R U Thinking f/1.4? F-Stop Blues......

rexbobcat

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I've been doing it wrong for so long, and it's been working for me... D:

Damn real world application versus hypothetical and controlled testing!
 

Sw1tchFX

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Ss I guess DOF has nothing to do with getting faster lenses?
 

Garbz

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I've been doing it wrong for so long, and it's been working for me... D:

Damn real world application versus hypothetical and controlled testing!

A lot of photographic effects aren't visible in real real world applications due to the way we look at images. The result would be a physically darker image the camera can't compensate for since it assumes a linear relationship between the the shutterspeed and aperture. I'd be interested to see the side by side comparison of the worst and best case images taken at the same settings. You may not see the problem until you see the solution.

This is similar to edge sharpness being not really field relevant unless they are horrendous, simply because people don't look at the edge of the image. Or not realising the white balance of the image is slightly wrong if you have nothing to compare against (there's a reason photoshop's background is middle grey rather than some colour).
 

2WheelPhoto

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So an f1.4 lens being shot at f2ish may have a better quality/sharpness as a result of being stopped down a little, PLUS picture overall BETTER lighting!?
iconhammer.gif
 

analog.universe

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So an f1.4 lens being shot at f2ish may have a better quality/sharpness as a result of being stopped down a little, PLUS picture overall BETTER lighting!?
iconhammer.gif

Not exactly... this article just shows that on a very dense sensor, f/1.4 is at worst, only .4 stops brighter than f/2.0, instead of a full stop. On a less dense sensor, you lose even less. This illustrates the diminishing returns of larger apertures. You still get more light with larger apertures, and on sensors that are not super dense, you get almost as much as you think you should.

I do think some of this has to do with the lens as well.... that wasn't a variable that was much explored in this article. When I was reading tests of the Sigma 20mm f/1.8, corner vignetting wide open was so intense that the _average_ brightness across the frame was the same at 1.8 as it was at 2.5, but the center was still brighter at 1.8.

I'd like to see comparisons of 1.4s known for strong vignetting (like a Canon 24L...) against 1.4s known for weak (obviously relative at 1.4) vignetting (like a Zeiss 85 Planar).
 

nickzou

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God damn it... should've just got the 50 1.8G if this is the case. 1.4 is sometimes excessively shallow depth of field anyways.
 
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KmH

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I've been doing it wrong for so long, and it's been working for me... D:

Damn real world application versus hypothetical and controlled testing!
Or is that real world guessing, hoping, and wishing compared to controlled testing? :lmao:
 

DiskoJoe

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God damn it... should've just got the 50 1.8G if this is the case. 1.4 is sometimes excessively shallow depth of field anyways.

This is actually a good point. But it would depend on your camera. Some did better then others. Plus the wider primes usually have nicer glass. So you would still benefit from that even if you lose a bit of light.

I would like to see someone do a really comprehensive test on this subject where you see full brand line ups and see how the lenses stack up on each.
 

analog.universe

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God damn it... should've just got the 50 1.8G if this is the case. 1.4 is sometimes excessively shallow depth of field anyways.

This is actually a good point. But it would depend on your camera. Some did better then others. Plus the wider primes usually have nicer glass. So you would still benefit from that even if you lose a bit of light.

I would like to see someone do a really comprehensive test on this subject where you see full brand line ups and see how the lenses stack up on each.

And the 1.4 still gets you more light than the 1.8, no matter what body you put it on. Not the full 2/3 stop more, but still more.
 

jake337

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Hmmm. What about lens with larger than f1.4 apertures. F1.2, f1.1, f1.0, f.95? It also specifically states digital sensors, what about film?
 

Derrel

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God damn it... should've just got the 50 1.8G if this is the case. 1.4 is sometimes excessively shallow depth of field anyways.

The 50mm 1.8 F-S G is the NEWEST and most-sophisticated 50mm lens design Nikon has made...it has a fairly sophisticated design (not an econo-design like say the old Canon 50/1.8 EF-II, which is a cheezy 5-element design that was outdated 30 years ago...) the new 50/1.8 has an aspherical element design, which the 50/1.4 AF-S G does NOT have...I saw not too long ago a multiple 50mm lens test, I believe 7 different 50mm lenses, including a new "Zeiss" design in F-mount, a 50/1.4 Planar, made by Cosina in Japan, to Zeiss specs...the winner OVERALL, in ALL performance categories combined...was....the brand new 50mm 1.8 AFS-G Nikkor...

Looking at that DxO Mark testing article, I noticed the good old 5D and the Nikon D3 bodies were very,very close, and at the top of the efficiency rankings...it's interesting that the original 5D's 12.8 MP sensor is just a little bit lower in performance than the 12.2 MP sensor of the Nikon D3...those monster-sized pixels in those two FX designs have proven themselves to be about as good as can be made for low-light or high-ISO or wide-aperture work...

The original post KmH made dovetails in with something I was reading last week elsewhere: a guy was suggesting that users carefully test their OWN cameras in low to moderate light levels, at different apertures, to see how color rendition was affected, sometimes quite significantly, at f/4 and then at wider apertures...and not just "some guy", but a very experienced photographer whose opinion I respect. I believe, looking at the DxO Mark graph, that the small-sensor, high MP count sensors are losing 4/10, to 9/10th of an EV value at wider apertures...and if what DxO Mark is true, this other photographer's own actual real-world tests, which show WORSE COLOR at wide apertures in less-than-ideal lighting conditions, are probably due to what DxO Mark has stated: that the CAMERA MAKERS are CHANGING the ISO gain setting at wide apertures without stating that fact!!!! Yikes!!! Elevation of the ISO level is one of the quickest ways to watch one's color richness and saturation go to hell; above XXX or XXXX ISO levels, and the color on the majority of d-slrs takes a huge,huge hit--even WITH good, generous exposures...

Once again...we've got people making jokes about scientific testing, and we've also got really advanced, critical workers who have noticed that the linear exposure response we see at medium to small apertures does not actually exist at the widest apertures, and now DxO Mark is telling us that the camera makers are messing with the ISO gain control to either "overcome" or to "hide" this lack of linear exposure at wide apertures; those big, fast f/1.4 lenses sell for tons of money...The big camera makers can't have the rabble realizing that another $1,000 spent on an f/1.4 lens really does NOT GIVE THE USER a TRUE two f/stop gain in light gathering compared to what a modestly-priced f/2.8 lens does....
 

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