#CROP SENSOR VS FRAME AT 6400 ISO ISO#
#CROP SENSOR VS FRAME AT 6400 ISO SERIES#

I have read about ISO invariance a few times but never took much interest in it because I didn’t see a practical implication for my photography. Tony created a followup video on ISO Invariance that really intrigued me because he demonstrated the effects of “Dual Gain Architecture” used in many modern camera sensors including ones made by Sony. Talk of ISO invariance has been gaining popularity with camera geeks for the past few years and hit the frenzy level a couple of months ago when Tony Northrup made his “ ISO is Fake” video which stirred up a lot of controversy. If you find any of this information useful, please let me know and leave a comment. Maximize the amount of light reaching the sensor by opening the aperture and slowing the shutter, then use a higher ISO if needed to move the histogram. For maximum image quality, always expose to the right (ETTR) when shooting RAW.When shooting handheld in low light, set the aperture as needed, set the shutter to whatever is appropriate to avoid blur based on the focal length (taking advantage of IBIS or lens stabilization), and set the ISO to 400.

In other words, an ISO 1600 image pushed 2 stops has about the same noise as an ISO 6400 image, but the ISO 1600 image will have much better highlight detail. For night and astrophotography using the a6500 (and a6100/a6300/a6400/a6600), ISO 1600 appears to offer the best tradeoff of minimizing noise and artifacting in underexposed images while maintaining dynamic range and highlight detail.***Refer to this article by Thom Hogan for some clues as to why. But when using RawTherapee, the ISO 6400 image was much cleaner***. In my testing using Lightroom or Capture 1, the ISO 400 image pushed +4 stops looked better than the ISO 6400 image.

ISO invariance is somewhat dependent on your choice of raw processor.

This is different than reported at which shows ISO 320 as the second base ISO for the a6500. **Based on testing of my own a6500 camera.

#CROP SENSOR VS FRAME AT 6400 ISO SERIES#

*According to the charts at, the a6600 offers a slight improvement in read noise and a substantial increase in photographic dynamic range than the other a6x00 series cameras. Note that this does not apply to the a6000 which does not have dual gain ISO. The current generation of Sony crop-sensor cameras (a6100, a6300, a6400, a6500, and a6600*) have a primary base ISO at 100 and a secondary base ISO at 400** thanks to implementation of dual gain ISO technology.Noise is not created by using higher ISO, it is created by a lack of light. The tradeoff of increasing ISO in camera is not noise, it is loss of dynamic range and highlight detail.

Crop sensor vs frame at 6400 iso