afd 28mm f1.4 vs afd 50mm f1.4 question

[hugh_t]

This could be (and I apologize in advance if it is) an incredibly

stupid question. The 28 1.4 afd costs @1400 usd and the 50mm 1.4 afd

costs @250 usd. I realize that the 50mm lens is one of the easiest to

manufacture but why does the 28 mm cost almost 6 times more?? Can you

shoot in lower light with the 28mm because of the shorter focal

length?? Or is there something else I'm missing? Just curious. Thanks

in advance for any insights.

[ilkka_nissila]

I believe the 28/1.4 has a precision-ground aspherical element, which makes it expensive.

[hugh_t]

Thanks for the answer, I'm not doubting you but that makes a 1200 difference??

[todd peach seattle, washi]

It's a little understood phenomenon, but Nikon has a 'carat weight' cost escalation in their pricing; the heavier it is, the more it costs (OK, just kidding).

 

I believe the 50mm f/1.4 has had a substantially unchanged optical design from the mid-70's. This expands a little on your 'easiest to manufacture' point; the optical R&D is spread across a much larger number of fielded units.

 

Of course by that logic we should have seen a $300 105mm f/2.5 AFD by now.......

[hugh_t]

Does the opening of 1.4 mean the same on the 50 and the 28 or is it wider on the 28 because of the shorter focal length??? If the opening has to be larger on the 28 (to achieve the same 1.4) that would explain alot.

[todd peach seattle, washi]

<i>

Does the opening of 1.4 mean the same on the 50 and the 28 or is it wider on the 28 because of the shorter focal length??? If the opening has to

be larger on the 28 (to achieve the same 1.4) that would explain alot.</i>

<p>

Actually, it's the other way 'round (sorry). Theoretically, a 50mm f/1.4 lens needs a 36mm diameter (50/1.4) vs the 28mm f/1.4 needing only 20mm (28/1.4).

[ilkka_nissila]

Yes, that makes the difference. It's the same thing with those 35 mm f/1.4 Leica-M aspherical lenses, they cost even more and for the same reason.

 

I'm obviously not an expert in optics manufacturing technology, but ... basically grinding is the most precise way of manufacturing things from glass. The reason most elements are spherical is that they can be ground easily. Aspherical lenses can be made in different ways, to different quality standards. The surface quality and required tolerances from the optimal shape, and material choice(sometimes plastic is used as part of aspherical elements) all affect the way light is bent by the element. Highest quality surfaces can be made by numerically controlled grinding machines. I believe the problem is that numerical grinding to the required tolerances is extremily time-consuming and the instrument that does it is also very expensive.

[ilkka_nissila]

In practice the diameters of the front elements of wide angles are quite large due to the relatively large number of elements in the lens (retrofocus design + CRC etc.). The lens is quite long and the wide angle of view of the 28 mm thus requires a large front element.

 

If anyone is unhappy with their 28 mm f/1.4 AF Nikkor, I would be willing to give a home to one ... ;-)

[klix]

Hugh - The aperture size(as), focal length (fl), f-stop(fs) formula is as = fl/fs (exactly what Todd wrote) -- this is an optical constant = the longer the lens, the wider the lens diameter for any given f-stop. I don't think this is where the $1.4k comes from...

 

It's the manufacturing cost -- apparently, the 28mm f1.4 uses <b>precision ground-glass</b> aspherical lens elements minimizes distortion and coma (per Nikon) -- I believe this is where the majority of that $1.4k comes from.

[jim_gifford]

<<Can you shoot in lower light with the 28mm because of the shorter focal length?? >>

 

Yes and no. The two lenses would offer you the same shutter speeds in the same lighting conditions, so in that sense there's no advantage between the lenses. However, most folks feel they can get acceptably sharp hand-held shots at slower shutter speeds using wide-angle lenses.

 

The rough rule of thumb is the shutter speed should be no slower than the reciprocal of the focal length, so you want 1/250 sec when using a 200mm lens, 1/60 sec when using a 50mm "normal" lens and 1/30 sec when using a 28mm lens. If that rule of thumb works for you, a 28mm lens becomes "one stop faster" than a 50mm lens in any given lighting situation because you can use a longer shutter speed.

