DPReview.com is closing April 10th - Find out more

The Fujifilm X-H2 High ISO Noise vs the X-T2

Started 2 months ago | Discussions thread
Truman Prevatt
Truman Prevatt Forum Pro • Posts: 14,596
Re: The Fujifilm X-H2 High ISO Noise vs the X-T2
1

It's read noise. In today's CMOS sensors, the limiting factor is photon shot noise.  If the read noise were zero - it would not matter much.  The most important criteria is the photon flux (photons/pixel/second) . Translate that to exposure.  As this number goes to zero - the sensor out put will be sampled thermal (read) noise.  That is if we put on a light proof lens cap on and take images, we will still get electrons sampled - that's the read noise.  Until the photon flux produces sufficient photons - the read noise will dominate the photon noise.  After that the shot noise is the limiting factor in SNR.  Today most CMOS sensors are shot noise limited in most situations.  Astro photography could be the counter example and in those applications specialized cameras are usually used.  Such cameras may use a CCD imager or a cooled CMOS or cool CCD in extreme cases.

The most critical roll in determining noise is the photon flux. In reality all comparisons should be scaled to a standard photon flux to make a valid comparison.  That is a common area on the sensor.  The XT2's pixel is larger than the XT5 pixel.  For the same light energy, more photons per second are incident on the XT2 pixel than the XT5's.  There very few discussions you see that addressed in.

However, more the most part 99.99% of most images are taken in the photo shot noise limited region.

-- hide signature --

"The winds of heaven is that which blows between a horse's ears," Bedouin Proverb
__
Truman
www.tprevattimages.com

 Truman Prevatt's gear list:Truman Prevatt's gear list
Leica Q2 Monochrom Fujifilm X-H1 Fujifilm X-Pro3 Fujifilm XF 35mm F1.4 R Fujifilm XF 50-140mm F2.8 +12 more
Post (hide subjects) Posted by
(unknown member)
JNR
JNR
JNR
JNR
JNR
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow