EF vs. EF-S Lens On APS-C DSLR

[q.g._de_bakker]

Nothing you wrote actual contradicts what I wrote.

 

Take a hypothetical pair of sensors with identical pixel pitches, one crop and one FF. Take the same shot with the same lens from the same location. Crop the latter to the dimensions of the crop. How are the images different? Not at all. You achieve the identical AOV in the completed image, just by different methods.

 

So why do wildlife photographers often prefer to use crop sensor cameras? Depends on the circumstance, but one reason is often pixel pitch.

No. It is because of the tighter framing without having to use a longer lens to achieve that. Reach.

[rodeo_joe1]

All else equal, the larger sensor will be more sensitive, as it has more area to collect light.

 

But sensor technology evolves, so all might not be equal.

 

You need a longer focal length lens to get the same field of view with a larger sensor.

 

The same f/stop value gives you the same amount of light per sensor area,

but for a longer lens, you need a larger real, physical lens diameter.

 

The lens is now longer, larger around, and a lot heavier.

It is harder to hold and to move around.

The best and most expensive optics in the world are irrelevant if the block of air between camera and subject is polluted, misty, or contains schlieren imhomogenities (turbulence, in short). Depending where you live, perfect 'seeing' may only exist during daylight hours for a few days per month, and then only around dawn or late evening.

 

In general: Less distance=less air=better IQ.

Therefore getting closer is almost always better than fitting a longer lens or using a smaller sensor.

So why do wildlife photographers often prefer to use crop sensor cameras?

It's not just the pixel density. Depth-of-field varies approximately as the inverse square of focal length.

 

This is the setup from my D-o-F spreadsheet, keeping the aperture @ f/4 and doubling the focal length each row from 100mm:

 

And the resulting depth-of-field, assuming the same final viewing size:

 

So using a shorter focal length, proportional to the crop or sensor size, gets you far more depth-of-field for a given aperture; as well as allowing a smaller, lighter and cheaper lens.

 

It really doesn't matter if you change camera or crop from a larger sensor. As long as the pixel size is small compared with the circle-of-confusion chosen for the final 'print' size.

Edited August 13, 2022 by rodeo_joe|1

[BeBu Lamar]

I didn't suppose they could be mounted - it would be odd to allow it when they won't cover. I only have an APS-C mirrorless (and so far only one full-frame EF lens); but I understood the same adapter will do for EF-S and EF lenses. Is that wrong - would I need another adapter for EF-S lenses?

They don't allow it because some of the EF-S lenses protrude into the mirror box and the FF has larger mirror that could interfere. Nikon allows you to mount DX lenses on FX body and you can either accept the vignetting or it would automatically crop for you.

[William Michael]

Just on the topic of - mounting EF-S and EF Lenses on Canon DSLR Bodies:

 

When discussing what lenses mount to what bodies, I think it is important is to understand this concerns the EF-S and EF bayonet mounts.

 

Hence importantly differentiating that these are terms for Bayonet Mount Nomenclature and that in other situations, the terms 'EF-S' and 'EF' are often casually used to describe various lens's Image Circle Coverage - i.e. (EF-S) have an APS-C Format Image Coverage; and that lenses (EF) have a 135 Format Image Coverage.

 

I think that this casual interchange of terminology "EF-S" and "EF" to describe the Image Circle Coverage can lead to confusion.

 

Additionally, for interest's sake:

 

- No Canon EF-S Mount Lens will mount on any Canon 'full frame' Format DSLR, (neither will any EF-S lens mount on any Canon APS-H Format DSLR).

The underlying design feature driving probably is that Canon EF-S lenses have a protruding rear element which might hit the mirror; certainly every EF-S lens I have tested does: but the fact is the, the Bayonet Mounts of the EOS range of 'full frame' cameras only allow the EF Lens Mount, because the bayonet mounts - "EF-S and "EF" are different.

 

- The inverse statement to the above is incorrect: i.e. "all Canon EF-S Lenses will mount on all Canon APS-C DSLR bodies" is incorrect.

Canon developed (many years ago) a few APS-C DSLR bodies which only have an EF Bayonet Mount.

 

- It is correct that all APS-C Bodies including and since the EOS 20D, have a dual bayonet mount and will mount both the Canon EF-S and EF Lenses

 

- There are Canon (and also third party) accessories, (such as Extension Tubes, Tele-extenders and the like) which also will (should) describe in their specification, whether, on the female end, they accept only EF or both EF and EF-S Lenses

 

- There are third party manufactures which make lenses with an APS-C, Image Circle, as far as I have researched each of these lens's release, all made to fit Canon, are supplied with Canon EF Bayonet Mounts, hence these lenses can be mounted and work on canon 'full frame' cameras - albeit with an optical vignette.

 

WW

[glen_h]

There were also, before the DSLRs, actual APS film SLRs.

 

I am not sure if they use EF, EF-S, or some other mount.

 

(Which mostly matters only if you have some APS film.)

[William Michael]

That's a blast from the past - odd cameras -

 

From memory - The EOS IX and EOS IX Lite were the only Canon SLR Advanced Photo System (APS) Format cameras: released circa. 1995.

 

I reckon it is very safe to assume both these cameras would have accepted only EF mount Lenses, because,

1. 1995 was before the EF-S Mount was developed, and

2. both cameras were part of the EOS Series of Cameras - by definition all in the EOS Series of Cameras must accept the EF Mount.

 

WW

Edited September 16, 2022 by William Michael

[glen_h]

That's a blast from the past - odd cameras -

 

From memory - The EOS IX and EOS IX Lite were the only Canon SLR Advanced Photo System (APS) Format cameras: released circa. 1995.

 

I reckon it is very safe to assume both these cameras would have accepted only EF mount Lenses, because,

1. 1995 was before the EF-S Mount was developed, and

2. both cameras were part of the EOS Series of Cameras - by definition all in the EOS Series of Cameras must accept the EF Mount.

 

WW

 

Yes, it seems to be EF:

 

EOS IX - Canon Camera Museum