24 mega pixels APS-C vs 24 megapixel full frame???

[Anon Ymous]

If you use a shorter lens on the cropped sensor to match the angle of view the prints will appear to have the same DOF at different f-stops.

Agreed. Wether this matters or not is debatable. Lots of happy APS camera users out there.

 

[Alan Johnson]

If you shoot both at ,say, f2, an 85mm lens on full frame will give a more blurred portrait background than a 50 mm on cropped sensor. Pros carry this further to 85mm f1.2, presumably because this is what sells.
eg,https://www.blackwaterpromotions.co...=If you were to mount,x, which equals 127.5mm.

 

[Chan Tran]

The full frame has the advantage of being full (although this is only a convention). People use the 24x36mm format as a standard so that all other formats have a crop factor. Even the ridiculous crop factor of less than one for format larger than the 24x36mm.

 

[xkaes]

Shoot any scene with any lens at any f-stop with a 24x36mm format (full-frame). Make an 8x10 print. Then cut the print in half. That half is what you would get from a 24x18mm format (APS). It's the exact same DOF in both.

If you enlarge the APS half to 8x10, you decrease the DOF -- same lens, same f-stop.

 

[koraks]

If you enlarge the APS half to 8x10, you decrease the DOF -- same lens, same f-stop.

No, the DOF doesn't change. But because the part that's in focus becomes a relatively bigger part of the entire image, the DOF appears to have increased.

I guess this is one of those things that we can argue about a long time although we all know exactly what the thing looks like in real life!

Whether the DOF thing is an advantage or a drawback is rather subjective. For instance, I find it an advantage in most of my photography - although I felt the opposite about it a decade ago. My preferences and subject matter have changed over the years, I suppose.

 

[Cholentpot]

If you shoot both at ,say, f2, an 85mm lens on full frame will give a more blurred portrait background than a 50 mm on cropped sensor. Pros carry this further to 85mm f1.2, presumably because this is what sells.
eg,https://www.blackwaterpromotions.com/crop-sensor-vs-full-frame-sensor-lens-focal-length-and-depth-of-field/#:~:text=If you were to mount,x, which equals 127.5mm.

The blurred background is what sells.

Add the magnification that you have to add in to produce the same size print and the DOF is the same. Minox & 16mm cameras have tiny formats, and incredible DOF -- if you only make 3x5" prints. Blow them up and they have the same dof as a 35mm camera.

This isn't how it works. But you do you.

 

[xkaes]

No, the DOF doesn't change.

Of course the DOF changes. As you magnify the image, the circle of confusion increases, so what appears "in focus" decreases. That's why the circle of confusion is very large for large formats (ex., 0.2mm for 8x10) and much smaller for small formats (ex., 0.02mm for APS). You don't have to enlarge an 8x10 negative at all to get an 8x10" print. An APS (24x18") image has to be magnified tremendously.

It's the circle of confusion that determine what appears to be in focus.

Maybe you'll believe Leslie Stroebel. "Cropping the image reduces the DOF". Using an APS format is "cropping the image". But maybe that's just him being him:

 

[Paul Howell]

This kinda gets to my reason for starting this thread.

I'm just now starting to learn about digital cameras. I place very high value on small and light weight. From my point of view, it's very difficult to see any real disadvantage to an APS-C camera that is smaller, lighter weight and less expensive than its nearly equivalently spec'd full frame sibling. Thus, the question.

If you have a Nikon Mirrorless then you have a lightweight camera with great high ISO and AF, unless you want to make really big prints and need all the MP you can get, then what more do you need? In terms of noise, color, all can fixed in post. For travel I still use my Pentax K 2000s. Images will wind up on my wife's Facebook page, a 6MP camera, light, ISO good to 800, with 50mm and 28mm along with 18 to 70 kit lens, works for me.

 

[Cholentpot]

Argue argue argue.

Here's a test. Two cameras, one APS-C one Full frame. Both using the same lens and setting. I tried to approximate the distance offset when using the crop.

Canon EOS 5DMk4, EF 24-70 f/5.0 1/125 ISO100. Lens is set to 50mm

Canon 550D (T2i) EF 24-70 f/5.0 1/125 ISO100. Lens is set to 35mm

Yes, I'm slightly closer using the 5D full frame but look at the difference in background blur. Compare the garage and swing set and the distance between the two shots is not much

Just to try on the pants I got much closer with the APS-C sensor to boost the blur

Go argue over stats and papers. I went out and took the shots to prove my point.

I rest my case.

 

[wiltw]

I see this mentioned a lot. It makes no sense to me. Are these claims assuming that one uses different focal lengths for the different formats? Or is there something else going on?

