Crop Sensor Camera with Full Frame Lens Question

[smoke665]

twice refer to effective zoom

You are correct he did say this, but he said "zoom"....no where did he use FOV. He further went on to contradict with "So the cropped sensor R7 has a "better reach". I'm assuming he in fact does know, but merely misstated.

Upscaling does not add any real detail it just estimates what might be there

I've used upscaling numerous times and of late found it to be helpful. The latest algorithms and AI can greatly enhance details, sharpness, and in some cases reduce artifacts.

 

[Dikkie]

If you take a photo with a 50mm lens and then a 24mm lens from the exact same place and then crop the 24mm photo to have the same field of view as the 50mm photo you will have two photos with identical perspective.

Theoretically yes, but when you do the test, the object you're photographing will look slightly different in the end result.
And the bokeh, very important, is very different too.

 

[MontanaDave]

Take a 600mm lens with the full frame Canon R5 versus the crop sensor Canon R7.
The R7 full frame is 32.5mp, crop factor 1.6. The R5 full frame is 45mp.
The field of view of the R7 is narrower, so the effective field of view would be the 1.6 X 600 = 960mm at 32.5 mp.
With the R5, you can shoot in 1.6 crop mode to get the same field of view, but you would only have ~18mp in the photo.
That has been my experience with my R5 and R7 and a 600mm lens.

 

[Ysarex]

Theoretically yes,

There's nothing theoretical about it. In practice; if you don't move the camera you don't change perspective.

but when you do the test, the object you're photographing will look slightly different in the end result.

It will not. If one of the lenses you use is poor quality and full of distortion that could show. Use good lenses and the object photographed will appear the same in both photos. In the illustration below I used my 58mm and 40mm lenses on a FF Nikon Z7. The cropped image from the 40mm lens aligns with the image from the 58mm lens nearly pixel for pixel. The object photographed is the fish. I didn't bother to match the DOF since the topic is perspective, but that would also be possible.

And the bokeh, very important, is very different too.

Or very unimportant. Bokeh results from the physical characteristics of each specific lens and of course must be different for all lenses. You can't use two different lenses and match bokeh.

 

[greybeard]

Coming from one who shoots both crop and full frame, it all comes down to one (1) stop assuming the cameras are running the same processors like expeed 6. A full frame normal lens is usually a 50mm and a aps-c is a 35mm. Each will produce a picture with the same field of view. But, the Depth Of Field (acceptable focus) will be 1 stop deeper with the 35mm than the 50mm. As an example the 35mm at f/5.6 will have the same DOF as the 50mm at f/8. So if Bokeh is your thing then it will be easier to get that creamy background with a FF (FX) than an aps-c (DX). Shadow recovery is about 1 stop better with FX than DX in other words iso 3200 on DX will look similar to 6400 on FX. However, noise reduction has gotten so much better these days that it isn't as big a deal as it use to be. These things are true no matter if you are using a DX or FX lens on a DX camera. When using a FX lens on a DX camera the sensor only records the center of the image and ignores the edges and corners. A so so FX lens will often perform better on a DX body because the corners and edges are where many lens defects show up. I use FX lenses on my Z50 (DX) all the time with great results.

Shot with a Z50, ftz, af-s 200-500 f/5.6 @ 500mm, f/5.6, 1/2000, iso 800

 

[zombiesniper]

It amazes me all the features on these cameras. I am in no hurry to "upgrade" as I've only had this camera a couple of years and only recently decided I needed to really learn how to use it.

I figure that I will figure out what I like and don't like as I go.

So far I have mainly shot in the "semi auto" modes, mainly Aperture Priority as well as the "full auto/no flash" with the auto focus off. Yeah, I like manually focusing, weird right?

I have decided that the camera in auto, while doing a decent job, sometimes does not quite get it the way I want it.

So at this point I am not sure if it is me or the settings I've chosen or even the lens that is the weakest link.

The fun will be in figuring it all out!

 

[zombiesniper]

No matter what you do, Hobby, job, etc.
This kind of outlook will serve you well.

 

[Dikkie]

Bokeh results from the physical characteristics of each specific lens and of course must be different for all lenses. You can't use two different lenses and match bokeh.

Ok, but regardless of the bokeh it produces, the depth of field is different with a different focal distance.

Changing the focal point of a lens while maintaining the same object will result in a different depth of field. A wider aperture (smaller f-number, like f/2.8) will produce a shallower depth of field, meaning only a narrow range of distances will be in focus, while a narrower aperture (larger f-number, like f/16) will produce a deeper depth of field, where a larger range of distances appear sharp.
In essence, changing the focal point (by adjusting focus) will change the distance that is perfectly sharp, and therefore the depth of field will shift as well. The depth of field will be narrower or wider depending on the chosen aperture setting and the distance to the subject.

So therefore, just cropping the image isn't the way to go for me, as you will get a different result.

 

[smoke665]

full frame normal lens is usually a 50mm and a aps-c is a 35mm. Each will produce a picture with the same field of view.

You're forgetting the effect of distance to subject on focal length/Fov. To get the same FOV comparison you have to increase the distance on the 35mm Aps-c for equivalent FOV to the 50mm full frame. When you do that you have to open the aperture on the 35mm to maintain equivalent DOF.

 

[Ysarex]

Ok, but regardless of the bokeh it produces, the depth of field is different with a different focal distance.

Changing the focal point of a lens while maintaining the same object will result in a different depth of field. A wider aperture (smaller f-number, like f/2.8) will produce a shallower depth of field, meaning only a narrow range of distances will be in focus, while a narrower aperture (larger f-number, like f/16) will produce a deeper depth of field, where a larger range of distances appear sharp.
In essence, changing the focal point (by adjusting focus) will change the distance that is perfectly sharp, and therefore the depth of field will shift as well. The depth of field will be narrower or wider depending on the chosen aperture setting and the distance to the subject.

The point of the exercise -- maintaining the same perspective with two different focal length lenses and then cropping to equivalent content -- requires the camera position and therefore subject distance to remain unchanged. Both lenses are in focus on the same subject at the same distance. At the same f/stop the DOF will not be the same. Three things will change the DOF, the reduced magnification and smaller physical aperture of the shorter lens and the final crop of the image from the shorter lens. That can however be compensated for by determining and setting a smaller aperture, stopping down, the longer lens (or larger aperture for the shorter lens). Then the two images will be the same.

So therefore, just cropping the image isn't the way to go for me, as you will get a different result.

Or set different f/stops on the two lenses to compensate the DOF difference, then do the crop and get the same result.