AlohaBob Loc: Los Angeles, CA

My A77 has ISO to 50. I have searched, but not been able to find out whether this is the native ISO or an extended ISO. Does anyone know? I use a fast lens and can usually use ISO 50, but have read that in some cases it's better to go with the Native ISO even if it's higher.

lightcatcher Loc: Farmington, NM (4 corners)

This may help... http://www.slrlounge.com/school/reasons-why-you-should-shoot-hdr-images-at-the-lowest-native-iso-setting/

AlohaBob Loc: Los Angeles, CA

Thanks for the answer. I think that article is what got me wondering about this and trying to find out if ISO 50 on the A77 was extended or not.

Carl 383 Loc: Southampton UK

The native ISO is 100.
However there is very little difference and you would really have to do some extreme pixel peeping to see the results.

A very satisfied A77 owner.

CHOLLY Loc: THE FLORIDA PANHANDLE!

Bob, it IS a native ISO in that you can set your camera to 50 ISO... but you can not use ISO 50 for either the Auto ISO function OR the Multi-frame Noise Reduction function.

The normal (native) ISO range of the camera is 50-16,000. Auto (and MFNR) ISO range is 100-25600.

Let me suggest the following resource to you... that is, if you don't already have it:

http://friedmanarchives.com/alpha77/index.htm

This is THE best book available for your camera. It is EXCELLENT in every respect.

Friedman covers each and every feature of the A77 in great and complete detail, but writes in plain, easy to understand English.

He explains each function and tells you when, how, and why to use them.

Best of all, he gives you a 2 week money back guarantee. :D

This book is worth much more than what he is asking, and would be a steal at twice the price. :thumbup:

AlohaBob Loc: Los Angeles, CA

Hi Cholly, thanks for the book recommendation. I'm downloading now. Looks very good. I have Busch's book but have found it more frustrating than useful; to be fair the data is there, it's just hard to find and doesn't do a great job of evaluating what's useful and what's not.

Peekayoh Loc: UK

I would suggest that you use "base iso" rather than "native iso" for this condition. Neither expression is a standardized term (leading to confusion) but ...
- "base ISO"; is the lowest "true" ISO setting we can choose in our cameras.
- "native ISO"; is most often related to raw sensor data after basic demosaicing, curve and colour transforms (and is lower than "base ISO")

The a77 baseISO is 100 and so, the manual says, "The recordable range of the brightness of a subject (dynamic range) is slightly narrower for areas where ISO is less than 100." The reason for that is overexposure that can somewhat blow the highlights.

Expanded lowISO values are nothing more than overexposed images that sacrifice something on the highlight side and with a bit of knowledge and reliable raw converter, shooting at "normal" ISO values should give at least the same results as shooting using "expanded" ISO values (low and high) without sacrificing loss in raw data as is the case with highlights when using low expanded ISO values.

Having said that, iso50 can be a convenience for certain scenarios and certain users and the difference in IQ at these low ISOs will have only a marginal difference on the finished image.

planepics Loc: St. Louis burbs, but originally Chicago burbs

I was unable to copy it (Adobe acrobats manual download wouldn't allow) BUT on pg 139 of your manual (I have the same camera) it tells how you can tell the camera what range of ISO sensitivities you can set the camera's auto selection for.

AlohaBob Loc: Los Angeles, CA

Thanks for the clarification of terms. Correct definitions are vital for clear communication. Much appreciated and thanks for reference to the manual. I had looked there and either didn't see it or it went over my head, but makes perfect sense. I've found myself using ISO 50 outdoors so I wouldn't have to stop down so far.

AlohaBob Loc: Los Angeles, CA

Thanks! This is a great tip. I wanted to use auto ISO, but didn't like the ranges and had read somewhere it couldn't be set.