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12-12-2011, 05:46 AM   #16
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QuoteOriginally posted by DogLover Quote
The jump is actually from 21-31, plus the two 35s.
Ah yes, forgot that some FA primes are still in production.
Pentax-FA 31mm F1.8 AL Limited

12-12-2011, 06:02 AM   #17
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QuoteOriginally posted by Docrwm Quote
Why 26 and not 28?
28? Boooooooring!
12-12-2011, 06:54 AM   #18
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QuoteOriginally posted by causey Quote
QuoteOriginally posted by Docrwm:
Why 26 and not 28?
28? Boooooooring!
Yeah, 28 has been done a few times. [yawn]

But 26 makes sense for APS-C. The FF FOV equivalent would be 39mm, close enough to 40mm, and 40mm FF lenses were made. I have a couple: a tiny pancake Meyer Helioplan 40/4.5 and a big Kilfitt Makro Kilar E 40/3.5 (1:2) which I read was the first SLR macro lens. (I say the Kilfitt is big, but much of its body is a deep inset functioning as a built-in lens hood; without that, it would be almost a pancake.)

Consider: a DA26 matched with the FA31 would give Pentax a little cluster of lenses *around* the APS-C 'normal' focal length. Better yet, a DFA26 would be a nice tool on the upcoming FF cam. It would hopefully be smaller than the M42 Lentar-Tokina 25/3.5's I've had. Now if they could just keep the weight around 100g... it would be perfect for my micro-kit of tiny lightweight lenses. Except for cost, of course.
12-12-2011, 07:11 AM   #19
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Yes, the 28 has been made before. But when did that become a reason for not making a sensible lens? Should Pentax stop making fifties?

28mm is as close to a perfect "normal" as one can get, and I want one!

12-12-2011, 07:20 AM   #20
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QuoteOriginally posted by savoche Quote
Yes, the 28 has been made before. But when did that become a reason for not making a sensible lens? Should Pentax stop making fifties?

28mm is as close to a perfect "normal" as one can get, and I want one!
When 28 was popular it was the low cost wide angle that most togs would own. Arguably the 31/35 ar now the normal lens
Where though is the 24?? or 23, that would be a 35 the other very popular WA in film days. On film my preference was really wide (ie my 21 or a 24, and then up to a 35 and skipped over 28 which was always too wide or not wide enough for me)
I do like using my M28 as a normal on digital though. There is a Sigma 28 (and a 24 for that matter) both are fast as well, something Pentax doesn't seem to focus on any more in WA anyway (the DA* 55 is nice though )
12-12-2011, 07:41 AM   #21
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A DA28 Ltd or a DA29 Ltd ( Nice odd length of Pentax) would be a good crop equivalent of the great FA43 Ltd, which was consider a perfecg focal length for film. Make it a DFA28 Ltd or a DFA29 Ltd just incase Pentax gets a FF to market.

Dave
12-12-2011, 05:49 PM   #22
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As I see it, something around 24-26mm makes sense in that Pentax is obviously pushing the 35 as the "normal", and a 28 is just too close to 35 to convince many to buy both. I think Pentax would get more people to buy into a 15 - 24/26 - 35/40 lineup than, say, a 21-28-35.

Of course, there are plenty of existing 28mm designs to leverage, and pretty much no 26's. So for that reason alone we might eventually see a 28.
12-12-2011, 06:01 PM   #23
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QuoteOriginally posted by eddie1960 Quote
When 28 was popular it was the low cost wide angle that most togs would own.
Yep except for the K28/2.0. It was equivalent in price to the K18/3.5 and cost double the K28/3.5. The K28/2.0 had a list price of $471.00 in Jan/78.

Phil.

12-12-2011, 06:07 PM   #24
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The missing focal length for Pentax is 24mm, not 28mm.
12-12-2011, 06:14 PM   #25
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QuoteOriginally posted by Marc Sabatella Quote
As I see it, something around 24-26mm makes sense in that Pentax is obviously pushing the 35 as the "normal", and a 28 is just too close to 35 to convince many to buy both. I think Pentax would get more people to buy into a 15 - 24/26 - 35/40 lineup than, say, a 21-28-35.

Of course, there are plenty of existing 28mm designs to leverage, and pretty much no 26's. So for that reason alone we might eventually see a 28.
I'm beginning to see the sense from the math standpoint regarding the distribution of lenses, however the last point is one that I have been thinking about for some time - there are a lot of good designs already for 28s out there so development of a 28 would be pennies compared to a completely novel length like a 26.
12-12-2011, 06:17 PM   #26
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QuoteOriginally posted by creampuff Quote
The missing focal length for Pentax is 24mm, not 28mm.
It's still amazing to me. There's a 21 and a 35 so a 28 would be 7 from each - right in the middle. I know there is a 31Ltd from the FA series but its ..well....kinda pricey. Perhaps a nice 24-28 length lens akin to the DA35/2.4?
12-12-2011, 07:10 PM   #27
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24mm on APS-C is equivalent to the old "standard" wide-angle of 35mm (60 degree diagonal) on 135 film.
Unfortunately, it doesn't seem to be an easy focal length to design, especially with autofocus.
The Pentax FA*24/2 and Nikkor AF 24/2.8 don't cover the edges very well,
the Canon EF24/2.8 has focus shift,
and the other options are very large.
Maybe something like the new Zeiss ZA 24/2 would be the best kind of compromise,
but that would have to be expensive.
12-12-2011, 08:19 PM   #28
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QuoteOriginally posted by lytrytyr Quote
24mm on APS-C is equivalent to the old "standard" wide-angle of 35mm (60 degree diagonal) on 135 film.
Unfortunately, it doesn't seem to be an easy focal length to design, especially with autofocus.
The Pentax FA*24/2 and Nikkor AF 24/2.8 don't cover the edges very well,
the Canon EF24/2.8 has focus shift,
and the other options are very large.
Maybe something like the new Zeiss ZA 24/2 would be the best kind of compromise,
but that would have to be expensive.
Good points, while we know that a very nice 28 that is small can be designed and not cost a fortune......
12-12-2011, 09:01 PM   #29
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QuoteOriginally posted by Docrwm Quote
There's a 21 and a 35 so a 28 would be 7 from each - right in the middle.
A couple mm matter more at shorter than longer FLs. Often the next jump beyond 35mm is to 45mm (I have a pancake Chinon 45/2.8 in PK-M). The logical place for a lens between 21-35mm is at 26mm. I don't know if that's an easy-design FL. I know Tokina had an M42 25/3.5 that wasn't large nor bad optically (although both my copies had stuck apertures). And of course Meyer-Pentacon had a 29mm.

I'm also curious as to how accurate are these specified focal lengths and apertures. I've read that the FA50/1.4 is actually more like 52/1.5. Can we really distinguish FOV differences between 19-20-21, 24-25, 28-29-30-31, 35-37, 43-45, 50-52 (I've had Industars and Ektars marked 52mm), 55-58, 80-85-90, 100-105-110, etc? Wouldn't it be funny if the FA31Ltd is actually a 29? What's the tolerance in specs?

NOTE: Various lensmakers churned out both consumer and professional copy lenses marked as 49-50-51-52-53-56mm -- I've had lenses with all those focal lengths. I've also seen the same lens in different brands marked as f/3.8, f/3.9, f/4. I suspect that's a marketing ploy, eh? And if we're marketing... how about if Pentax is known as the brand with the weird focal lengths? 14-21-26-31 certainly make a jarring pattern.

Last edited by RioRico; 12-12-2011 at 09:09 PM.
12-13-2011, 11:52 PM   #30
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18-55 can help you

kidding, go for A28 and MF
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