Crop Lenses on Crop Bodies: How It Works vs Full Frame (APS-C & M43)

Covering some myths and misconceptions about how lenses designed for smaller sensors work & the pros and cons of using full frame glass on crop bodies.
👍 Thanks for watching! Please like, comment, & subscribe.

=============================
Gear I Use to Make Videos:
=============================

=============================
Music:
=============================

=============================
Follow Me:
=============================

=============================
Affiliate Links:
=============================
Some of the links in my video descriptions are affiliate links, which means at no extra cost to you, I will make a small commission if you click them and make a qualifying purchase. If you have a different purchase in mind, you can also use these storewide links below.

=============================
#cropfactor #apsc #microfourthirds

[guymross]

It's amazing that Gerald is basically the only living human person capable of explaining basic photography and videography concepts. Thank you Gerald.

[dajael]

My Man, you somehow got about an hour's worth of information into that 09:23 window. I don't know exactly how you did it but you did! I'm gonna go watch it again and maybe even a 3rd time if necessary ;-) Great job!

[ShaayarAajnabee]

OMG.. yessss!. You answered the questions I had in my mind. I felt like generic boxed illustrations were misleading on internet when they compared the APS-C body with full frame lens and vice versa. But never got a good explanation of focal length and field of view of APS-C body with APS-C lenses. You explanation is perfect.
Although I been into photography since last year, bought a dslr myself, used it, and have watched lots and lots of tutorial videos, camera reviewers, etc on youtube. However, I just stumbled upon your channel few days ago and I have learned so much from watching your videos over the last few days. Your videos are loaded with detailed information. There is no unnecessary long b-roll intro. There is no time wasting. You get right to the point and sum it up just enough in such short time. I can't thank you enough. Usually with other reviewers and videos I end up skipping and fast forwarding. But with your videos, there is no space to skip forward because every second is to the point and important. In fact, I have to replay certain things just to wrap my mind around it. I like how you cover so much in short time. I can't thank you enough. Please keep making videos like this. If anyone needs legit answers about photo/videography I will be directing them to your channel. Subscribed!

[DesertCookie]

The amount of people I've recommended this to on Reddit to clear up their confusion is... at least four.
Phantastic explanation. I come back to it now and then to make sure I don't get mixed up with my terminology.

[FastEddie]

This a fantastic explanation without a lot of technical facts. It was perfect for for someone to understand the different sensor sizes. Thanks!

[Dave_Stafford]

You've a real talent for taking this tech stuff by the scruff of the neck and knocking the complicated out of it.. love these, ..educated and entertained. Thanks!

[romariop]

Too many youtube videos are confusing people about the crop factor always mentioning it even with apsc lenses designed for apsc cameras
Im glad i found your video to clear what mixed up knowledge i had before

[pablopugliese]

I am so glad that you are bringing real optics talk into youtube, every video I see from you surprises me even more. Your explanations and how you organize your content is absolutely amazing! You get to the core of things, where science becomes accessible for practical application.

[geraldbertram]

By far one of the best explanations of this subject I have seen yet. Well done, Gerald. By the way, you have an AWESOME name

[gmolina]

If you can't explain something with simple words, then you don't really understand it yourself.
I already knew everything you said, but I watched anyways. You've done an outstanding job explaining this subject. I will refer this video when people ask me about this topic.
You just gained a subscriber and I hit the like button thrice ! Cheers!

[danipphoto]

This video was INSANELY helpful. I appreciated the visuals and illustrations more than you know, I recently discovered that I may have ADHD so I need this kind of content, I struggle to just listen to people talking! I have never come away from a video without questions before. Thank you so much!!

[PeterMKent]

Great effects and very entertaining, I almost didn't watch this one but really enjoyed the explination.

My issue with "crop factor" has always been its reliance on first understanding a lens' FoV on another body.

Again if everyone started naming sensors by their diagonal measurement we would have far less confusion, because a lens that measures the same as the sensor's diagonal provides a neutral "Field of View".

That's a 43mm on a "Full Frame", 28mm on an APSc and 21mm on a Micro FourThirds.
If you want a Telephoto you would multiply by 2; which is 86mm on FF, 56mm on APSc and 42mm on mFT.
A wide angle would simply be divided by 2 so a 21.5mm on FF, 14mm on APSc and 10.5mm on mFT.

[tremaincheerful]

Your explanation is the clearest most concise and logical I have ever found on this issue. Your flashlight illustration perfectly explains why we do not see sharper edges in our photos when using FF lenses on crop sensor bodies. The light focused by the lens is diffused over a larger area, more of the detail the lens is able to focus is wasted outside the sensor area. This is born out by rigorous tests by DSO mark, as referenced in Tony Northrup's excellent video on this subject. "Perceived" megapixels will be less when using FF lenses on crop bodies, particularly if they are poor lenses to begin with.

[RenatDavodov]

When someone (like me) want's to learn how things ACTUALLY work and not just the basics, your work is golden. Thank you a lot.

[blueckaym]

at 7:35 starts the correct explanation!
A Xmm focal length lens is such regardless of being designed for Crop or FF. The cropped lens only have different design so that they save some glass, since there's no need to cover bigger projection.
Same goes for F-stop f/1.8 in crop-lens is exactly the same as f/1.8 in full-frame lens - as it's simply the ratio between the aperture & the focal-length, and since focal-length is the same then the aperture is the same at given f-stop. Ie it produces the same depth of field (or bokeh) (ignoring the actual quality of image and T-stop).
The only difference is the size of the projection and the size that you can capture from this same projection - ie the sensor size.
The flash-light example at 5:12 is extremely misleading! It can easily fool you to think that crop-lenses for same given focal length have some kind of speed-booster inside them, which they don't.

[michaels]

Gerald Undone is killing it with some down those who keep trying to befuddle, confuse, and mislead the public...

[dunnadidit]

Great video dude! My favorite thing to see in the comments is when people say you have to crop the aperture number too... I mean I get where they're coming from but it's not technically right.

[its_arunprakash]

I don’t know why schools won’t teach this subject of optics which is so much important in real time..
Well done.. and thank you for bursting misconceptions..✌🏻✌🏻

[Quarmacy]

Thank you so much. I was so confused by my own research. Now I can rest easy using my 50mm full frame lens on my APSC camera.

[lucykaleisky]

the answer of my question. Thx Gerald. Short and clear as usual (two years later x) )