Which site has the more accurate testing protocol

thanks for the explaination, but i had a play with a friends a7r5 and gave it back after 1 day as the larger pixel count showed no advantage shooting extreme macro, as the stacking programs stack noise into more noise and the a7iv is the only camera i have used that displays no noise at base iso and showed no diffraction, as far as more mpixel cameras displaying more detail that is only true up to iso 320 from there on the a7iv will resolve more detail. this is why no one shows skintone images as test images. the 3 DR charts i posted theres a curve ball in one of the images the pixels are the same size but the sensor is half the size displaying that DR is all about pixel size not sensor size. when i stack 300 images the cleanest single image stacked wins hands down.

Donald, I have no idea what you are talking about. Please stop replying to my posts in this thread.

Hello Arvo, I realize that you are trying to bring some sense into the insane conversation between Donald and myself.

No, I am talking about max possible signal divided by minimum acceptable signal (not SNR) usually expressed as EV. In other words, the "official" definition of DR.

In the same way, perhaps I could make up my own definition of camera sensitivity for example and post it in any discussion involving ISO - but still calling my definition "ISO setting" because that is the equivalent of what Donald is doing. He should not call the result of his method "DR" when it is not. Perhaps "RR" (Recoverable Range) ... 😀

my pentax cameras were the same all around 8 stops, the funny thing is when i process images from my past k100,k10 on modern software shadow recovery is fantastic. back in the day you tested DR actually stopping down the camera and counting the stops of recoverable detail using neutral grey targets, if your shooting 9 stops your at the top level, how cameras are supposidly reaching 15 (eg my a7iv) is beyond provability in my books.

In the Standard, the minimum acceptable signal is the level of luminance at which the SNR is unity i.e. 1.0 or 0 EV. Outside of the Standard, i.e. here, it is whatever Chuck Norris says it is, ho ho.
Yes, I agree that any consistent method is good enough for the purposes of comparison. For example, I often compare texture with Fourier transforms differently to the CPIQ standard www.imatest.com/imaging/cpiq/

Quite so, Arvo. Bill Claff measured my SD9 long ago at 9 and a bit EV.

Diffraction is a "Law of Nature" thing -- no such thing as "shows no diffraction". In fact, for the same DOF, all systems will show the same amount of diffraction (but not necessarily the same resolution, obviously). Usually, macro photography is well stopped down, so diffraction eats into any resolution advantage more smaller pixels have.

If you can show me photos of the same scene with the same settings displayed at the same size, and, if applicable, made by stacking the same number of photos, then we can discuss the matter in a meaningful way. I mean, c'mon, Don -- you remember when you were saying that a compact camera (Olympus XZ-1) was superior to a FF camera (Canon 5D2), right? And you remember the photos you posted to "prove" that point, right? Well, then you'll understand where I'm coming from on this matter. : )

i have a very elaborate micro studio 8 years in the making , im shooting live subjects at 10x FF no crop stacking 300 images for me is a piece of cake using identical live spiders hanging from there web, i can post any number of identical stacked images from the a7r5 and the a7iv. stacking 300 images from a sensor totally trashes everyone's theory that pixel size doesn't increase DR which i find beyond logic 😊 microscope objectives are totally different to a macro lens, they are f4 you cant stop them down. i also make my own equipment which is what pisses alot of people off because i have chosen not to show anyone my set up I invented, and its not electronic but hand machined to my specs. i can stack more detail with my own tube lens design and lighting with a 50yo objective than that of the most expensive mitty objectives. again its all about the light is all im saying get rid of lens flare and a none coated vintage objective obliterates a coated objective 😊 no one can actually question my theories because they cant produce what im doing 😁 when they can they can enter the realm of extreme shooting. you all keep quoting others information instead of actually experimenting and looking outside the box. i had someone last year try to out do what im doing with MF he posted an image he thought was spectacular, so i posted the same subject and oops maybe i shouldn't of 😁

always like a challenge

One of the biggest hurdles that you are facing is that the image you are showing really do not have a high dynamic range, most can easily fit within the standard 8 bit jpg.
Until you start using the term DR in the context that 99% of the photographing community use it. With your images the last several stops of DR the camera is able to record is being clipped by the container you are placing them in so there is clearly not a DR problem.

