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04-13-2016, 05:20 PM   #1
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Pentax really needs a fast prime for the 645

Somebody prove me wrong on this.

I've been thinking a lot recently and have come to the succinct conclusion that Ricoh really needs to bestow a f2.0 or faster lens upon its loyal followers preferably around the 50mm (35mm) length.

Now this may not financially be a good idea at first but lets think about this properly.

Almost all wedding film photographers pretty much use one system, the Contax. Furthermore almost all of them swear by the 80mm f2 for 95% of their work.

Its no secret that film is getting to the point that it will either be too expensive to use for wedding photographers or go out of production entirely.

Ofcourse its true that 35mm dslr's with their fast 1.4 lenses are great but looking at the capabilities of the 645z vs almost all DSLR bodies, there is no comparison, in my experience anyway.

Long story short, I'd buy one. I wish there was one to buy now and unless its unfeasible, I'd be over the moon if there was even a fart of a rumour

Am I wrong here?

04-13-2016, 07:27 PM   #2
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The 2.0 vs. 2.8 is only a 1 stop difference. Not that big of deal in terms of light especially with the amazing ISO noise control the 645Z has. So the only real benefit would be a shallower depth of field, and right now nailing perfect focus at f/2.8 is hard enough on the Z, cutting your DOF in half would really take some steady hands . Not to mention the cost difference of a lens with 1 stop difference in aperture would be much higher (and larger in size) then a 2.8 lens. The Contax is nice, but not because of the 2.0 aperture, its the overall rendering, and quality of bokeh, Instead of a f/2 Pentax id much rather see an improved 2.8 lens that has more blades and maybe even an apodization filter.
04-13-2016, 08:09 PM   #3
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QuoteOriginally posted by trusharp Quote
Somebody prove me wrong on this.

I've been thinking a lot recently and have come to the succinct conclusion that Ricoh really needs to bestow a f2.0 or faster lens upon its loyal followers preferably around the 50mm (35mm) length.
The FA43 F/1.9 is one of my all-time favorites.
04-13-2016, 08:30 PM   #4
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I was pretty happy at that FL that we have a 55/2.8

That said, I do like the idea of a "bokeh monster"-designed lens, and that is something missing from the 67 and 645 systems. Perhaps the 105/2.4 is close, but not anything like some of the K-mount offerings. just saying.

04-13-2016, 09:23 PM   #5
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This subject has been brought up before, and in any case we are unlikely to see anything faster than f/2.4* for the Pentax 645 system anytime soon.


QuoteOriginally posted by jlstrawman Quote
The FA43 F/1.9 is one of my all-time favorites
That is nice, we are talking about 645 format lenses here.


*i'm referring to the Pentax 67 105mm f/2.4 which can be used with certain caveats of the Pentax Digital 645 system.
04-13-2016, 11:09 PM   #6
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QuoteOriginally posted by mikeSF Quote
I was pretty happy at that FL that we have a 55/2.8

That said, I do like the idea of a "bokeh monster"-designed lens, and that is something missing from the 67 and 645 systems. Perhaps the 105/2.4 is close, but not anything like some of the K-mount offerings. just saying.
105/2.4 on 6x7 is equivalent of 50/1.2 on FF.

I believe it's more likely for Ricoh to start using FF 645 sensors than producing faster 645 lenses.
04-14-2016, 01:05 AM   #7
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QuoteOriginally posted by trusharp Quote
Somebody prove me wrong on this.

I've been thinking a lot recently and have come to the succinct conclusion that Ricoh really needs to bestow a f2.0 or faster lens upon its loyal followers preferably around the 50mm (35mm) length.
I do agree, but i think that Ricoh only has a fairly small amount of engineers compared to "the big guys" and I suspect 100% of their resources would be developing the 100mp successor at the moment.

I use the contax 80/2 and it's bloody hard to use. If you so much as breath it's out of focus.

04-14-2016, 02:37 AM   #8
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QuoteOriginally posted by vivavegas Quote
The 2.0 vs. 2.8 is only a 1 stop difference. Not that big of deal in terms of light especially with the amazing ISO noise control the 645Z has. So the only real benefit would be a shallower depth of field, and right now nailing perfect focus at f/2.8 is hard enough on the Z, cutting your DOF in half would really take some steady hands . Not to mention the cost difference of a lens with 1 stop difference in aperture would be much higher (and larger in size) then a 2.8 lens. The Contax is nice, but not because of the 2.0 aperture, its the overall rendering, and quality of bokeh, Instead of a f/2 Pentax id much rather see an improved 2.8 lens that has more blades and maybe even an apodization filter.
I disagree with you there, there is a distinct difference between f2.8 and 2. The way it blows out the background is very important to my work. The extra stop is just an added bonus. It's true that we need better 2.8 lenses, but if Pentax wants to carve out their name in digital MF history, they need to put out a lens faster than 2.8

---------- Post added 04-14-2016 at 10:40 AM ----------

QuoteOriginally posted by Fogel70 Quote
105/2.4 on 6x7 is equivalent of 50/1.2 on FF.

I believe it's more likely for Ricoh to start using FF 645 sensors than producing faster 645 lenses.
I think that's pretty much impossible. Correct me if I'm wrong but aren't the new lenses made for the crop medium format sensors? It doesn't make sense to develop a body with a larger sensor when the useable lens support is over a decade old.
04-14-2016, 03:09 AM - 1 Like   #9
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QuoteOriginally posted by trusharp Quote
Correct me if I'm wrong but aren't the new lenses made for the crop medium format sensors?
Some of them are, some aren't.

