Some mirrorless options for Pentax

Started Aug 25, 2018 | Discussions thread
Barry Pearson
OP Barry Pearson Veteran Member • Posts: 8,723
Re: Some mirrorless options for Pentax

Fogel70 wrote:

Barry Pearson wrote:

Fogel70 wrote:

Barry Pearson wrote:

Fogel70 wrote:

.... There are many points of making a new mount as a short register distance mount have to be designed differently to best support short register distance lenses. A larger mount would be better as short register distance lenses have large rear lens elements. K-mount is not large enough for this.

See my post above:
https://www.dpreview.com/forums/post/61554148

I believe a lens with rear elements of about 30mm diameter could fit within the body of a mirrorless K-mount camera. That is quite a substantial proportion of the 44mm image circle of an FF lens.

It is not only the rear lens element that would habe to be fitted inside the protruding tube. Several lens elements with lens fittings and focus mechanism would have to be fitted inside which will limit the image circle to less tham 30 mm.

Did you really mean "image circle" in that statement?
Not "rear element diameter"?

I ment to say that I the projection of the image circle may use 25mm of the 30mm rear element.

Ideally a rear element very close to the sensor would have to cover the whole image circle so the the light hit the sensor in a straight angle. I believe this is what Nikon has planned with the new Z mount.

Are Nikon intending to have a rear element for their ultra-wide lenses of 44mm diameter, which is the FF image circle diameter? (Or 1.7 inches in old money?)

I'm not saying thst Nikon will use 44mm rear element on every lens they design, but they do not want the new mount to limit lens design for now and the future.

Wouldn't it be nice if Ricoh/Pentax had the resources that Nikon has, to try to be technically pretty-well future proof?

I wonder what the total design and development cost for the new mount has been for Nikon? (Compared with the resources available for Pentax development).

It might not only be used for wide angle lenses, normal an tele lenses can benefit from that too.

Ricoh/Pentax appears to have at most sufficient resources to develop 3 lenses a year. And lately they haven't achieved that.

As far as I can tell, lenses for Q-mount are on hold. (Or terminated for ever?)

Lenses for 645 appear to be in the doldrums.

So the rest is split between K-mount APS-C and K-mount FF, with the emphasis being on FF recently.

If there is another APS-C flagship, I suspect that Pentax will want a lens or two to announce at the same time. And there are 6 FF lenses on the roadmap, plus potentially an FF 1.4x Rear Converter.

I believe that, whether or not Pentax introduce a mirrorless camera over the next couple of years, every new lens for a few years will have to be fully compatible with the current Pentax SLRs, unless there is simply no choice. And so far, for longer lenses, there is a choice - don't attempt large apertures on such lenses.

Or perhaps an alternative is "only attempt long large aperture lenses for APS-C". Would that be easier to achieve? Lens design problems appear to scale up rapidly with increasing sensor size.

I suspect this is a case of "if Pentax wants to get to where Nikon are going, they mustn't start from where they are"!

I would like to see evidence for that!

Yes it will be interesting on how the lens formula will look on Nikon Z lenses. Especially the 58/0.95.

Yes, that lens fascinates me! (Manual focus, too).

 Barry Pearson's gear list:Barry Pearson's gear list
Ricoh WG-6 Panasonic LX100 Ricoh GR III Pentax K-7 Pentax K-3 II +27 more
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