Using the DOF calculator from Cambridge in Color, the DOF perceived by a person with 20/20 vision (not the poor vision assumed for 'manufacturer standard')

• FF with 100mm f/2.8 lens at shooting distance of 10' has DOF zone of 0.18'
• APS-C with 60mm f/2.8 lens at shooting distance of 10' has DOF zone of 0.31'

both see same Field of View of the scene...FL is appropriate to the smaller frame size of APS-C

 

[xkaes]

One point you need to add -- which is mentioned in the DOF calculator instructions -- is "our eyes can perceive finer detail as the print size increases, and so the depth of field decreases"

Since the APS image must be cropped (magnified by 2X) to create the same size print as a FF image, the DOF decreases. The calculator does not add this factor in.

You need to compare apples to apples.

 

[BradS]

Using the DOF calculator from Cambridge in Color, the DOF perceived by a person with 20/20 vision (not the poor vision assumed for 'manufacturer standard')

• FF with 100mm f/2.8 lens at shooting distance of 10' has DOF zone of 0.18'
• APS-C with 60mm f/2.8 lens at shooting distance of 10' has DOF zone of 0.31'

both see same Field of View of the scene...FL is appropriate to the smaller frame size of APS-C

Makes sense. Thanks. People make it sound as if there were some intrinsic magic in the electronics or something - which is why I asked.

 

[L Gebhardt]

It’s discussed and relevant if you are after the shallowest depth of field for a certain angle of view. You can easily buy an 85mm f/1.4 but not a 55 f/1.0. If that’s not important to you then you get to save some weight in your lenses with the smaller sensor. You can save even more with micro four thirds.

 

[markjwyatt]

I think this is what I was wondering about. Can you elaborate? Why does larger area imply better S/N ?

oh....maybe because more area --> more photons?

Yes, better low light photography. There is a view camera, I think 8x10, has a 12 MP sensor, but is like ISO 100,000 no problem. I saw it (in an article) being used for indoor portraiture using just room light, no issues. An extreme case, but obviously really big pixels.

 

[wiltw]

One point you need to add -- which is mentioned in the DOF calculator instructions -- is "our eyes can perceive finer detail as the print size increases, and so the depth of field decreases"

Since the APS image must be cropped (magnified by 2X) to create the same size print as a FF image, the DOF decreases. The calculator does not add this factor in.

You need to compare apples to apples.

Most DOF calculators assume that -- regardless of the film format -- the print being judged is 8" x 10" viewed from about 10-12'. The 'deeper' DOF (at same aperture and FL appropriate to format size, is at 8x10" print, so although FF is magnified about 8X and APS-C is magnified about 13X to make the same print, APS-C has deeper DOF at that print size.
If FF were enlarged 8X, and also enlarged 13X, the 13X print has a shallower DOF because blur circles are enlarged to a greater degree, so our eyes can detect the blur rather than being fooled to think 'in focus'.

 

[nmp]

Now I understand why they call it the "circle of confusion"....

 

[L Gebhardt]

Argue argue argue.

Here's a test. Two cameras, one APS-C one Full frame. Both using the same lens and setting. I tried to approximate the distance offset when using the crop.

Canon EOS 5DMk4, EF 24-70 f/5.0 1/125 ISO100. Lens is set to 50mm

Canon 550D (T2i) EF 24-70 f/5.0 1/125 ISO100. Lens is set to 35mm

Yes, I'm slightly closer using the 5D full frame but look at the difference in background blur. Compare the garage and swing set and the distance between the two shots is not much

Just to try on the pants I got much closer with the APS-C sensor to boost the blur

Go argue over stats and papers. I went out and took the shots to prove my point.

I rest my case.

Both cameras should have the sensor at exactly the same spot. It looks like you moved the cameras. But even if you did the distant background blur would still be roughly the same as what you show.

 

[warden]

Both cameras should have the sensor at exactly the same spot. It looks like you moved the cameras. But even if you did the distant background blur would still be roughly the same as what you show.

Actually the starter fluid moved. Looks like the cameras didn't.

 

[warden]

I went out and took the shots...

Thanks! That's very helpful.

 

[Cholentpot]

Both cameras should have the sensor at exactly the same spot. It looks like you moved the cameras. But even if you did the distant background blur would still be roughly the same as what you show.

I did my best to try to keep them relative. This wasn't exact science it was just to prove a point. But yeah, the background blur on FF is different from APS-C. Enough to warrant spending the extra money and larger size? That's up to you, I think so.

Actually the starter fluid moved. Looks like the cameras didn't.

Can is in the same position on photo 1 and 3 for sure. Not sure about photo #2.

Thanks! That's very helpful.

Charts and calculators are all very well and good but in the end the photos show what the reality is. After all, we're talking about photography which is a visual medium.

