New Zeiss M-lenses

[plexi]

Camera-info.com - Canon, Nikon, Sony, Minolta, Olympus, Contax, Leica Forum, Photo Gallery, Interviews, Reviews etc. - New Zeiss lenses for Nikon, Hasselblad and Zeiss Ikon/ Leica M

[plexi]

Damn, that link came out weird, but just click on the text...

[albertwang]

Okay, I'm definitely checking out the Zeiss ZF lenses.

Looks like a good fit to my Nikon stuff. Sexy!

[FastFashnReloaded]

What do you have to do to make the MF Zeiss/Nikon lenses work on ... let's say... a D-80? WILL they work without it taking a minute per shot to set up, meter, focus and shoot?

[albertwang]

Sorry but the D80 won't meter with the ZF lenses directly. You basically shoot, look at histogram, and then reshoot (actually this is better because it forces you to think about the shooting process itself)...

If you want matrix metering or metering at all use a D1, D2X, D200, D1X, etc. Any body with the little tab for metering (D70 and D50 and D80 doesn't have this)...

But at least you get electronic rangefinder in ALL bodies! That's more important for me with Nikon + ZF combo.

[supperman]

Yeah, especially if you don't have a full frame viewfinder to manual focus with

But back to the ZM lenses, I think it's interesting that Zeiss has introduced these lenses in the light of the Leica 16-21mm Tri-Elmar. I still need a 21mm lens for the 28mm FOV on the M8, so people in my shoes will have to decide if we would go for the Leica 21mm Asph, Tri-Elmar, or the Zeiss 21mm f/2.8 or the f/4.5. Both the new ZM 18mm a 21mm lenses will probably be much cheaper and smaller, perfect for travel, while the Tri-Elmar is going to be a lot more expensive and much larger.

Urgh! Decisions decisions!

[MP3]

I have post a similar thread on Digital Forum as well. One of my prime focal length is 28mm. Having considered all the mentioned options, in terms of image qualities, lens pricing, f-stop, from Leica to Zeiss. I believe, at this moment, I will go for the ZM 21 2.8 Biogon and my current Leica 28 finder for the coming M8. Just my 2 cents.

Best
Matthew

[grober]

OK, a new 18 and 21 in the M mount. Again: f4 (or 4.5) is TOO SLOW for a handheld rf camera such as the Leica M or Zeiss Z1.

What is Zeiss thinking here?

(Maybe I should wait until the pricing is announced. I do own, use and adore the ZM 25/2.8 Biogon.)

Hey Carl, where's your Z-digital camera?

[albertwang]

Zeiss was thinking about portability when they designed the f4 lenses. If you think that's too slow, why not raise your ISO?

Oops, I forget, perhaps you can't find the button eh?

[palaeoboy]

"OK, a new 18 and 21 in the M mount. Again: f4 (or 4.5) is TOO SLOW for a handheld rf camera such as the Leica M or Zeiss Z1.

What is Zeiss thinking here?"

Given that they have a faster 21 already then its fairly easy to believe that they are covering all markets. A 21 is not as commonly used focal length as some others like 50 and 35 and a less expensive slower 21 certainly has a market, the Voigtlander 21 f4 has shown that.

The 18 is no slower than the tri-elmar and these are the only offerings for M mount in the 18mm focal length. As for being too slow for handheld RF photography, they are very wide lenses that can be handheld at much slower speeds. For this reason I prefer smaller than faster. If they get too large for a focal length that I dont use that much I would probably leave it at home alot of the time. I believe thats possibly what Zeiss was thinking.

[albertwang]

Indeed, it's better to create lenses that are going to be useable in the field. A 18mm f2.8 would be nice but it has a 86mm filter thread, no one is going to want to carry that everywhere (see complaints about Noct size). And one knows that faster wide angles mean larger filters because the lens needs to capture more light at a wider angle.

[stunsworth]

[quote=albertwang And one knows that faster wide angles mean larger filters because the lens needs to capture more light at a wider angle. [/quote]

So why does a 50mm Summicron have a smaller filter size than a 90mm one?

[doubice]

Originally Posted by stunsworth

So why does a 50mm Summicron have a smaller filter size than a 90mm one?

50mm : 2 = 25mm
90mm : 2 = 45mm
180mm : 2.8 = 64mm

Diameter of the diaphragm opening at full aperture determines the size of the front element.

Jan

[stunsworth]

I know Jan, I was just pointing out yet another of Alfie's little errors.

I imagine, and I'm not a lens designer, that the front elements on wide angle lenses get bigger in order to correct abberations, nothing to do with capturing more light.

[albertwang]

I thought that abberrations were corrected by the use of aspherics?

The wide angles still need to be with larger front elements... for example,

a faster 21mm f2.8 will always need a larger filter than a 21mm f4.

You can't compare across different focal lengths.

Look at the 50mm M-lenses

The filter diameters goes as follows:

50mm Elmar-M < 50mm Summicron-M < 50mm Summilux-M < 50mm Noctilux...

Okay, I think that this brings a valid point.

I doubt that the front element alone is sufficient to correct aberrations. It is typically a middle element that allows for the full correction of how the image is formed. (although I do believe that the 35mm aspheric M-lenses are an exception?)

[stunsworth]

Sorry, I didn't realise you were talking about faster within a single focal length.

Correcting abberations isn't just done by asherical surfaces.

[doubice]

Main reason for larger front element size of all wideangle lenses is that most are retrofocus types. A true wideangle lens’ (non-retrofocus) rear element is positioned very close to the film plane; this was fine with non-metered Leicas in the past. With the introduction of the M5, CL, M6 etc, the rear element prevented light from hitting the metering spot on the curtain or prevented the meter arm of the M5 and CL to rise altogether.

Compare the size of the front element of the following M mount lenses: Super Angulon 4/21mm, Super Angulon 3.4/21mm and the latest 2.8/21mm. At the same time, see how much the original Super Angulons protruded into the camera body.

Simply explained (and I mean a real simple explanation….) - retrofocus wideangle lenses are reversed telephotos; try looking into a pair of binoculars from the wrong end, that is the effect. All of today’s Leica M and R wideangles are retrofocus, with the R ones being a full retrofocus design, while the M lenses could I guess be call a mild retrofocus. On an SLR, the rear of the lens has to clear the mirror, thus the need for a full retrofocus design.

All the best,

Jan

[albertwang]

Jan, you're right.

Plus one needs to remember that the underlying philosophy of Zeiss is to keep the optical formulae symmetrical across the mid axis. When you look at the optical diagrams of Distagon, Sonnar, and Planar one can see how much Zeiss tries to stick to this.

Leica has a different philosophy but I don't think that it is based on the optical configuration (at least I fail to see a pattern among the optical diagrams in Puts' book).

[albertwang]

Originally Posted by stunsworth

Correcting abberations isn't just done by asherical surfaces.

You're correct. In fact, chromatic abberration can occur due to sharp angle against a digital sensor (which is why 4/3 is all telecentric) or shooting wide open (Leica is emphatic to correct this first!).

Typically telephotos will suffer from the color fringing which is why the APO designation is needed to show that this problem is solved.

[MP3]

Originally Posted by doubice

50mm : 2 = 25mm
90mm : 2 = 45mm
180mm : 2.8 = 64mm

Diameter of the diaphragm opening at full aperture determines the size of the front element.

Jan

Hi Dear

Just curious and want to enrich my optical knowledge,
by the same principal, then:

28mm: f2 = 14mm
15mm: f2 = 7.5mm

what is the another factor that make these large aperture WA big lenses?

Best
Matthew