HD Pentax DA * 16-50mm F2.8ED PLM AW is the second one.

reh321 · 05-22-2021, 08:54 AM

Originally posted by Serkevan

The Irix is less than half the money I expect the DFA to cost and it's quite a bit wider, it's just bulkier than I'd like.

So, you'd settle for "slower", since that would require less glass?
Or would you expect less correction/'perfection'?

**Serkevan** · 05-22-2021, 09:47 AM

Originally posted by reh321

So, you'd settle for "slower", since that would require less glass?
Or would you expect less correction/'perfection'?

The Irix is much wider (15mm is VERY wide) and that has certain glass demands.

I expect the DFA will be about as fast (OokU pointed at faster than f/2.8), and optics at least on par with the Irix (although I suppose the DFA will show more coma, though that's only truly relevant for astro).

I'd settle for "much more expensive" and a 6mm longer FL.

**RobA_Oz** · 05-22-2021, 04:59 PM - **1 Like**

Originally posted by Serkevan

The Irix is much wider (15mm is VERY wide) and that has certain glass demands.

I expect the DFA will be about as fast (OokU pointed at faster than f/2.8), and optics at least on par with the Irix (although I suppose the DFA will show more coma, though that's only truly relevant for astro).

I'd settle for "much more expensive" and a 6mm longer FL.

Perhaps my understanding is incorrect, but with a rectilinear wide-angle, I would expect simple perspective distortion to produce ellipses, rather than coma, which produces parabolas, but in any event most “astro” work with a wide-angle lens is more “landscape with stars”, rather than the stellar objects themselves being the subject, which is the preserve of long-focus lenses.

Having said that, and being the owner of an Irix 15, I should do some night-sky work with it, just to see for myself.

STARHUNTER94 · 05-24-2021, 06:09 PM - **1 Like**

Do we know yet if the 16-50 will be parfocal?

STARHUNTER94 · 06-03-2021, 06:46 PM

Anyone on that one? ^

I'm itching to know how this performs in real life too. And price.

reh321 · 06-03-2021, 09:00 PM - **1 Like**

Originally posted by STARHUNTER94

Do we know yet if the 16-50 will be parfocal?

I'm not sure people have worried much about parfocal since lenses became AF, because you can readily refocus.

house · 06-14-2021, 05:33 AM - **2 Likes**

Now is the time to set it free! Release the DA1650! Let it fly!

**lsimpkins** · 06-15-2021, 07:01 AM - **2 Likes**

Originally posted by house

Now is the time to set it free! Release the DA1650! Let it fly!

I'd love to get it in a "kit" with the K-3iii!

**demondata** · 06-15-2021, 08:04 AM - **2 Likes**

Originally posted by sundown

Good that they will use their PLM technology, should be a cracking lens.

Well, hopefully not. Heh heh.

Ishpuini · 06-15-2021, 09:38 AM

Originally posted by lsimpkins

I'd love to get it in a "kit" with the K-3iii!

If that means that silver versions will be made for the kits, and those silver lenses will be available separately, I'm all for that.

reh321 · 06-15-2021, 09:47 AM

Originally posted by Ishpuini

If that means that silver versions will be made for the kits, and those silver lenses will be available separately, I'm all for that.

I'm not sure how that would work out.
After trying the silver FA 28-105 {from my K-30} on my silver KP, I decided to get a black 20-40 Ltd for the KP.

**mlt** · 06-15-2021, 02:06 PM

Originally posted by reh321

I'm not sure how that would work out.
After trying the silver FA 28-105 {from my K-30} on my silver KP, I decided to get a black 20-40 Ltd for the KP.

Both colors of the 20-40 are good looking both on and off the camera. It is nice to have choices with the Limited lenses, not a common practice with other manufacturers.

Ishpuini · 06-15-2021, 11:50 PM

Originally posted by reh321

I'm not sure how that would work out.
After trying the silver FA 28-105 {from my K-30} on my silver KP, I decided to get a black 20-40 Ltd for the KP.

I know, sometimes black lenses do look better.

OTOH, the silver does reflect the sun and prevent the lens from heating up to the same degree as a black lens might. For travel to hot places there could be some added value in that?

reh321 · 06-16-2021, 07:25 AM

Originally posted by Ishpuini

I know, sometimes black lenses do look better.

OTOH, the silver does reflect the sun and prevent the lens from heating up to the same degree as a black lens might. For travel to hot places there could be some added value in that?