 

Are your hands reasonably steady? In practice, and with good technique, you can have pretty good results shooting at shutter speeds much slower than the "reciprocal of focal length" rule would suggest. I have a nice picture of the "world's longest ribbon stalactite" inside Smoke Hole Caverns in West Virginia... It was taken handheld with the Nikkor 50mm f/1.4 lens at about 1/4 second in the available, ahem, light for tours of the caverns. But whenever I squeeeeze that shutter for a 1/4 second handheld shot, I have to tell myself there's only a fair-to-poor chance the results will be worth keeping.

 

Hope that helps.

 

Have fun,

[scott_warn]

A couple of points that I would like to add to the above..................................................................

 

1) The 28mm f1.4 is an very low volume lens. Lower volumes means

that the R & D costs are spread over a much smaller number. It

also means that the lens is bench assembled by hand, the volume

is not high enough to justify the cost of building an automated

production line.

 

2) Retrofocus wide angle lenses present an optical challenge and a

very fast lens such as the 28mm f1.4 probably requires hand

selection of elements and precision hand assembly on an optical

bench. It would not surprize me if this lens were assembled in

Nikon's R & D lab by lab technicians.

 

3) The 50mm f1.4 is a high volume lens that has been produced

without change for ages. It is probably produced on an fully

automated production line with the only human input being

the quality control checks.

[armando_roldan]

Get the 50mm f1.4 instead of the 28mm f1.4

 

You just have to stand back further to get the same image. And take the $1150 you saved a buy a new F100 camera.

[klix]

Armando -- I realize you're just being facetious, but sorry, NO -- you do NOT get the same image the you would on a 28mm f1.4 by just taking a few steps back with your 50mm f1.4... Setting aside the difference in lens construction, you would not be able to handhold your 50mm in lighting situations that would demand a wide open 28mm.

 

Sorry but IMHO -- handheld, only way you'd match the 28mm f1.4 in extremely poor lighting is to use an RF.

[angel_o.]

IMHO, the only reason that would justify a 6 times higher production cost is that the 28/1.4 is an very low volume lens. If the US$ 1400 or even the US$ 250 are justified? I doubt it. <br><br>In Europe the production and R&D costs want to justify EUR 2.849,00 vs EUR 409,- for these lenses - it's 2x vs 1.6x the US price, though the normal income is about the same as in the US (if not less)!

[dan_andrews]

Armando, the 28mm field of view is just a tad different from the 50mm field of view. Perhaps you've noticed?

 

About costs in Europe: Camera gear is much much much more expensive in Europe for a lot of reasons. There are so many that it should probably be a separate thread. That said, I know of a number of people who got a cheap ticket to New York from Europe, bought a camera and lens (or several!) at US prices, and STILL paid less money than if they bought the camera in the UK, France, or Germany.

 

Nikon lenses are especially expensive in Europe, though some of the Nikon bodies aren't too much more.

[duncan_mcmorrin2]

Dan, that's true but with Nikon's current warranty issues, well...we end all the way back at that "can I get my new USA D100 serviced here in Europe?" thread...:-)

 

Cheers, Duncan

[ilkka_nissila]

Yes, sure you can get things cheap in the US, but if the thing has a problem, you can have it warranty serviced within the first year provided you get the US version(if exported, the 5-year extended warranty is not effective). But that one year is not much considering that I've never had to pay for Nikon's service (even with old gear). I hear that in the US, if you have an out-of-warranty item, you essentially pay $200 for every little thing that they do to it. Not so in my country. Essentially, ultimately, you get what you pay for (or at least close to).

[larry n.]

Someone said "You just have to stand back further to get the same image."

 

I hate to be rude, but that's rubbish. When you stand back further you get a different perspective, a different picture.

 

As a number of people said, the 28/1.4D has an aspherical precision ground element. I believe it's the only Nikon to have such an element, and that's why it's the most expensive lens Nikon makes (other than the 300/2.8 and bigger lenses). It's a also a low-volume lens, indicating that not many shooters have a use for it.

 

Is it worth the money? I'm not sure you can compare it to the 50/1.4 because they have a different focal length. I have both lenses and it's very hard to confuse them. In other words, I use them to accomplish very different tasks.

[ilkka_nissila]

The older AF 20-35/2.8 had also a ground aspherical element, and that's why it was just as expensive as the current 17-35/2.8 AF-S. The latter has the AF-S motor, ED elements and (other types of)aspherics, so you can pretty much say that the ground aspheric doubles the price of the lens.