[mikesbike]

I just confirmed tv viewing distance is based on screen size x1-2. It's not based on the equivalent distance of 50-100 of a 50 tv. But now I have done the math and know that for a 32unit tv the full50 frame viewing distance of 50-100 equivalence is 32-64 units.
Seriously what's the real difference that makes this silly and the other not?

The imagined analogy is silly, because we are not dealing with stretching and contracting TV sets at various distances.

We are dealing with cameras with specific sensor sizes that present a distinct angle of view to the user when using specific lens focal lengths. If the user never has any use of any other format, there is no need to offer any equivalent information, unless someone asks for the information regarding the difference when using one format compared to another with a lens of a given focal length, which is the basis of this thread.

Unlike the imaginary TV sets and distances, all one has to do is look through the camera's viewfinder to verify the difference, and shoot an image at a given distance to see the result. This is how you use it, and this is what you get with each camera's format size. These differences come up because the two format sizes involved here are very commonly used by those interested in DSLR cameras.

---------- Post added 04-23-19 at 04:41 PM ----------

Cheers guys, this is all very helpful. Appreciate all the background insight as well!
Bottom line for me, will try and go for DA*200mm rather than 300mm if there is a good one to be found.

Ondrej

Both are very fine choices, I have both. The DA* 200mm is a very fine choice, especially since it offers f/2.8 aperture capability. And yes, if you should get a K-1 FF body, it is fully usable on it as well. You can also add a 1.4x TC and get nearly the same FL as the 300mm and about the same aperture, but in a less weighty ensemble.

I will say, however, its SDM AF is not as fast on my cameras as my non-SDM screw-driven FA* 300mm f/4.5 lens.

[swanlefitte]

, Do not answer, as nothing you have actually offered disputes the facts I have given, it's weird how much you have said against me, whilst agreeing with every fact I gave.
I believe, any reply from you would fall into your class of redundant.

Didn't see anything said against you by me. As you point out I didn't dispute you .

[swanlefitte]

The imagined analogy is silly, because we are not dealing with stretching and contracting TV sets at various distances.

.

We are stretching and contracting field of view. (X)sensor is universal in that and not limited to a sensor size most don't use. Let's work with everybody not just 35mm film and 35mm film sized sensor users.

[UncleVanya]

We are stretching and contracting field of view. (X)sensor is universal in that and not limited to a sensor size most don't use. Let's work with everybody not just 35mm film and 35mm film sized sensor users.

X sensor doesn't help most people who don't think in geometric terms. The only time I use ff equivalence is when dealing with someone with 35mm film experience or apcs and full frame cameras. I have used m43 as the standard in discussion with an m43 shooter about APSC. (x) Sensor adds a layer of confusion to most discussions. I am happy to try it but knowing the math phobia of many I think it will be a lead balloon.

[swanlefitte]

X sensor doesn't help most people who don't think in geometric terms. The only time I use ff equivalence is when dealing with someone with 35mm film experience or apcs and full frame cameras. I have used m43 as the standard in discussion with an m43 shooter about APSC. (x) Sensor adds a layer of confusion to most discussions. I am happy to try it but knowing the math phobia of many I think it will be a lead balloon.

I certainly appreciate that the math might confuse as much as the math does already. It appears you do the math for m43 users. Yet the math of ratios is inherent in photography. as related to sensor alone we have wide angle, normal, telephoto and macro, knowing pixel pitch too, and then we have telephoto converters, fstop, EV, keep going... binoculars, microscopes, telescopes all use (x)times as do zoom lenses. Everytime you can relate to this relation you are reinforcing your understanding of photography across the board.
If we need a universal equivalence to something why not 1inch sensor? ( I don't get 1 inch sensor except marketing, not metric? come on) I am sure everyone would say that this was silly. In fact if my 1inch sensor camera said it had a 4x zoom a question a confused person might ask is what lens is 4x on an apsc? If the 1inch sensor camera says the lens is 200mm FF equivalent instead then the confused person asks what is a 200mm FF lens for apsc and if its a dx is it 200mm and if its fx will it be a 300mm? and if its a 300m then will it be equivalent to a 450mm on apsc and why can my small cameras lens with the 1inch sensor have a 200mm lens so small? etc.

I hope that clears up some of my points.

[mikesbike]

We are stretching and contracting field of view. (X)sensor is universal in that and not limited to a sensor size most don't use. Let's work with everybody not just 35mm film and 35mm film sized sensor users.

I believe this thread is talking about the difference between APS-C and 35mm / FF format use. The interest expressed was specifically as to the difference in FOV at the same distance with the same lens. Therefore, no need to "work with everybody" having a variety of sensor sizes, unless the desire is to make something uncomplicated into unrelated complicated banter.

If there is no use or usage contemplated, other than any one given sensor size, again there is no need to discuss equivalency.

[swanlefitte]

here is the OP's question from the rephrased second post.

In other words, when I take DA*300mm (which I undestand to be apsc designated lens) and put it on K3, will I see photos that actually are same as if I took K1 with a full frame 300mm lens or will I see photos that are equivalent to K1 + 450mm full frame lens?

The answer is no, there are two ratios involved here. First the ratio involved in ff compatable vs apsc compatible is the ratio of sensor that the lens projects the scene on. If the entire scene is projected onto the given sensor it is deemed compatable. The second ratio is that of the sensor width vs the lens length which determines the field of view. any 200mm lens on a given sensor will have a specific ratio to that size sensor.

This also clears up this part of the op's inquiry. "I also understand that if I take for instance DFA 100mm macro lens and mount it on my K3, the pictures it takes would be same as with using a 150mm apsc designated lens."

Notice this was after already getting 2 versions of the standard answer.

[UncleVanya]

here is the OP's question from the rephrased second post.

The answer is no, there are two ratios involved here. First the ratio involved in ff compatable vs apsc compatible is the ratio of sensor that the lens projects the scene on. If the entire scene is projected onto the given sensor it is deemed compatable. The second ratio is that of the sensor width vs the lens length which determines the field of view. any 200mm lens on a given sensor will have a specific ratio to that size sensor.

This also clears up this part of the op's inquiry. "I also understand that if I take for instance DFA 100mm macro lens and mount it on my K3, the pictures it takes would be same as with using a 150mm apsc designated lens."

Notice this was after already getting 2 versions of the standard answer.

I literally have no idea what you are trying to say.

[swanlefitte]

I literally have no idea what you are trying to say.

That makes sense. The quote vanished I was referencing. Sorry don't know why but I had it there from op' s second post.

[dbs]

Hi oh 9000

You have the DA300 just use it on your camera and runaround or crop during post processing and not worry about anything else.
Just enjoy the photos you take and be happy...........
Or just buy more lenses.....a expensive rabbit hole that one


Dave

[oh_9000]

Hi oh 9000

You have the DA300 just use it on your camera and runaround or crop during post processing and not worry about anything else.
Just enjoy the photos you take and be happy...........
Or just buy more lenses.....a expensive rabbit hole that one


Dave

Hi Dave

Love the be happy suggestion, cheers mate

[Ajax156]

But what is the 'equivalent' level of pissed my wife will be if I buy another lens to get the 'equivalent' results in my crappy photos, that she has the 'equivalent' level of interest in, that I have in her accounting spreadsheets??

<poor humour>