the coverage of your lens can be a consideration.. TTL is most accurate way to go.
 

xkaes

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If both lenses are focused at infinity, that "solves" the extension issue -- but the OP is still dealing with two different lenses -- probably not reading the exact same thing -- so a slight difference is to be expected. In addition, the OP is dealing with f-stops, not t-stops. In this instance, that may not be relevant, but thars THREE thangs to mess thangs up.
 

wiltw

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Meters are calibrated to a measurement standard... but the equation contains a Constant whose value is determined by the manufacturer of the meter!...so even 'calibrated' meters of different brands can be about 1/6 EV different!
 
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Dazzer123

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Thanks so much guys, made my first test shot.

(this is just an exposure test, not worried about dust and crap on the scan!):

I used a 1 second exposure at F16 (because i wanted to include the not-very-bright LED strip on the left hand side).


CROP!:

 
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Dazzer123

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Quick question: i'm quite happy with the contrast in this shot.

Do you think it's possible to get the same (or even better) contrast with slide film? If so, which slide films are recommended (and available) at 4x5?

I ask because i read in a few places that slide film suffers from a lack of contrast compared to reversal film.
 
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abruzzi

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well, slide film has--at most--5 stops of range, some have even less. To me thats high contrast, not low. Both of those shots are probably fine on slide film.

Also, to your last sentence--slide film is reversal film. Color negative has less contract than slide film.
 
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Dazzer123

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OK, thanks for that, i guess i'll look for more examples of slide film.

Problem is you never know how much people have pimped the photo in lightroom or Photoshop or if you're looking at the real deal.
 

Nopo

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I think that not being a subscriber, you can not ask directly in the gallery, but it could be a matter of number of posts, if you can not, it will have to be by PM or starting a thread with links to the photos you want information.
I believe that the information obtained will be more objective and realistic than the conclusions you can get on the internet.


Carlos
 

wiltw

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Keep in mind that LIGHTING of your set has a lot to do with the absence or presence of 'more contrast'. Really big apparent size of light source = less contrast.
 
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