Question of f1.4 vs f1.8

I have this question which I'm struggling to find answers:

What's so special about f1.4 lens vs f.18 - w.r.t Nikon 50mm primes. The first one costs almost twice the second, AF-S versions..

• If I shoot at f/2, does the f1.4 lens have any advantage over f1.8 at that aperture value?
• The f-stop kept the same (f/3 for example) does the f1.4 lens have advantage over f1.8 in terms of image quality, sharpness, bokeh, etc?
• The f-stop being the same. does the f1.4 lens focus faster than the f1.8?

Fundamentally, if I am content with shooting at f/2 or greater, what specific advantage does the f1.4 lens offer?

Thanks!

Some F1.4 lenses are sharper at F2 than the equivalent F1.8 lenses. Maybe. Usually the 1.4 lenses have an advantage at 1.8 over the 1.8 lenses.

If you aren't going to shoot at F1.4, it doesn't make much sense to buy an F1.4 lens when a good 1.8 equivalent exists.

Reviews and samples differ, but I think most people find that the 50 f/1.8 isn't a great performer until it's stopped down to below f/2.8 or so. The 50 f/1.4 is generally regarded as adequete wide open. SLRgear has very similar corner sharpness starting at f/4. The exception is in distortion where a given 50 f/1.8 are generally unbeaten.

Like most things, camera lenses are subject to diminishing returns. In other words, making something that is pretty poor slightly better has a much better rate of return than taking something good and making it excellent. 5 minutes spent by a lazy child cleaning a filthy room will make an immediate obvious difference, 30 minutes spent prepping an operating room requires lots more training (so you don't mess something up) and isn't as likely to be obvious to a casual viewer.

Having the ability to go from f/1.8 to f/1.4 and having better sharpness from say f/2.8 to f/1.8 might not be worth double the money to most buyers, and it's going to require at a minimum more expensive optical glass (the front element is going to have to be a 65% bigger circle and likely thicker) and because it's needed by fewer users, any extra R&D costs are going to be spread across fewer units.

Welcome to the forum

Following on from Craig's comment, the 50mm f/1.8 is a good value and
a fine lens. At f/2, the f/1.4 lens will be sharper than the f/1.8 at f/2.

Much user opinion/experience and reviewer testing suggests that IQ for both
lenses is very close in by the time you get to f/4 and beyond.

In general, the main reasons you might go for the f/1.4 are :
1/ creamier bokeh at f/1.4 to f/1.8.
2/ You need better light-gathering capability for inside events, non-flash
shooting, night street shooting, etc.
3/ You need faster shutter speeds offered by the f/1.4 in similar lighting
situations.

Both lenses have adequate AF - not sure that you would notice a difference,
the dp review here suggests that the 50mm AFS-G may have slightly slower
AF than its predecessor lens the AF-D.

http://www.dpreview.com/lensreviews/nikon_50_1p4g_n15/page5.asp

In the end, if you shoot at f/2 with the f/1.4 lens, the shutter speed will
be faster, enabling a greater number of blur-free images, and those images
will be sharper. With most lenses, the more you stop down, the sharper
the image.

Good luck in your research
Keith

--
. . .

The 1.4 gives a slightly brighter viewfinder image & may focus faster/more accurately in low light situations. The 1.4 is meant for available light shooting, so the only real advantage is wide open. When stopped down the difference will be dependent on the quality of the lens, not the aperature.

Perhapa Op is thinking of this new 50mm f/1.8 whose performance is an unknown at present.
http://www.dpreview.com/news/1104/11042710nikon50mmf1p8.asp
--
Dave
http://www.rosser.pwp.blueyonder.co.uk
http://www.pbase.com/dgrosser

@David - Yes, I'm talking about the upcomming f1.8 AF-S Nikkor 50mm

Subjectively speaking, I would say the f1.4 is fully usable at > f1.8, the (current) f1.8 from > f2.5 if centre sharpness is required to a high degree...that makes the f1.4 capable of working in half the light of the f1.8 (one full stop). That makes a lot of difference in low light, if you can afford the f1.4, go for it I say. It's a lot of lens for the money. The 1.8 is great too though, as is the 85mm f1.8 which is a better choice for portraits than a 50mm.

While we're at it, does anyone see a big difference in the 1.4D vs. the new 1.4G glass?

PHXAZCRAIG said:

Some F1.4 lenses are sharper at F2 than the equivalent F1.8 lenses. Maybe. Usually the 1.4 lenses have an advantage at 1.8 over the 1.8 lenses.