Until this is resolved I feel that we will be going around in circles just as we have done in the past

dprevived.com/t/iso-dynamic-range-what-is-going-on/7370/post/104469/

DR has nothing to do with 8 bit 10 bit or 14 bit. 12 volt is the same as 12.00000000000000 volt unless you can show me it isnt 🤔 any image can be made to have 15 stops of DR in post 🤔 or is it only 8 to 9 🤔

Everyone will go around in circles until he gets off his tangent. But I'm not sure that will happen anytime soon...

Piece of cake, Donald ...

"12-Volt" is a NOMINAL voltage rating which for a lead-acid car battery can be anywhere between about 11 V and about 16 V in practice, stupid decimals or not, and for a lithium-ion battery will be something completely different a la Monty Python ....

Equivalence at its best. Just for you GB now tell me that the canon shot was better than a point and shoot 🤣 notice the 300% crop the canon couldnt even AF accurately, but it was the same in the twin studios as well that i shot side by side with my k7, the K7 destroyed it. looking back 13 years ago the gear was crap compared to now, auto focus was so bad revisiting some old pro shoots. canon colors were so off "red" tint compared to sony sensors.

One way to compare the texture of these two photos is in the frequency domain via Fast Fourier transformation (FFT). The middle of the images below is zero frequency ... each edge is Nyquist (0.5 cycles per pixel) the maximum possible frequency without aliasing. Each dot is a textural frequency between zero and Nyquist frequency - transformed by ImageJ aka Fiji.

Left (Canon 5D)

Right (Olympus XZ-1)

The smaller the blob in the middle, the less the texture. The Olympus has more texture than the Canon (more dots going outward from the middle) but neither of them is any good really. The horizontal and vertical fan-shapes are probably the exif text.

XpatUSA (Ted Cousins)

thanks for that Ted. very interesting. how i ended up taking the images. i was working for a studio and asked to shoot along side another pro photog for a school graduation shoot. the other photographer handed me the 5dmk2 to take some images while she was organizing the group on stage. so all i had to do was press the shutter. i wasnt sure how good IBIS was on the canon so i held it on top of a ledge and took some shots. i always wanted to know how the oly xz1 was in low light so a raced downstairs and grabbed it from my bag and snapped some shots off for a comparison. it was a great little camera and i always had it with me just incase my pentax K7 broke down, in fact i was on a shoot one time and actually used the oly xz1 because of the focal length and sold several images to a client along side the K7. to this day you couldnt tell the difference in image qual;ity.

Again all of the images that you are trying to show use that have a DR limit are not images that contain more DR that can fit into the standard jpg image contianer.
If all the DR of your image can be contained within then it has to be not an issue of DR degrading the quality of the image.
You have done the very same thing in these post not understanding what DR is.
dprevived.com/t/iso-dynamic-range-what-is-going-on/7370/post/104292/
In this post and the other your images do not contain a large DR so there is no need to have a container larger than what a standard jpg output.

And again I will ask you if you are not anywhere near the bottom limit of the cameras DR as it can not be shown in the limited DR of the format you are trying to show us how can this be an issue.
It is no different than filling a 5 gallon bucket to the top, then preceding to pour all of that 5 gallon bucket into a 1 gallon bucket, then preceding to tell us see that the 1 gallon bucket has the capacity of a 5 gallon bucket.

Well, no you cannot, you can compress 15 stops of DR into the container as it will no longer contain 15 stops of DR in the displayed image.
Again you can not show 5 gallons when it is placed into a 1 gallon bucket.

The good old bucket analogy never fails, unlike an air tank analogy where what goes in comes out with just a tiny energy loss. Scuba divers love it.

The JPEG "container" does have a variable bucket-size, though. One such variable can contain a full-size RGB, not Y'CbCr. But still, the conversion from say 16-bit TIFF to such a JPEG might still lose some "DR" however that is defined. In other words: "does re-sampling any image affect it's DR" ?

Leading us back to what is the DR of an image and what is the formula thereof?

"Wot,no formula?" (English 1940s Chad graffiti from WW II rationing)

xpatUSA (Ted Cousins)