I hope that covers everything you wanted to know, (or didn't know you wanted to know). If you still happen to have any questions, feel free to ask them here!

See something on any show that you want to buy?
Head on over to https://kit.com/PhotoJoseph

•• Panasonic Lumix 14mm f/2.5 ••
http://geni.us/BcC3yne

•• Canon EF 14mm f/2.8L II USM Lens ••
http://geni.us/P2Ed

A simpler explanation of the focal distance is that you can approximate a lens with a simple convex lens (like a magnifying glass). The focal length is the same as the focal length of the simple lens that behaves the same way i.e. it is the distance between its center and the sensor.

In practice lenses are more complex so that they can correct distortions and also for practical reasons like the mirror mechanism of a DSLR that prevents anything close to the sensor.

Thanks Photo Joeseph! My question is does a 25mm mft lens that has a 50mm equivalent field of view have similar compression effect that a full frame 50mm has?

Very well done, dude. Extremely succinct visual explanation of something that is a bit confusing and un-intuitive.

It just gets more confusing the more I watch different videos. Why not just show what the equivalent lens for MFT would be to that 14mm full frame image? To capture this exact field of view [...+...] you use "this" lens on MFT cameras. I think that would make me say... ohhhhhhh....... and I'd figure out everything else from that answer. But I get it, the question here is to show that the size of the things in the image is the same but MFT sensor size limits what it captures.

My question was how do I get "all" of that field of view on the MFT sensor? I am sure you could just change the physical distance between the camera and the subject as well. But maybe that is really far away therefore you may loose some resolution. Since MFTs have a 2x crop factor (which means the sensor is 1/2 the size of full frame) you divide 14mm by 2 and that's the lens you would need which would be 7mm. It would capture the same ratio of data without moving farther away from the subject. Is that incorrect? my head is spinning lol. I guess the main question I had was to figure out if I really need to get a 35mm lens for my MFT to shoot in 35mm? But if this theory is correct, that 35mm lens may capture at a zoomed perspective in relation to ratio between sensors therefore the images at a 2x zoomed (MFT) sort of "field of view" then might as well be considered a 70mm lens for a full frame. If that's true I guess the only concern is being mindful of using a 2x cropped sensor and trying to get the image ratio equivalent to 35mm full frame by changing the distance between the camera and the subject as least as possible.

Then the question is about dynamic range and quality if we are trying to get a full frame image sized into a MFT. Would a concern be loosing data quality, vignetting or fish-eying? Not to jump back into ignorance but would it then make more sense to have a higher megapixel camera? Hmmmm...?

Thanks for that demonstration comparing the size of images caught between both lenses and how they are virtually the same size. That helped answer a lot of questions...

Fantastic explanation 👍🏾

wow !! U have taken so much pain to make this video and explain it from a dummies point of view going really basic.. Thank You sir

Great explanation and examples, thank you

Nice video. One of the few video's that makes it clear that crop cameras don't change the focal length. For those interested in crop vs full frame test look in YouTube for "Pentax K1 Full Frame vs Crop modes Test"

my mind was blown when you talked about the definition of a telephoto lens

Hi PhotoJoseph

To get same size photo with aps-c sensor as in 50 mm lens with full frame camera , we need to take ~35mm apps-c lens

Which lens would you consider to be the best overall for the GH5 in a studio setup with two people talking in front of it plus occasional product reviews?

Nicely done!

Hi Joseph, regarding the gh5, when attaching a manual lens to a gh5 the camera asks for the focal length to be chosen, my understanding is this is for the stabilisation to work correctly with that focal length, correct? If so, what would you need to select as the focal length of say a Helios 58-2 with a .71 speedbooster as an adapter? The effective focal length of the Helios without the speedbooster is 116mm on the gh5 but is 82mm with the speedbooster, so do I choose 58,116 or 82? Thanks, apologies if there is an error in calculations

So what do we think will happen to Panasonic's 4/3 line up after they release their full frame.
Will they slow down development for 4/3rds and go all in for full frame, or can both systems get equal support?

THANK YOU!!!!
So g-d tired of listening to "YouTube experts" ( cough, pretty boy and pretty wife, you-know-who, cough) giving these long explanations that throw BASIC OPTICS and PHYSICS out the door!?!?! 😣
This was the most simple and realistic point about: field-of-view and ability to capture data in a digital camera.
Yes the marketing has become the "alternative facts" to how a lens and sensor work.
Just stop the madness. 🙄🤓😎

Amazing explanation. Keep all of this up, in this sort of detail. Onwards to 100k Subscribers!

Good explanation. But what I think is needed is a follow up video on a more practical issue - how does this affect aperture and iso at identical shutter speeds when using different sized sensored cameras.

The best explenation sensor size in yt, realy:) from A to Z!!!

Great explanation Joseph! Thank you for that!