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Author Topic: Base/Optimal ISO setting for Sinar eMotion75?  (Read 1803 times)

lowep

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Base/Optimal ISO setting for Sinar eMotion75?
« on: December 21, 2011, 11:12:21 am »

What is the optimal iso setting the original Sinar eMotion75 was designed for?

Unsure if optimal is the right word or not. Maybe start/base/native/floor...  ???

Whatever the word, am I right to assume that exposing at the particular "iso" an MFDB is designed for will give cleanest files with least noise, and if the answer happens to be 200 iso rather than 100 iso then exposing at 100 iso will not give any improvement in terms of IQ than exposing at 200 iso, whereas exposing at 400 iso and 800 iso will be noisier than optimal iso due to increased amplification of the signal recorded by the sensor?
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henrikfoto

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Re: Base/Optimal ISO setting for Sinar eMotion75?
« Reply #1 on: December 21, 2011, 12:42:35 pm »

All the Sinarbacks are very much better at iso 50. I think anything above iso 100 is useless if you ask me.

Henrik
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baudolino

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Re: Base/Optimal ISO setting for Sinar eMotion75?
« Reply #2 on: December 21, 2011, 01:02:20 pm »

The Sinar eMotion 75LV which I used to have had its base ISO 100. I understand mine was the latest version, with a slightly larger display. I believe the older versions had a smaller display and a base ISO of 50. From my experience, images shot at ISO 400 with my latest version back were entirely usable, especially in print, as long as they were not underexposed. But of course, this back (like all MFDBs) excels in situations with plenty of light and when shot at base ISO.
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Lacunapratum

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Re: Base/Optimal ISO setting for Sinar eMotion75?
« Reply #3 on: December 21, 2011, 01:08:37 pm »

100 ASA for mine, also late version.  200 ASA still usable, but less so. 
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henrikfoto

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Re: Base/Optimal ISO setting for Sinar eMotion75?
« Reply #4 on: December 21, 2011, 01:32:00 pm »

I think if you go higher than 200 a normal Canon or Nikon will do a much better job.
I had the back too, but never was happy with any shot above 100...

Henrik
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lowep

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Re: Base/Optimal ISO setting for Sinar eMotion75?
« Reply #5 on: December 21, 2011, 02:39:38 pm »

Henrik you write "all the Sinarbacks are very much better at iso 50" however the lowest iso setting on my eMotion75 is 100 so maybe I am missing something?

Looking into this further I found this information in a post by Thierry Hagenauer in this old thread that confuses me even more:

Try the eMotion at ISO 100 and try another back from another brand at ISO 100. Compare the images and the histogram. Most probably you will see that the eMotion is 1 stop brighter than the other back, or that you have to switch the other back to ISO 200 to get the same exposure/density. Or in other words, "our" ISO 100 is equivalent to ISO 200 from another back.

So does this mean digital iso is not standardised as film iso, and also that:

1) digital iso setting (eg on a MFDB) may represent a different exposure value than film iso (ie "correct" exposure at 100iso according to a reading from an old light meter may not be right for a MFDB set at 100 iso)?

2) doubling digital iso does not necessarily double the amount of light as doubling film iso (ie double the iso = exact same effect on exposure as opening up 1 f-stop or halving shutter speed),

3) lower digital iso does not necessarily translate into better IQ (since some MFDBs have a base iso of 200 while others have a base iso of 50 0r 100 asa)?

Obviously I don't know and please correct if I am wrong but all this makes me want to know even more the actual "optimal" iso setting for the eMotion75 as it seems like digital iso depends on whatever any manufacturer decides is best rather than any international standard.

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TH_Alpa

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Re: Base/Optimal ISO setting for Sinar eMotion75?
« Reply #6 on: December 21, 2011, 02:41:17 pm »

FYI:

The nominal ISO for the eMotion 75 or 75 LV is ISO 100. There was effectively an earlier version with nominal ISO 50.

Sinarback eMotion 75 LV

Concerning the use at high ISO, have a look at this old thread on another forum, some samples I've shot to show what is possible at ISO 800 with the eMotion 75

ISO 800 - some Sinar eMotion 75 samples

Best regards
Thierry
« Last Edit: December 21, 2011, 03:01:58 pm by TH_Alpa »
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lowep

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Re: Base/Optimal ISO setting for Sinar eMotion75?
« Reply #7 on: December 21, 2011, 02:56:09 pm »

Thanks Thierry that answers that.

I also get "useable" results at 800iso for A4-size prints, ok results at 400iso and at 100 iso superb results in terms of IQ even at 100% from this legacy back.

As Neil Young sung rust never sleeps.
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TH_Alpa

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Re: Base/Optimal ISO setting for Sinar eMotion75?
« Reply #8 on: December 21, 2011, 03:01:08 pm »

Henrik you write "all the Sinarbacks are very much better at iso 50" however the lowest iso setting on my eMotion75 is 100 so maybe I am missing something?
Please read my information just posted after yours

Looking into this further I found this information in a post by Thierry Hagenauer in this old thread that confuses me even more:

Try the eMotion at ISO 100 and try another back from another brand at ISO 100. Compare the images and the histogram. Most probably you will see that the eMotion is 1 stop brighter than the other back, or that you have to switch the other back to ISO 200 to get the same exposure/density. Or in other words, "our" ISO 100 is equivalent to ISO 200 from another back.

So does this mean digital iso is not standardised as film iso, and also that:

1) digital iso setting (eg on a MFDB) may represent a different exposure value than film iso (ie "correct" exposure at 100iso according to a reading from an old light meter may not be right for a MFDB set at 100 iso)?
That was the case at the time. There was effectively no standard for ISOs and how it is calculated. I can't say for now and how this has evolved, but I doubt there is any today.

2) doubling digital iso does not necessarily double the amount of light as doubling film iso (ie double the iso = exact same effect on exposure as opening up 1 f-stop or halving shutter speed),
Correct, in the case of the Sinarbacks it was in fact an under-exposure of the amount of push (e.g. ISO 800 was an under-exposure of 3 f-stops from the nominal ISO 100). But not all brands did or do handle "higher as nominal" ISOs the same way.

3) lower digital iso does not necessarily translate into better IQ (since some MFDBs have a base iso of 200 while others have a base iso of 50 0r 100 asa)?

Obviously I don't know and please correct if I am wrong but all this makes me want to know even more the actual "optimal" iso setting for the eMotion75 as it seems like digital iso depends on whatever any manufacturer decides is best rather than any international standard.
Use it at ISO 100 for best results.

Best regards
Thierry
« Last Edit: December 21, 2011, 03:07:39 pm by TH_Alpa »
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lowep

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Re: Base/Optimal ISO setting for Sinar eMotion75?
« Reply #9 on: December 21, 2011, 03:23:16 pm »

Use it at ISO 100

Good to be able to do so with confidence that it is correct rather than guesstimate, one less loose cannon on the rolling deck  :)
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