Click to expand...

This is only because The f/1.8 lenses are designed to be inexpensive. Nikon's f/2 and f/2.8 lenses are quite good. I'd rather use lenses that are stellar at f/2 than compromised in size, weight and overall optical performance due to f/1.4 . A lens manufacturer really can't have so many lens lines (f/1.4 pro, a cheaper f/1.8, f/2 pro, f/4 cheap/pro), so we're stuck with optical products that aren't as great as they could be.

In a comparison of the f/1.4D and f/1.8D on FX, photozone shows that the f/1.8 has similar or better center sharpness but worse edge and border sharpness. Bokeh and other quality issues aside, there is little difference in resolution despite some perception tests 5 (?) years ago that showed that the f/1.4D was sharper below f/4 despite photozone revealing the difference is so slight. The same goes for the bokeh, for which everyone raved about the f/1.4D . Thanks, photozone.de . I have both the f/1.8D and f/1.4D as well as the Sigma 50mm f/1.4 .

Here are a few recent shots taken at high ISOs, all wide open -









As long as the ISO is not at 1600 on my D80, I am quite satisfied with the results. But that is me.

From personal experience I've owned the 50 1.8 and 50 1.4G (which I own now). For me, it was worth the money to go with the G. I was not happy with the sharpness on the 1.8 unless stopped down a couple of stops, but I am very pleased with the sharpness on the 1.4 wide open.

I like shallow DOF and the 1.4 gives me that, and low light shooting without the cost of soft images.

Best,

Don

edit: on focus speed... I never used the 1.8 for indoor basketball, but I use the 1.4G all the time and have a high rate of keepers.

Image shot at 1.4 and a gallery below of 50G







50

jjjohn said:

I have this question which I'm struggling to find answers:

What's so special about f1.4 lens vs f.18 - w.r.t Nikon 50mm primes. The first one costs almost twice the second, AF-S versions..

• If I shoot at f/2, does the f1.4 lens have any advantage over f1.8 at that aperture value?
• The f-stop kept the same (f/3 for example) does the f1.4 lens have advantage over f1.8 in terms of image quality, sharpness, bokeh, etc?
• The f-stop being the same. does the f1.4 lens focus faster than the f1.8?

Fundamentally, if I am content with shooting at f/2 or greater, what specific advantage does the f1.4 lens offer?

Thanks!

Click to expand...

Watch these I trust their reviews!!!

Nikon 50mm ƒ 1.8D AF
http://www.youtube.com/watch?v=xKa0cDjdFhs

Nikon 50mm ƒ 1.4D AF
http://www.youtube.com/watch?v=QzqdPu50lTE

Nikon 50mm ƒ 1.4G
http://www.youtube.com/watch?v=8yJi8ODrxX0

The two lenses are different animals. The only thing they have in common is focal length. Too much is made of the 2/3 f-stop between f:1.4 and f:1.8. Look at the diagrams of their innards. They have different numbers and arrangements of the internal elements. The 50mm f:1.4 feels and is more solid. Both are good lenses but I've got the f:1.4.

Bruce

As regards 50mm the optical designs are very different.

The f1.8 is a symmetrical lens design very good at minimum focus or on extension tubes.

The more complex f1.4 does not hold corner quality well at minimum focus especially wide open.
--
Leonard Shepherd

Good photography is mainly about doing simple things well. The challenge is doing simple things well enough for good results.

Leonard Shepherd said:

As regards 50mm the optical designs are very different.

The f1.8 is a symmetrical lens design very good at minimum focus or on extension tubes.

The more complex f1.4 does not hold corner quality well at minimum focus especially wide open.
--
Leonard Shepherd

Good photography is mainly about doing simple things well. The challenge is doing simple things well enough for good results.

Click to expand...

The OP is actually talking about this 50mm f/1.8 which has only just been announced (see one of his replys above)
http://imaging.nikon.com/lineup/lens/singlefocal/normal/af-s_50mmf_18g/index.htm

Though still classic double gauss construction it is a more complex lens than the previous 1.8s 7 elements in 6 groups including an aspheric element. Be interesting to see how it performs though the MTF curves on the Nikon site indicate it is sharper at f/1.8 than the f/1.4 is at f/1.4
--
Dave
http://www.rosser.pwp.blueyonder.co.uk
http://www.pbase.com/dgrosser