QuoteOriginally posted by trusharp Quote
It doesn't make sense to develop a body with a larger sensor when the useable lens support is over a decade old.
04-14-2016, 07:50 AM - 1 Like   #10
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I've been saying this since the Z came out! Mamiya had the 80/1.9, Contax has the 80/2, Hasselblad has the 110/2 and the H system as the 100/2.2, the 67 system has the 105/2.4...I'm not sure what Phase has... But the P645 system has always been left out when it comes to a fast lens! It's really a shame because the Z has the best AF of any system so a fast lens would be the most usable. Hopefully they make this happen. Something tells me though after the zooms, they'll make some leaf versions of the 55 and 90.

If you want some fast glass The Bokeh Factory can provide it, but it's going to be manual focus only. I myself am planning to get their 90/2 Summicron that they re-housed to Pentax mount.
04-14-2016, 08:16 AM   #11
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QuoteOriginally posted by Fogel70 Quote
105/2.4 on 6x7 is equivalent of 50/1.2 on FF.

I believe it's more likely for Ricoh to start using FF 645 sensors than producing faster 645 lenses.
I should have clarified, my response was to the original question which seemed to be referencing the 645Z (33x44 sensor size), not 67 nor FF 645. Sorry for that confusion. You are certainly right, there are some wonderful performers for 6x7!

---------- Post added 04-14-2016 at 08:25 AM ----------

QuoteOriginally posted by gavincato Quote
I do agree, but i think that Ricoh only has a fairly small amount of engineers compared to "the big guys" and I suspect 100% of their resources would be developing the 100mp...s.
This. Of course you are right. And the FF K-1 and its succession needs devoted resources too.
It's cool.

---------- Post added 04-14-2016 at 08:27 AM ----------

QuoteOriginally posted by Sperdynamite Quote
I've been saying this since the Z came out! Mamiya had the 80/1.9, Contax has the 80/2, Hasselblad has the 110/2 and the H system as the 100/2.2, the 67 system has the 105/2.4...I'm not sure what Phase has... But the P645 system has always been left out when it comes to a fast lens! It's really a shame because the Z has the best AF of any system so a fast lens would be the most usable. Hopefully they make this happen. Something tells me though after the zooms, they'll make some leaf versions of the 55 and 90.

If you want some fast glass The Bokeh Factory can provide it, but it's going to be manual focus only. I myself am planning to get their 90/2 Summicron that they re-housed to Pentax mount.
i have seen their site before. So do you acquire the lens you want and send to them for conversion? How does that work and it sounds very expensive, yes?

Last edited by mikeSF; 04-14-2016 at 08:25 AM.
04-14-2016, 08:34 AM   #12
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QuoteOriginally posted by Digitalis Quote
Some of them are, some aren't.


which one ? - I only know that the SMC Pentax-DA 645 25mm F4 AL [IF] SDM AW isnīt 645 Film format (44x56mm), all other Pentax 645 lenses are 645 FullFormat (FF) (and of course all the adapted lenses )
04-14-2016, 08:57 AM   #13
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QuoteOriginally posted by veraikon Quote
which one ? - I only know that the SMC Pentax-DA 645 25mm F4 AL [IF] SDM AW isnīt 645 Film format (44x56mm), all other Pentax 645 lenses are 645 FullFormat (FF) (and of course all the adapted lenses )
Also the 28-45, until 35mm AFAIK. Personally I'd rather just use the DFA 35 HD on film anyway. And...I dont' think there was every anything wider than 35mm for ANY 645 system in the film days. So I definitely don't feel like I'm missing out on anything.
04-14-2016, 09:25 AM   #14
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QuoteOriginally posted by trusharp Quote
Somebody prove me wrong on this.

I've been thinking a lot recently and have come to the succinct conclusion that Ricoh really needs to bestow a f2.0 or faster lens upon its loyal followers preferably around the 50mm (35mm) length.

Now this may not financially be a good idea at first but lets think about this properly.

Almost all wedding film photographers pretty much use one system, the Contax. Furthermore almost all of them swear by the 80mm f2 for 95% of their work.

Its no secret that film is getting to the point that it will either be too expensive to use for wedding photographers or go out of production entirely.

Ofcourse its true that 35mm dslr's with their fast 1.4 lenses are great but looking at the capabilities of the 645z vs almost all DSLR bodies, there is no comparison, in my experience anyway.

Long story short, I'd buy one. I wish there was one to buy now and unless its unfeasible, I'd be over the moon if there was even a fart of a rumour

Am I wrong here?
I totally agree. The film photographer of the wedding crowd who swear by the Contax 80 f2 will go crazy over this.
A similar 80mm f2 or 80f1.9 DFA lens will rock that industry.
I followed Contax 645 group and some have done comparison using Contax 80f2 and Pentax FA75f2.8 / 105f2.4, to me, the Contax gave a special pleasant look.

and when Pentax make that fast lens.... I will snap several 645n bodies...

Last edited by LFLee; 04-14-2016 at 09:58 AM.
04-14-2016, 09:52 AM   #15
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I totally agree with OP too. 645Z have about 2/3 of a stop sensor size advantage over FF 35mm. But the lenses lag behind by 2 full stops. That a net disadvantage of more then a stop. I think the 645 system needs both a larger sensor (FF 645), and at least one faster lens (f/1,8 or f/2,0 would be fine). If I was the designer, I would make place for a slot in apodizing element too (one that replaces an ordinary clear element).
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