Subject | Re: ISO value names are becoming ridiculous |
From | Whisky-dave |
Date | 01/07/2016 12:36 (01/07/2016 03:36) |
Message-ID | <866654e7-4cbc-4948-8100-eba026253556@googlegroups.com> |
Client | |
Newsgroups | rec.photo.digital |
Follows | Sandman |
Followups | nospam (5h & 12m) > Whisky-dave |
Sandmanbut could be a movie file with sound and some camera take a shot and attch a few seconds of audio.
In article <7377ee44-0525-4ed2-a362-5169e49aa8a5@googlegroups.com>, Whisky- dave wrote:SandmanWhisky-daveSandmanWhisky-daveSandmanSo with the D5, it can boost its ISO to ISO 3,280,000, and suddenly how ISO is named is becoming just stupid. We should use EV steps instead:Whisky-dave
SO why start at -1 ?
The base would be what is today called ISO 100, which corresponds to an expected brightness level of the resulting bitmap image.
Why limit it to bitmaps?
Because ISO is film sensitivity and sensor amplification, so it's only a variable for the resulting image.
which might not be a bitmap image BMP.
It's never a BMP and always a bitmap image. It's not going to be a mp3 sound file.
'Your scale' already exists and has done since before yor were born.Whisky-daveSandman
It'sz got nothing to do with sensor amplification eithert.
Yes, it does.SandmanWhisky-daveSandmanSo ISO 50 is one step lower than that, naturally.Whisky-dave
not a 'step' but half I'd say.
No, going from ISO 50 to ISO 100 is one full stop. The scale is arithmetic, remember. Each stop is a doubling of the value. ISO 100 is one stop more sensitive than ISO 50, just as ISO 800 is one stop more sensitive than ISO 400.
yes so, my point was that most cameras you normally set to fixed common ISOs 100, 200, 400, but with DIN the was more choices as thre were with film. you said 50 and 100 like you have to use either of those are you forgetting 64 and 80 ? DIN 19 and 20
I just correctly stated that in my linear scale, ISO 50 would be EV-1 and ISO 100 would be EV 0.
No it isn't but not much more difficult working out anything else that yuo get used to.SandmanWhisky-daveWhisky-daveSandman
I doubt I'd have any trouble working out what 12,800
Which is why it's only a problem now when we have ISO values of 3,200,000 and 4,000,000
but it's not if you just use whats called teh significant bits/number like you have above why is 4 million ISO so complex it's twice as fast as 2 million and half the speed of 8 million ISO or 8M just like we do with semsor sizes and hard disc sizes.
Right, but how many stops faster is ISO 4,000,000 to ISO 51,200? Not so easy to calculate in your head any longer, now is it?
For the answer, ISO 4,000,000 is 6 stops faster than ISO 51,200. Just as ISO 6,400 is six stops faster than ISO 100.but who would need to count stops in this case, it's irrelivent it's not important. It's a relitive number invented by man.
limited in what way ? and I can calculate it in my head even more easily than aperatures, but no calculation is needed you just memeorise it. Tell me how or why you calculate £5.6 lets 4 times the light it than f11. How did you calculate it ? No one calculates it anymore, unless you're learning photography.SandmanWhisky-daveWhisky-daveSandman
would have meant either. which is why DIN or EV would be better than ISO as sensitivities increase as they do today.
Which incidentally, is what I'm saying. In fact, the old arithmetic ASA standard had a logarithmic equivalent later called APEX which is very similar to what I am proposing, where APEX 5° = ASA 100 and APEX 6° = ASA 200 etc etc.
So why change it then, no one really used APEX because there was no reason to.
Since the ISO range was limited and not that easy to calculate in your head.
Mostly it went from ISO 100 up to a whopping ISO 1600. So using an arithmetic scale with those few numbers is easy. When using an arithmetic scale with values from 100 to 4,000,000 it's no longer as easy.Which is why DIN would be better as A it would have less digits B it'd be the same systems as sound. You could also then have a light signal to noise ration in DIN presently with IOS it's virtually impossible to work out.
No it's not. You don't amplifiy the sensor, you amplifiy or in rare cases attenuate the single coming from each 'pixel' on the sensor, that is an analogue value which you convert to a digital value for storing on the card as a numbers which when decoded represent the image taken.SandmanSo any given exposure has an exposure value. Using ISO, you can then amplify the signal by one or more stops to emulate a different EV.Whisky-dave
That's no use though is it as the EV is fixed that's the point. It represents brightness as seen from the sensor or film plane, that's why it's useful.
Hence the use of sensor amplification, i.e. what is called "ISO" these days.