The Difficulty in Explaining Equivalence

No, no, no, Don. Sony do not do shift lenses. Its Nikon or Canon.

so what is correct 93 or 9iii or even 9III maybe 9iiv 🤔 ive got it now sony a 9. 20+45-56x67/45 🫣

Yep -- some prefer to be King Shit on Turd Island than a judge in a just court. As wrongdoings in the world go, it really is the smallest of First World Problems in the end. Nevertheless, just one more disappointment that hits close to home. Not to worry -- unrelated bigger disappointments with much more terrible consequences are sure to be made known in short order. 😁

intellegents is inventing contraptions/systems not substanciating inventions.
yesterday my daughter wanted me to print some "Plicker cards" as she is a science teacher. and while i was delivering them to her
my mind reversed engineered what they were used for and how they were designed. wouldnt matter how many computer science/engineering degrees a person has
this was invented by a practical person ,probaly a teacher in the industry with a need. what a great invention, i loved it. i worked as a systems designer for apple back in the 80s.

As we are blindly drifting towards a serious war here in Europe, the antics and ignorance of Mr Caldwell are the least of my worries (yes I read the BS in the DPR thread). I am more worried about one of our dear leaders asking my son to die for Kiev.

I agree it is annoying that a pleasant distraction to daily life has been spoiled.

i was impressed with the Z8 image comparrision on the MF forum. shame the processing was dodgy'ed up to make it look inferior.

😇ignor it unless you seek the true intention 🤔 nobody learns anything by given the answers along with the questions 😊

I could do that as well with my 10x microscope objective (and I could compare full frame and APS-C and 1") but it's not the same thing. That would no longer be testing with 'equivalent' focal lengths for each format, which was the way I did it, so it would illustrate a different principle.

If Mr Gritz does respond to my last message, I think this will be my response. That should close it all off!

LOL, it is admittedly quite funny to watch.

Yes, DPR forum moderation is quite haphazard.

The m4/3 forum seems to deliver a weekly "here's why m4/3 rules the world" post that is full of faulty logic and results in 8 pages of stupidity. TC seems to be getting increasingly grouchy but not with the actual protagonists.

I didn't say your photos were puzzling.

I said they might or might not be dodgy as support for the agenda you push.

I would prefer it to be out in the open too, but as you know the moderator will eject anyone who he perceives is not agreeing that m4/3 is equal or better than FF.

And if you also throw in the fact that a large number of people are viewing images on small screens, the differences are difficult to see.

Thanks, I will have a read of this.

@GreatBustard...

Joe, if I can just side-track the conversation with a question.

In the examples I have used in previous posts (in my debate with the DPR forum member) I use the basic formula to show the physical size of the aperture for a prime lens, e.g. 50mm focal length ÷ f/2.8 = 18mm aperture.

Now... say we have a zoom lens 24-105mm f/4. This means at 24mm the aperture would be 24 ÷ f/4 = 6mm and at 105mm it would be 105 ÷ f/4 = 26mm. Which means that the physical aperture gets wider the further you zoom. Is that right? And therefore total light is higher at longer focal lengths? And DOF more shallow?

When I think of constant aperture zoom lenses like the 24-105 f/4, the assumption I've always made is that the aperture doesn't change at any focal length, but this must only be true in terms of the f-ratio but not true in terms of the actual physical aperture.

Or have I got something wrong here? 😟

Even if the physical aperture doesn't change, something has to change in a constant aperture zoom lens. It might only be an 'apparent' change, but the resulting effects are the same..

In a constant aperture zoom scenario, total light is the same at all focal lengths (aside from things like corner falloff) ... but yes, DOF naturally gets more shallow as the focal length increases..

I just read the ctein article and the comments. OMG. 😂

Why does it seem to be mostly Olympus m4/3 owners who deny equivalence? Is the Olympus marketing that powerful?

OK, so I am not understanding the part about total light being the same at all focal lengths.

Why would it change? The f-number (f/4 in this case) is still the same, and the sensor area is still the same, so total light is still the same, just as if you mounted any prime and shot photos at f/4.

It is as finnan posted:

In short, the effective aperture (entrance pupil) is what's relevant with regards to both DOF and the total amount of light projected on the sensor whereas the relative aperture (f-number) is what's relevant with regards to exposure (the density of light projected on the sensor).

Oh, one more thing: ISO. The ISO setting has little to do with noise except as it indirectly affects the exposure settings on the camera (f-number and exposure time). That is, if you raise the ISO setting from 400 to 1600, then the camera will choose a combination of f-number and/or exposure time that is two stops different, and it is that which results in the greater noise in the photo, not the higher ISO setting, per se. Interestingly, if we keep the exposure the same (e.g. using M mode), then higher ISO settings are less noisy than lower ISO settings, but how much less can vary quite a bit depending on the sensor in the camera and the particular ISO settings used.