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Choosing between 50mm 1.8f and 1.4f

PostPosted: Sun Apr 03, 2005 6:20 pm
by DanielA
I've been thinking about getting a fast 50mm lens for my D70, for those times indoors when a flash isn't appropriate. I never really do portraiture shots, but the 50mm x 1.5 I think should be good for stages and dark places.

I have read both here and other forums that the 1.8f is quite good and was planning to get one, but I then ran into these comparisons with the 1.4f:
- http://www.domain-a.de/img/d70_50mm_sidebyside.jpg
- http://forums.dpreview.com/forums/read.asp?forum=1030&message=12218849

They seem to show the 1.4f being much sharper than the 1.8, which looks quite soft when opened up. Since I'll mainly be using it in darkish places, it looks like the 1.4f is way to go.

But other sites say that the 1.4f is now being made in China (not Japan) and the make quality is not as good.
- http://www.kenrockwell.com/nikon/5014af.htm

So, do I pay more for the 1.4f, which looks like it is sharper but not very good built quality? Or should I go with the 1.8f that is cheaper, popular, but softer?

Any suggestions?

Daniel
(Currently using 18-70DX kit and 70-300G)

PostPosted: Sun Apr 03, 2005 6:27 pm
by birddog114
So, do I pay more for the 1.4f, which looks like it is sharper but not very good built quality? Or should I go with the 1.8f that is cheaper, popular, but softer?


Welcome,
Where can you tell or show me the 50/1.4 is not with very good quality built? Have you seen or touch it physically? in both of the 50mm lens?

PostPosted: Sun Apr 03, 2005 6:38 pm
by DanielA
G'day,

Birddog114 wrote:Welcome,
Where can you tell or show me the 50/1.4 is not with very good quality built? Have you seen or touch it physically? in both of the 50mm lens?


No, I've haven't touched it. I was going from the page: http://www.kenrockwell.com/nikon/5014af.htm
Also the pictures I've seen show a plastic lens mount, is that correct?

I probably won't handle them until I would be making the final decision. I'd like to have a idea of things before I get to that stage. At the moment (based on the photo comparison) I'd probably go with the 1.4f, but was concerned about the comments about build quality.

Thanks

Daniel

PostPosted: Sun Apr 03, 2005 6:50 pm
by Aussie Dave
Hi Daniel
if you're happy with the quality of the kit lens, then the 50mm 1.8 should be fine. You're not really losing much in the way of f-stops, and as for sharpness, I've read that from mid f-stop upwards, the 1.8 is actually sharper than the 1.4.

Depends on who you believe really. If you've got the extra money to burn, get the 1.4, Otherwise, the 1.8 should be a great asset.

Just my opinion...

PostPosted: Sun Apr 03, 2005 6:57 pm
by stubbsy
Daniel

You might like to look at this thread

PostPosted: Sun Apr 03, 2005 7:09 pm
by birddog114
Daniel,
For the built of the 50/1.4, It's superb, solid, high quality built than the 50/1.8, and equal with the money which you're going to pay.

With the 50/1.4, which I have and love it with my shooting, of course what you pay what you get, not only that, among members in this forum, the number of people voted for 50/1.4 is always higher than 50/1.8.

PostPosted: Sun Apr 03, 2005 7:13 pm
by Killakoala
Ahah, I can help here.

I previously had the 1.8 and found it to be quite good. i have recently upgraded to the 1.4 and i find it better. Both lenses are made in Japan, however they are both made in China nowadays. You can still pick up Japanese made in either though.

This photo was shot WITH the 1.4
Image
I would suggest looking at the original which is here, to see how sharp it is.
http://killakoala.smugmug.com/photos/18300460-O.jpg

This pano was taken with the 1.8
Image

not a good comparison i know, but should give you some idea.

My points.
1. The 1.4 can do 1.8 and is sharper at 1.8 than the 1.8
2. The 1.4 is built better, no contest.
3. The 1.4 is twice the price for good reason.
4. The 1.4 has a really big hole through it, compared with the 1.8. It let's much more light in. When you see how much bigger, you will understand :)
5. The 1.8 is cheaper and still takes great, sharp pics.
6. The 1.8 is sharper than the kit lens.
7. The 1.8 can't do 1.4
8. Either 50mm will take good portraits.
9. The 1.4 has a rubber focus grip, the 1.8 is plastic.

I loved my 1.8 and was sorry to see it go, but i love my new 1.4 too.

Either choice, you will be happy.

PostPosted: Sun Apr 03, 2005 8:02 pm
by DanielA
Thank you all for the suggestions and references.

It does sound like the 1.4f is the way to go. I will search out a Japanese made 1.4f and let NAS kick in.

(fyi, another reference to the China made 1.4f: http://www.camerahobby.com/Review-50mm.htm)

Daniel

PostPosted: Sun Apr 03, 2005 8:13 pm
by birddog114
Daniel,
My 50/1.4 is made in China and it's brilliant same as other members.
I have lot of stuff made in China and they're working better than made in USA or Japan, price is half. :wink:

PostPosted: Sun Apr 03, 2005 9:12 pm
by fozzie

PostPosted: Sun Apr 03, 2005 9:20 pm
by DanielA
Birddog114 wrote:Daniel,
My 50/1.4 is made in China and it's brilliant same as other members.
I have lot of stuff made in China and they're working better than made in USA or Japan, price is half. :wink:


I'm interested why the Chinese made stuff is cheaper. Is Nikon passing on the savings in the cost of manufacturing?

Daniel

PostPosted: Sun Apr 03, 2005 9:22 pm
by birddog114
fozzie wrote:http://www.camerahobby.com/Review-50mm.htm


This article was at July 2000, and the guy who had the 50/1.4 just few hours and he did not have the completed test of the lens then wrote a review of it! funny :wink:

PostPosted: Sun Apr 03, 2005 9:41 pm
by birddog114
DanielA wrote:
Birddog114 wrote:Daniel,
My 50/1.4 is made in China and it's brilliant same as other members.
I have lot of stuff made in China and they're working better than made in USA or Japan, price is half. :wink:


I'm interested why the Chinese made stuff is cheaper. Is Nikon passing on the savings in the cost of manufacturing?

Daniel


Cheap labour in China and Thailand that why Nikon moved there, next one will be Vietnam, the most important we need is Genuine Nikon QC .
Nikon won't pass the saving in manufacturing to consumer, that is their bread and butter.

PostPosted: Sun Apr 03, 2005 9:51 pm
by DanielA
Birddog114 wrote:
DanielA wrote:
Birddog114 wrote:I have lot of stuff made in China and they're working better than made in USA or Japan, price is half. :wink:

I'm interested why the Chinese made stuff is cheaper. Is Nikon passing on the savings in the cost of manufacturing?

Nikon won't pass the saving in manufacturing to consumer, that is their bread and butter.

That's what I thought. I didn't understand why you said the "price is half." For us users of glass, I didn't think the price would change where ever it was made.

Thanks

Daniel

PostPosted: Sun Apr 03, 2005 9:54 pm
by birddog114
Daniel,
Pls. re-read my post.
I said I have lot of stuff (not glass) made in China and it's half price in comparison with the same product made in USA or Japan.
I didn't mentioned my glasses made in China is 1/2 price! :wink:

PostPosted: Sun Apr 03, 2005 10:02 pm
by DanielA
Birddog114 wrote:Pls. re-read my post.
I said I have lot of stuff (not glass) made in China and it's half price in comparison with the same product made in USA or Japan.

Ah, OK. I didn't read it like that.

Birddog114 wrote:I didn't mentioned my glasses made in China is 1/2 price! :wink:

It was worth checking. :D

Daniel

PostPosted: Sun Apr 03, 2005 10:09 pm
by Killakoala
HALF PRICE :shock:

When i visited Beijing back in ole '97, i happened upon Mao's tomb. The cost for local Chinese to enter and see his body was about 2 cents. For Westerners, it was 30 dollars US.

Suffice to say,
I did not pay,
For my way
On that day,
Hey!!!

:)

PostPosted: Sun Apr 03, 2005 10:14 pm
by birddog114
Why should people pay US$30.00 for a fake lying body of MAO?

PostPosted: Mon Apr 04, 2005 9:54 am
by Glen
DanielA, I have both, both very sharp (you would have to use test shots to tell the difference, not normal images), if low light is the reason you are purchasing, why sell yourself short? Get the 1.4 unless money is an option then get the excellent 1.8. You will be happy with either, but if you cant get the low light shot with your 1.8 you will always wonder would you have got it with the 1.4.

PostPosted: Mon Apr 04, 2005 3:30 pm
by Onyx
Killakoala wrote:Suffice to say,
I did not pay,
For my way
On that day,
Hey!!!

:)


Steve, considering a new career in the music recording industry? You rhyme better than 90% of the rap artists out there. ;)

PostPosted: Mon Apr 04, 2005 4:38 pm
by W00DY
Glen wrote:
but if you cant get the low light shot with your 1.8 you will always wonder would you have got it with the 1.4.



That's a good question though.

How much darker are we talking where the 1.8 wouldn't get the shot and the 1.4 would? And then how much darker until the 1.4 wouldn't get the shot?

Are we talking about a big difference or maybe just a small amount of light?

W00DY

PostPosted: Mon Apr 04, 2005 5:01 pm
by Glen
Woody, I don't have the difference in lux or lumen, but if we measure in f stops each extra stop lets in half the light or double going downward. The relevant stops here are f1.4 and f2.0. The 1.4 lets in double the light of the F2, or put another way the F2 lets in half the light of the F1.4.

The 1.8 is 1/3rd of a stop from F2 or 2/3 from f1.4. So I am guessing the f1.4 lets in 166% of the light of an f1.8

PostPosted: Mon Apr 04, 2005 5:09 pm
by MCWB
Yup, the 50 1.4 will let in 1.8^2/1.4^2 = ~65% more light at f/1.4 than the 50 1.8 @ f/1.8.

PostPosted: Mon Apr 04, 2005 5:14 pm
by Glen
Trent, can you come and do my maths exam? Pretty please :wink: Much better at algebra than me :wink:

PostPosted: Mon Apr 04, 2005 5:34 pm
by birddog114
Glen,
Trent will run a workshop on this soon! :shock: Compliments with Vietnamese food day at the mini meet. :wink:

PostPosted: Mon Apr 04, 2005 5:44 pm
by gstark
Glen wrote:Trent, can you come and do my maths exam? Pretty please :wink: Much better at algebra than me :wink:


2 + 2 = 5 (for vary large values of 2)

Woody, does 65% more light represent a great deal of difference? How long is a piece of string? How Long is actually a Chinaman, but that's another story, but I digress.

The real question really comes back to what does it take to get that shot.

Sometimes that 65% can be very significant, but it's all in the eye of the beholder.

PostPosted: Mon Apr 04, 2005 5:51 pm
by Greg B
Has someone got a lightmeter handy? (My Lunasix is at home, I'm in Perth)

Get the lightmeter, set it at 200 ASA (ISO), dial in f1.4, check required shutter speed; dial in f1.8, check required shutter speed.

OK, what are they?

PostPosted: Mon Apr 04, 2005 5:54 pm
by dooda
I think it depends on how dear the $350 or whatever the difference is. If it doesn't matter that much and you probably won't miss it, then you might as well go the 1.4; it's still a good deal, but if you will wonder what you could have done with the money, go the 1.8. They're both really fast.

PostPosted: Mon Apr 04, 2005 6:00 pm
by birddog114
dooda wrote:I think it depends on how dear the $350 or whatever the difference is. If it doesn't matter that much and you probably won't miss it, then you might as well go the 1.4; it's still a good deal, but if you will wonder what you could have done with the money, go the 1.8. They're both really fast.


Yeah! but not in the real low light with 1.8!

PostPosted: Mon Apr 04, 2005 6:03 pm
by Glen
Good thought Greg. Don't have a lightmeter, but luckily my D70 came equipped with one. On spot metering off a cream wall, at 1.4 the shutter speed was 1/125 or 1/160th of a sec, the 1.8 was 1/100th of sec, from a white lcd screen results were 1/320 and 1/250 sec respectively.




After reading GregB's post just added in details for F2, 1/60 or 1/80 for the wall, and 1/200 for the white LCD csreen.

PostPosted: Mon Apr 04, 2005 6:28 pm
by Greg B
Nice work Glen

One stop is a doubling of the light. f1.4 to f1.8 is one third of a stop I believe, so I imagine that if the 1.8 lets in an arbitrary 1 unit of light, the 1.4 would let in 1.33 units.

Glen's testing indicates that it might be slightly less.

PostPosted: Mon Apr 04, 2005 7:02 pm
by MCWB
Greg: f/1.4 to f/1.8 is around 3/4 of a stop.

The problem with that Glen's measurements is that they are only accurate to 1/3 of a stop. We're trying to measure a 3/4 stop difference in 1/3 stop increments, which isn't very satisfactory.

f/1.4 means 'aperture diameter = focal length/1.4', so for a 50 mm lens @ f/1.4, the aperture diameter is 50/1.4 = 35.7 mm. Similarly the aperture diameter at f/1.8 is 50/1.8 = 27.8 mm.

What we're really after isn't the diameter though, but the area that light can pass through (that's what determines the amount of light that gets in, hence the exposure). r = radius and d= diameter: Area = pi X r^2 = pi X (d/2)^2 = (pi X d^2)/4.

For 50 mm @ f/1.4, area1.4 = pi/4 X (50/1.4)^2 = 1001 square mm.
For 50 mm @ f/1.8, area1.8 = pi/4 X (50/1.8 )^2 = 606 square mm.

So (area1.4)/(area1.8 ) = 1001/606 = ~1.65, i.e. the area of the aperture hole @ f/1.4 is ~65% bigger. In terms of stops, this is log2(1.65) = 0.725 stops, or roughly 3/4 or a stop.

But that's all just a bit silly, because
(area1.4)/(area1.8 )
= (pi/4 X (50/1.4)^2) / (pi/4 X (50/1.8 )^2)
= (1/1.4)^2) / (1/1.8 )^2)
= (1.8^2) / (1.4^2)
= 1.65. :)

Note: 8 ) -> 8) is SO annoying when typing out a post like this. :roll:

Edited to remove incorrect assumption! :)

PostPosted: Mon Apr 04, 2005 7:18 pm
by Glen
Trent, can I please send any maths questions to you? Pretty please :wink:

PostPosted: Mon Apr 04, 2005 7:21 pm
by Greg B
Correct MCBW and others, the difference is 2/3 stop.

So my sentence should have read

One stop is a doubling of the light. f1.4 to f1.8 is two thirds of a stop I believe, so I imagine that if the 1.8 lets in an arbitrary 1 unit of light, the 1.4 would let in 1.65 units.

You might enjoy this page
http://www.uscoles.com/fstop.htm
called "A Tedious Explanation of the F-Stop"
which I found last time we had this same discussion about 1.4 v 1.8

cheers

PostPosted: Mon Apr 04, 2005 8:10 pm
by stubbsy
MCWB wrote:...Note: 8 ) -> 8) is SO annoying when typing out a post like this. :roll:

Trent when doing something like this you can use the Disable Smilies In This Post checkbox

PostPosted: Mon Apr 04, 2005 8:13 pm
by MCWB
Ouch, I've thoroughly confused myself.

Do people agree/disagree with that? Edit: I disagree! :P See below.

You're more than welcome to ask me questions Glen, but I may have to forward them on to my other half! :roll: :lol:

PostPosted: Mon Apr 04, 2005 8:23 pm
by Matt. K
Trent
You do all this by counting on your fingers! I've always held the belief that the difference between f1.4 and f1.8 is close enough to 1 stop. That is, for all practical purposes. I never let mathematics get in the way of what I instinctively feel is correct. :lol: :lol:

PostPosted: Mon Apr 04, 2005 9:07 pm
by MCWB
MCWB wrote:Ouch, I've thoroughly confused myself.

I agree! :roll: The correct formula should be this, as it's a logarithmic scale:
Number of stops difference = log2[(larger number squared)/(smaller number squared)]. Thank goodness for Excel, and good thinking time over dinner!

Thanks for that Peter, I'd forgotten about that function!

Matt: yup, for sure. I first realised my mistake when I was comparing f/4.5 to f/1.8. The area ratio is 6.25, but I know f/2 to f/4 is exactly 2 stops, so with a bit either side I thought it should be about 2.5 stops. Turns out log2(6.25) = 2.64, so I wasn't far off. Estimation (and/or experience) is always a good thing. :)

And just to get back on topic, log2[1/8^2/1.4^2] = 0.725, so nearly 3/4 of a stop from f/1.4 to f/1.8.