 

[wiltw]

I did my best to try to keep them relative. This wasn't exact science it was just to prove a point. But yeah, the background blur on FF is different from APS-C. Enough to warrant spending the extra money and larger size? That's up to you, I think so.

A concept not widely understood by photographers is that appearance of a photo is determined by

A) NOT MERELY 'what is in focus...the DOF zone depth', but also ​

B) how out of focus is the 'not in focus' background and foreground !​

​

In my post #60, I responded to #BradS question within the context of Depth of Field difference. The Blur (that which is 'out of focus' to our eye/brain) has a difference as well, which is driven by the Aperture Diameter (not driven by f/number). Using the 100mm f/2.8 and 60mm f/2.8 examples from post #60

• FF 100mm f/2.8 has a calculated 35.7mm aperture diameter
• APS-C 60mm f/2.8 has a calculated 21.4mm aperture diameter

In this case, APS-C image has deeper DOF zone than FF, and the background blur (what appears to us as 'out of focus') is MORE BLURRY in the FF image than in the APS-C image...the larger diameter opening of the FF FL causes the farfield to be more blurry than the APS-C FL diameter! I illustrate with these two photos (Canon 5D vs. Canon 40D -- somewhat similar pixel counts) both output from Lightroom as 1600 x 1200 images for posting at very similar subject sizes

FF

APS-C

Point of focus was on the same bloom. Forward book is at 60", focus bloom at 72", rearward book is at 89". Fully visible blossoms are positioned 69" - 75" from focal plane.

1. 20/20 DOF zone is 70.9" - 73.2" on APS-C, while it is 71.3 - 72.7" for FF.
2. Note the nearfield just outside the near DOF, note the farfield just outside the DOF, and note the out-of-focus coffee table and rail, and the distant out-of-focus background hills.

 

[Cholentpot]

A concept not widely understood by photographers is that appearance of a photo is

A) NOT MERELY 'what is in focus...the DOF zone depth', but also ​

B) how out of focus is the 'not in focus' background and foreground !​

​

In my post #60, I responded to #BradS question within the context of Depth of Field difference. The Blur (that which is 'out of focus' to our eye/brain) has a difference as well, which is driven by the Aperture Diameter (not driven by f/number). Using the 100mm f/2.8 and 60mm f/2.8 examples from post #60

• FF 100mm f/2.8 has a calculated 35.7mm aperture diameter
• APS-C 60mm f/2.8 has a calculated 21.4mm aperture diameter

In this case, APS-C image has deeper DOF zone than FF, and the background blur (what appears to us as 'out of focus') is MORE BLURRY in the FF image than in the APS-C image...the larger diameter opening of the FF FL causes the farfield to be more blurry than the APS-C FL diameter! I illustrate with these two photos (Canon 5D vs. Canon 40D -- somewhat similar pixel counts) both output from Lightroom as 1600 x 1200 images for posting at very similar subject sizes

FF

APS-C

Point of focus was on the same bloom. Note the nearfield just outside the near DOF, note the farfield just outside the DOF, and note the out-of-focus background rail and the distant out-of-focus background hills.

Look at the book behind the flowers and compare between both photos. Now look at the leaf.

This answers the depth of field debate once and for all. We can all move on and argue the other points and differences.

 

[BradS]

...but that's comparing a 60mm focal length to a 100mm focal length. The bokeh and DoF differences would have been there even if both photos were made with the same camera. Thus, the observed bokeh and DoF results are completely independent of the camera. It is not the APS-C camera that has more DoF; it is the lens used. It is very misleading/confusing/wrong to say, "the APS-C camera will have greater DoF". It is not the camera. It is the lens.

 

[xkaes]

As I said, they are comparing apples and oranges. Use the same lens at the same f-stop, one FF & one APS. You have to magnify the APS image 2X to get the same size print -- and DOF decreases due to the increased magnification, as Stroebel points out in his book (above). The circle of confusion increases and the DOF decreases -- with magnification or cropping. It's not rocket surgery.

 

[MattKing]

As I said, they are comparing apples and oranges. Use the same lens at the same f-stop, one FF & one APS. You have to magnify the APS image 2X to get the same size print -- and DOF decreases due to the increased magnification, as Stroebel points out in his book (above). The circle of confusion increases and the DOF decreases -- with magnification or cropping. It's not rocket surgery.

If you have a file - or negative - that you are printing from, it will record detail with varying amounts of detail, acutance and blur. And the result will have characteristics that we recognize as showing depth of field.
When you magnify that file or negative to print it, it will magnify the detail, acutance and blur.
But that magnification gives different results than changing the depth of field behavior of the recorded image.
The results look different when you print the two versions.
Anyone who has tried to do life size close-up work with a contact printed 4x5, and then done the same work with an enlarged 35mm negative will recognize the difference.