Is There Such Thing As a "Best" Normal Lens for Crop?

[Zv]

I've noticed that about 50mm on crop or 70mm on FF seems to match the magnification of my eye. In other words, if I look at an object with my naked eye and then through the viewfinder, it appears the same size in my field of vision.

That's going to depend on the viewfinder magnification. For example, the 7D has a 1x magnificaiton, whereas the T5i/700D's VF mag is only 0.85x.

Thanks for this link to luminous lanscape, it was a very informative read! Afterwards I looked up my 7D and 5D2 manual for the viewfinder specs. 5D2 could be better!

 

[Cory]

While I'm at it should I get a 2-stop ND filter for waterfalls? I'll likely generally try to get these shots earlier or later in the day; hopefully.
Thanks.

 

[Loswr]

While I'm at it should I get a 2-stop ND filter for waterfalls? I'll likely generally try to get these shots earlier or later in the day; hopefully.
Thanks.

Depends on how much blur you want... I'd think at least 3 stops, I sometimes use 10 stops for waterfalls. A CPL is usually very good for waterfall shots (cuts down on the reflections from water and rocks, and increases saturation of foliage, etc.), and the CPL will cut ~1.75 stops. The 17-55mm is not an ultrawide lens, so as long as you're not planning to use it on a 10-22mm, you might consider a variable ND filter (B+W, Tiffen, or Singh-Ray, skip the Fader/Genus/etc. versions).

 

[jd7]

Setting aside the question of a "normal" human field of view (I personally can't imagine a rectangular sensor producing anything like it), I've noticed that about 50mm on crop or 70mm on FF seems to match the magnification of my eye. In other words, if I look at an object with my naked eye and then through the viewfinder, it appears the same size in my field of vision. Does anyone know the correct term for this "normal" magnification concept?

I'm not sure I'm correct about this but ... My understanding is that around the 40mm to 50mm focal length - on a 35mm sensor - gives an angle of view (correct expression?) such that the relative sizes of objects at different distances is about the same as what the human eye/brain perceives, and that's what gives the name "normal lens" to lenses around that focal length.

Have a look at the TDP review of the Canon 40mm pancake lens -
http://www.the-digital-picture.com/Reviews/Canon-EF-40mm-f-2.8-STM-Pancake-Lens-Review.aspx
and compare the scene shot at 35, 40 and 50. The framing of the foreground is about the same in each case, but the objects further away appear less or more "magnified".

If I'm right, my assumpion is the formula posted earlier in the thread works (assuming it does) because it reflects this. I haven't tried to do the maths though.

Perhaps I'm wrong? If so, can anyone explain further?

In terms of field of view , I think human vision is generally a wider field of view than that of a 40mm or 50mm lens, ie a 40mm or 50mm lens (on a 35 mm sensor) gives effectively a crop of what human vision would perceive.

Thanks.

PS - Neuro has already responded about the effect of viewfinder magnification, so my post has nothing to do with that issue.

 

[jd7]

My favorite normal lens would be the Canon 28mm F1.8 USM. It's not as sharp as my 50mm but very near it in terms of sharpness. It's not too wide nor too tight for a crop. I've tried the almost similar Sigma 30mm F1.4 and don't like it that much. The Canon is simply smoother and focuses faster even in low light. I've used the 17-55 and 15-85 and found that I like both. They're just too expensive for me to invest something that I'll not use in the future (6D is coming)...

While I agree with the idea there is no "best", I also think the 28 1.8 makes a very good "normal" lens on APS-C sensor cameras, at least if you don't want to carry the bulk of the 17-55 2.8 (which I think is an excellent zoom lens). I have never tried the Sigma 30 1.4 to compare though.

 

[verysimplejason]

My favorite normal lens would be the Canon 28mm F1.8 USM. It's not as sharp as my 50mm but very near it in terms of sharpness. It's not too wide nor too tight for a crop. I've tried the almost similar Sigma 30mm F1.4 and don't like it that much. The Canon is simply smoother and focuses faster even in low light. I've used the 17-55 and 15-85 and found that I like both. They're just too expensive for me to invest something that I'll not use in the future (6D is coming)...

While I agree with the idea there is no "best", I also think the 28 1.8 makes a very good "normal" lens on APS-C sensor cameras, at least if you don't want to carry the bulk of the 17-55 2.8 (which I think is an excellent zoom lens). I have never tried the Sigma 30 1.4 to compare though.

The Sigma 30 1.4 is definitely sharper and has less CA than the Canon 28mm F1.8 (probably due to CA). However, the Canon as I said is much better mechanically and AF is a lot faster. With a little bit of time in LR, you won't notice the IQ difference at all unless you really pixel peep (200%?). They cost essentially the same. I have the 28mm F1.8 and the 50mm F1.8 II combo when I want maximum IQ and lightness while bringing my 500D. Night or day, they're perfect for me.