BebuLamar

OK! I meant any distance you can focus with the lens alone. That is why we are talking about a micro lens otherwise any lens can focus close with extension. Also when using extension to achieve focus internal focusing become irrelevant.

cbtsam Loc: Monkton, MD

Did you intend to say "Uh?" or "Huh?" Not trying to start an argument, just seeking clarification.

Silverrails

My understanding of the "Crop-Factor" with a Nikon APS-C model Camera is that your actual view thru the Lens, so if you are using a 50mm lens on a APS-C Camera, you must multiply 50mm x 1.5 = 75mm new Field of View thru the Lens. Also this affects the defined D.O.F.= Depth of Field too.
This is created by the Crop-Sensor ASP-C Nikon Camera having a smaller Sensor size, than a FULL-FRAME CAMERA, changing the actual Field of View of the 50mm lens, but physically it is still only a 50mm lens, the smaller sensor multiplies the percepted or Precieved F.O.V. from 50mm to 75mm.
Now, if my understood description of this mathmatical formula is incorrect, PLEASE Correct my understanding, but this is the way I understand the "CROP-FACTOR on a CROP-SENSOR DSLR Camera.
On a Crop-Sensor Canon Camera the Crop Factor is 1.6 x 50mm.

JD750 Loc: SoCal

Seems correct except the smaller sensor does not really multiply the field of view.

The easiest way to see it is to draw a circle, let that represent the 50 mm lens image circle. Now draw a 3x2 rectangle inside the circle almost touching the edges. That represents the full size sensor. Now draw a smaller 3x3 rectangle inside the first square. That represents the crop sensor. The field of view to the edges of the crop sensor with the 50mm lens, is equivalent to the field of view to the edges of the full sensor with the 75mm lens.

Silverrails

Thanks, it's all over my Head, I suppose when I put my Nikon 50mm 1.8g Lens on my Nikon D3300 "Crop-Sensor Camera it is still only a 50mm 1.8g lens, but when I go to take a Picture of the Lamp on the Living room Table I seem to need to back up a few steps to get the whole lamp correctly in my View. Yes, for some reason that lamp got closer to me when I looked thru my 50mm 1.8g lens on my Nikon D3300 Crop-Sensor Camera??....WHY? For some reason I seemed to somehow get closer to the Lamp, but I never moved any closer, but I had to move Back?..WHY?

I hope this explanation seems more logical to this whole "Crop-Factor" & "Crop-Sensor" Mathematical Measurement of the F.O.V. or as some refer to as D.O.F.
All I know, is if I have 5 patio stones in a row, 1-thru-5, and I am on #5 looking at a Cow, when I look thru the 50mm 1.8g lens on my "Crop-Sensor Camera" I must NOW STEP BACK a Stone or two to have the "whole Cow" correctly in my Vision,.....WHY?... Is this a Change in MY "Field of View" or MY "Depth of Field"??

I certainly hope I am making Sense to SomeOne out there.!!

JD750 Loc: SoCal

Exactly! And the attached pic is why.

From this article:
https://photographylife.com/what-is-crop-factor

(Download)

Silverrails

Thank You for your contribution, that is an excellent illustration showing the aspect of Crop-Sensor Photography.

JD750 Loc: SoCal

You are welcome.

It is said a picture is worth 1000 words.