1bwana1
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 Re: Really dislike the size of these lenses | |
Steve Spencer wrote:
1bwana1 wrote:
az-dave wrote:
When I compare the size of the 50mm 1.8G against the 50mm 1.8Z it looks like the 1.8Z has a built in FTZ adaptor to keep the lens the same distance from the sensor.
Because of the very large Z-Mount flange diameter, I think lenses for the Z-Mount will pretty much always be larger and heavier than that the same lens design for small flange diameter mounts like the Sony E-Mount. If what is desired is the smallest, lightest, lens of a particular optical performance, the Z-Mount has designed itself into sort of a corner.
Let's use the excellent Voigtlander line of lenses as an example of this. Voigtlander is a good comparison tool because it has made the exact same optical design lenses for both E-Mount and Z-Mount. Many of the lenses were direct ports over to the Z-Mount from the E-Mount (or M-Mount) counterparts. For these you will see the added diameter weight and size embodied in what looks to be a built in adapter as you noticed in your Nikon 50mm 1.8G example.
Sony E-Mount versions: https://www.voigtlaender.de/lenses/e-mount/?lang=en
Nikon Z-Mount versions: https://www.voigtlaender.de/z-mount/?lang=en
For those lenses with optical designs that already exceed the diameter of the Z-Mount, you will see the full body without what appears to be an adapter. But, those lenses are also significantly larger that their E-Mount counterpart. Let's take the very good Voigtlander NOKTON 50mm F1.2 Aspherical as an example. It is significantly larger and heavier.
E-Mount Version Length = 58.8mm Diameter = 70.1mm Weight 434 grams
https://www.voigtlaender.de/lenses/e-mount/50-mm-112-nokton-e/?lang=en
Z-Mount Version Length = 66.6 mm Diameter = 70.1mm Weight = 598 grams
https://www.voigtlaender.de/z-mount/50-mm-11-0-nokton/?lang=en
It seems to me that if size and weight are primary criteria for selecting a camera system the the Z-Mount may not be your first choice. This seems to be true even if the same levels of optical performance are desired.
Steve, you are comparing the Sony 50 f/1.2 vs the Nikon Z 50 f/1.0 lens. Of course the Nikon lens is bigger; it is half a stop faster. The better comparison is the 40 f/1.2 Asph as it exists in both mounts:
Sony E mount SE version: diameter 66.5 mm; length 51.9mm; weight 340g
Nikon Z mount version: diameter 67.7mm; length 53.9mm; weight 315g
Although not identical the Nikon Z mount version seems to be about the same size and the Sony E mount SE version. The non-SE version of the E-mount lens is bigger than the Z mount in every dimension. Sony E mount non-SE version: diameter 70.1mm; length 59.3mm; weight 420g
I don't think the Voigtlander lenses suggest at all that Nikon Z mount lenses are going to be bigger than Sony E-mount lenses.
So I have had time now to correctly look at the Voigtlander lenses more closely in relation to the large diameter flange. Here is what it looks like to me. As long a lens designer uses the same design and diameter for the optical components of a lens, the larger Z mount doesn't require a larger and heaver lens to be built. This looks to be because the FF sensor is the same size in all the mounts, so the lens image circle can cover it the same way. Makes sense. So the only requirement is that a larger mount and spacer must be included in the barrel design to properly mount the optics. In this view the larger Z-Mount can be seen as providing more options to the designer, and he is free to choose different approaches. A definite plus for the Z-Mount.
Thanks to Steve Spenser again for catching my error with the 50mm Noktons. I was paying attention to the name and lens form factor, not the aperture number which of course made it a non valid comparison.
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