Voigtländer 25mm F0.95 "Nokton" for micro-4/3

rawhead · Expire: 2014-04-29

Personally, this was the big news of the day (nothing from Canon was exciting Laughing

).

http://www.43rumors.com/the-new-voigtlander-25mm-f0-95-for-microfourthirds-has-been-announced/

I'm about 60% sure I'll buy this (by selling my Macro-Switar 26/1.1 to fund it).

poilu · Expire: 2019-08-29

that's great news
m4:3 users will now have the equivalent of a 50:2.8 on full frame
the canon 50:1.8 sell for 100 euros, I hope this one will be about the same price

ylyad · Expire: 2013-12-05

I understand the equivalence on focal lenght, but why multiplying the aperture? I think it's not required to. It's equivalent to a 50mm f/0.95.

And it's MF, and it costs 900 USD...

poilu · Expire: 2019-08-29

no-X · Posted: Thu Aug 26, 2010 9:19 am Post subject:

Poilu, that's true for DOF, but it isn't true with light. The amount of light is still the same. You won't get neither overexposed nor underexposed image when using full-frame lens on 4/3 camera. The camera just makes crop of the central part of the image. The image will be less wide, nothing more. Just like you can use Pentacon Six lenses on Praktica without any exposure corrections.

Small format cameras only crops the image, nothing more.

//edit: lenses for larger format cameras captures more light, yes, but this additional light is used to draw the wider image circle, not to bring more light to the center of the circle... lens speed is constant unit, it isn't affected by format... every f/2.8 lens will project the same amount of light per unit of area (e.g. mm²)

poilu · Expire: 2019-08-29

kds315* · Expire: 2021-03-09

(c) Cosina

I may be lusting too for that one...

ylyad · Expire: 2013-12-05

Aperture is fixed and depends on the lens. A 50mm 1.8 on FF is equivalent to 80mm 1.8 on APS-C.

I don't understand what it has to do with ISO, sorry. I understand the relationship on DoF and captor size. I understand the magnification need (i.e. an APS-C image will require more magnification than a FF to be printed, let's say on a 10x15 picture) and I understand the consequence on noise (i.e. as the APS-C image requires more magnification, it will have more noise comamred to the FF, comparable with a higher ISO setting on FF).
But the link between ISO and aperture, I don't see it...

no-X · Posted: Thu Aug 26, 2010 10:34 am Post subject:

WolverineX · Posted: Thu Aug 26, 2010 10:41 am Post subject:

just to get into the whole puzzle about using larger format lens on smaller sensor and whole light thing...(and get my ass kicked Wink

) doesn't it play the part at what distance is iris from the sensor? Iris, with same aperture set, at different distances from the sensor lets different amount of light through. so you have to look at that too when comparing lenses, for example i compared P6 flektogon 50mm iris distance with m42 regular 50mm lens and at the same aperture mark flektogon had bigger opening of the iris, so wouldn't that give more light and more speed to flektogon on smaller sensor?

crude drawings of different distances of iris set at the same value from sensor , and light going through

and two sizes of sensor compared at the same aperture at the same distance

be gentle while kicking my ass over this Wink

poilu · Expire: 2019-08-29

bogolisk · Expire: 2011-11-18

no-X · Posted: Thu Aug 26, 2010 11:16 am Post subject:

Using the same ISO settings, every f/2 lens will result in the same exposure on every camera. But poilu is trying to describe a situation, which would result in similar FOV, DOF and exposure time.

poilu · Expire: 2019-08-29

ManualFocus-G · Expire: 2014-11-24

I see the same exposure time on both APS-C and full frame cameas with the same lens...BUT...I can shoot a 50mm lens at 1/50th second for a sharp image on full frame, but need 1/80th second on crop. I always presumed this is nothing to do with aperture and everything to do with the effective focal length and the loose rule that you should shoot at a minimum speed equal to the focal length e.g. 50mm = 1/50th second on ff.

ManualFocus-G · Expire: 2014-11-24

Poilu, if that's the case, why have Canon, Nikon, Sony etc. never produced faster lenses for APS-C?

kds315* · Expire: 2021-03-09

Gosh, not AGAIN that same discussion...

