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Over half of Pentax FF-compatible lense output is wasted on APSC

Started Sep 23, 2014 | Discussions
KL Matt Veteran Member • Posts: 5,999
Over half of Pentax FF-compatible lense output is wasted on APSC
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So those full-frame compatible K-mount lenses we purchased, they are actually capable of putting out 2.5 times more light and detail than our APSC Pentax bodies can make use of. The rest is simply discarded by the camera body -- sucked up by the black surfaces in the mirror box. Wasted. It might not be exactly 2.5x the detail in lpm or even light once you account for sharpness falling off towards the edges and light fall off, but it would be close for most lenses.

So the advantage of FF is to shoot in half the light, and while you're doing it, get more than double the resolving power for a given pixel density. If a Pentax full frame body comes out that is not considerably larger than the k3, you'll have very little size drawback, particularly on the telephoto end of things, where most of the lenses are already FF compatible or close to it.

That's why FF would be a great thing for K-mount. It would give the K-mount back its title as the system with the best "power-to-bulk ratio" in the world. They maintained that title over decades in the film era on through the Pentax *ist D-series in digital but gave it up rather arbitrarily with the much bulkier k10d. When they decided they wanted it back, it was too late, mirrorless had usurped them on the small end of the APS-C spectrum. The only way to get back home again with the K-mount now is with a FF.

Here's to hoping it will be a K3-level body with nearly identical ergonomics and features, perhaps without the fast frame rate. Having a ff and crop body in my kit would eliminate the need for a teleconverter while at the same time allowing me to shoot events with two bodies - a fast wide like mz FA* 24 on the full frame and a fast 50/55 or my FA 43 on the crop body. Wouldn't it be fantastic to have the flexibility to also swap bodies to get a different effective focal length instead of swapping lenses? Every single FF lens you had would be like two lenses in one. My FA 77 would certainly gain a new life, as would the 31.

If Pentax makes a FF that's 100% compatible with all their lenses and makes it easy to switch back and forth, they're going to have a unique selling proposition when I hear about the difficulties in this respect with other systems.

Matt

... interested in .... photographs? Heh? Know what a mean? Photographs? (He asked him knowingly). Nudge nudge, snap snap, grin grin, wink wink, say no more, say no more, know what a' mean? Know what a' mean?
http://www.pentaxphotogallery.com/home#section=ARTIST&subSection=183820&subSubSection=0&language=EN

Pentax *ist D Pentax K10D Pentax K-m (K2000)
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robbo d Veteran Member • Posts: 3,884
Re: Over half of Pentax FF-compatible lense output is wasted on APSC

........ I'm hearing ya. 

Have just received an F 70 - 210 and an F 35-70 coming with an FA 28-105 already, plus a couple of 50mm's , whilst not stunning lenses, it does give an almost two system in one capability with familiar menus etc. Major bonus.

Any future kit I would then consider wether I purchased aps-c or FF to do both but we have options.

OP KL Matt Veteran Member • Posts: 5,999
Re: Over half of Pentax FF-compatible lense output is wasted on APSC

whilst not stunning lenses, it does give an almost two system in one capability with familiar menus etc. Major bonus.

Yep. Let's hope Ricoh/Pentax picks up on that and exploits it for al its worth. I don't think the other brands are doing that.

Compatibility has long been a K-mount selling point. This is one way to really capitalize on that.

Matt

Bmoon Regular Member • Posts: 291
Re: Over half of Pentax FF-compatible lense output is wasted on APSC

For the longest time my only wish was for pentax to exploit the full potential of the K mount.

Now we are at the tipping point at which pentax can do so in the next year with an affordable camera My only hope is that pentax can see this and make things happen before their main user base have left. Without this user base pentax will have to compete head to head with well-established FF systems of other brands for new customers to make up for the converts. Can pentax compete on the path they have set forth without a FF?

 Bmoon's gear list:Bmoon's gear list
Canon EOS 5D Mark II Pentax K10D Nikon D3X Nikon D300S Pentax K-5 +7 more
robbo d Veteran Member • Posts: 3,884
Re: Over half of Pentax FF-compatible lense output is wasted on APSC

Bmoon wrote:

For the longest time my only wish was for pentax to exploit the full potential of the K mount.

Now we are at the tipping point at which pentax can do so in the next year with an affordable camera My only hope is that pentax can see this and make things happen before their main user base have left. Without this user base pentax will have to compete head to head with well-established FF systems of other brands for new customers to make up for the converts. Can pentax compete on the path they have set forth without a FF?

I think that FF will become ... in the foreseeable future ..... another significant string in Ricoh's bow. So it will very much help them compete. Albeit if only the forecast numbers predicted aren't big, like the 645Z, have a minimal production run and find yourself having to re order more because of the demand ...... at least then your covering another market, will regain some of your old faithful an a handful of converts, plus a fair bit more kudos in the market.

General public will start seeing Pentax's at tennis matches with 400mm lenses on and at weddings and so it begins. Then have the entry level and new image stuff like K-S1 which will entice the up and comers.

It is logical with the k mount and as mentioned above just makes for so much practicality to be able to utilise lenses on both sets of bodies giving you what you need at any given requirement. Ultimate landscape quality or low light performance, use the FF body, then when your birding and want the reach, grab the K3 body....

The Davinator
The Davinator Forum Pro • Posts: 24,707
Re: Over half of Pentax FF-compatible lense output is wasted on APSC

robbo d wrote:

Bmoon wrote:

For the longest time my only wish was for pentax to exploit the full potential of the K mount.

Now we are at the tipping point at which pentax can do so in the next year with an affordable camera My only hope is that pentax can see this and make things happen before their main user base have left. Without this user base pentax will have to compete head to head with well-established FF systems of other brands for new customers to make up for the converts. Can pentax compete on the path they have set forth without a FF?

I think that FF will become ... in the foreseeable future ..... another significant string in Ricoh's bow. So it will very much help them compete. Albeit if only the forecast numbers predicted aren't big, like the 645Z, have a minimal production run and find yourself having to re order more because of the demand ...... at least then your covering another market, will regain some of your old faithful an a handful of converts, plus a fair bit more kudos in the market.

General public will start seeing Pentax's at tennis matches with 400mm lenses on and at weddings and so it begins. Then have the entry level and new image stuff like K-S1 which will entice the up and comers.

It is logical with the k mount and as mentioned above just makes for so much practicality to be able to utilise lenses on both sets of bodies giving you what you need at any given requirement. Ultimate landscape quality or low light performance, use the FF body, then when your birding and want the reach, grab the K3 body....

I agree.  I used a Pentax K20D at weddings for a couple of years alongside Canon and Nikon gear.  Compared just fine.

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