Guys, read http://www.zeiss.com/c12567a8003b8b6f/embedtitelintern/cln_35_bokeh_en/$file/cln35_bokeh_en.pdf, even better UNDERSTAND it (#4 and #5 onwards)

SIGHHH...

poilu · Expire: 2019-08-29

ManualFocus-G · Expire: 2014-11-24

Klaus, I will need a while weekend to get through that Laughing

Early indications are that depth of field wise, there is a difference on a crop camera (much like the cropped focal length) and this makes perfect sense. But I haven't got to the bit about whether this affects exposure Wink

bogolisk · Expire: 2011-11-18

rawhead · Expire: 2014-04-29

no-X · Posted: Thu Aug 26, 2010 2:00 pm Post subject:

bogolisk: Imagine a situation:

You have a FF camera with 50/2 lens. And you are trying to find a 4/3 solution, which would give you similar characteristics as the FF system.

So you must solve 3 issues:

1. depth of field
2. field of view
3. exposure

With 50/2 lens on 4/3 system you would have much narrower field of view (comparable to 100mm lens), so you should move further from the subject to fit it in the shot. Solution would be to replace the 50/2 lens by 25/2 lens. Both 50mm lens from double distance and 25mm lens from the same distance would result in similar field of view, but depth of field would be still different compared to the FF system. With the 50mm lens it would be higher due the bigger distance from the object, with the 25mm lens it would be higher (too) because of the wider focal length. Solution would be a faster lens, 25/1.0.

Now we would have the same field of view, the same bokeh (or depth of field), but this f/1.0 lens would give us differens exposure than f/2 lens on FF system. If we prefer to use same exposure time, it would be easiest to use less sensitive ISO settings on the 4/3 camera, e.g. ISO 100 instead of ISO 400.

Crop cameras are mostly noisier, so poilu presumes, that ISO 100 on 4/3 camera would be comparable in terms of noise with ISO 400 on full-frame camera.

bogolisk · Expire: 2011-11-18

rawhead · Expire: 2014-04-29

The mathematics of ISO performance/dof/fov is sound; but the overall tone is not.

We're not talking about standing in front of your arsenal and saying "Hmm, I'm shooting a wedding today, which one of these will give me the best persormance", in which case a FF camera + 50/1.4 (or, even better, a Mamiya MF digital cam w/ 80/1.9) will be a better choice.

However, like someone once said, the best camera is the one you have with you; unless you are committed to always carrying around that 5D + 50/1.4 (or MF digital camera), I am going to trump you with my GF1 + Nokton 25/0.95 one day, because you'll only have your cellphone cam to shoot the same subject Smile

Some people have that commitment, and I praise them. I'm actually pretty similar, though these days, I tend to go for MF film camera than 5D. But some days, I just don't want to bother with any of that, so I just grab my GF1 + Macro-Switar 26/1.1 and I'm golden.

As for what it should cost, it's silly to suggest it should cost the same as a Canon 50/1.8, because the quality of the picture is not dependent solely on the lens, but on the full package. I.e., the 50/1.8 has to be combined with a $2200 FF DSLR to give you the same quality shot as this 25/0.95 on a m4/3. In order for these two to be comparble, the 25/0.95 could be $1800 and still it'll be cheaper than the 5D + 50/1.8 combo Smile

Or, you can do a comparison of weight/size, too. A GF1 + Nokton will be around 780g (still a bit heavy if you ask me). In order for a 5D (940g) to compete with that, the 50/1.8 will have to be -160g Laughing

Also, the Nokton's closest focusing distance is 17cm (Canon 50/1.8 is 45cm). I think we'll also need to purchase some extension rings for the 50/1.8 to make it more comparable Smile

Once all that's been put on a level playing field, *then* we can talk about the level of craftsmanship, technology, optical performance, etc. and decide what the appropriate price is for the lens. After all, I think we can all agree that, say, a Contax/Zeiss 50/1.7 doesn't have to be priced the same as a Pentacon 50/1.8 just because they have comparable fov/dof/effective speed Smile

poilu · Expire: 2019-08-29