For film it might have been slightly beneficial; I'm not sure enough of a difference exists for digital.

**mlt** · 06-16-2021, 08:36 AM

At least Pentax never saw fit to do them in a glossy chrome finish.

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05-22-2021, 08:54 AM	#631
reh321 Pentaxian Join Date: Nov 2014 Location: South Bend, IN, USA Photos: Gallery \| Albums Posts: 23,175	Originally posted by Serkevan The Irix is less than half the money I expect the DFA to cost and it's quite a bit wider, it's just bulkier than I'd like. So, you'd settle for "slower", since that would require less glass? Or would you expect less correction/'perfection'?

05-22-2021, 09:47 AM	#632
Serkevan Site Supporter Join Date: May 2019 Photos: Albums Posts: 5,976	Originally posted by reh321 So, you'd settle for "slower", since that would require less glass? Or would you expect less correction/'perfection'? The Irix is much wider (15mm is VERY wide) and that has certain glass demands. I expect the DFA will be about as fast (OokU pointed at faster than f/2.8), and optics at least on par with the Irix (although I suppose the DFA will show more coma, though that's only truly relevant for astro). I'd settle for "much more expensive" and a 6mm longer FL.

05-22-2021, 04:59 PM - 1 Like	#633
RobA_Oz Site Supporter Join Date: Nov 2008 Location: Tasmania, Australia Photos: Gallery Posts: 8,191	Originally posted by Serkevan The Irix is much wider (15mm is VERY wide) and that has certain glass demands. I expect the DFA will be about as fast (OokU pointed at faster than f/2.8), and optics at least on par with the Irix (although I suppose the DFA will show more coma, though that's only truly relevant for astro). I'd settle for "much more expensive" and a 6mm longer FL. Perhaps my understanding is incorrect, but with a rectilinear wide-angle, I would expect simple perspective distortion to produce ellipses, rather than coma, which produces parabolas, but in any event most “astro” work with a wide-angle lens is more “landscape with stars”, rather than the stellar objects themselves being the subject, which is the preserve of long-focus lenses. Having said that, and being the owner of an Irix 15, I should do some night-sky work with it, just to see for myself.

05-24-2021, 06:09 PM - 1 Like	#634
STARHUNTER94 Pentaxian Join Date: Jul 2019 Posts: 771	Do we know yet if the 16-50 will be parfocal?

06-03-2021, 06:46 PM	#635
STARHUNTER94 Pentaxian Join Date: Jul 2019 Posts: 771	Anyone on that one? ^ I'm itching to know how this performs in real life too. And price.

06-03-2021, 09:00 PM - 1 Like	#636
reh321 Pentaxian Join Date: Nov 2014 Location: South Bend, IN, USA Photos: Gallery \| Albums Posts: 23,175	Originally posted by STARHUNTER94 Do we know yet if the 16-50 will be parfocal? I'm not sure people have worried much about parfocal since lenses became AF, because you can readily refocus.

06-14-2021, 05:33 AM - 2 Likes	#637
house Pentaxian Join Date: May 2015 Photos: Albums Posts: 3,306	Now is the time to set it free! Release the DA1650! Let it fly!

06-15-2021, 07:01 AM - 2 Likes	#638
lsimpkins Site Supporter Join Date: Feb 2013 Location: SE Pennsylvania Photos: Gallery \| Albums Posts: 537	Originally posted by house Now is the time to set it free! Release the DA1650! Let it fly! I'd love to get it in a "kit" with the K-3iii!

06-15-2021, 08:04 AM - 2 Likes	#639
demondata Site Supporter Join Date: Oct 2006 Location: Aurora, Ontario, Canada Photos: Gallery Posts: 632	Originally posted by sundown Good that they will use their PLM technology, should be a cracking lens. Well, hopefully not. Heh heh.

06-15-2021, 09:38 AM	#640
Ishpuini Veteran Member Join Date: Sep 2006 Location: Antwerp, Belgium Photos: Gallery Posts: 1,727	Originally posted by lsimpkins I'd love to get it in a "kit" with the K-3iii! If that means that silver versions will be made for the kits, and those silver lenses will be available separately, I'm all for that.

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06-15-2021, 09:47 AM	#641
reh321 Pentaxian Join Date: Nov 2014 Location: South Bend, IN, USA Photos: Gallery \| Albums Posts: 23,175	Originally posted by Ishpuini If that means that silver versions will be made for the kits, and those silver lenses will be available separately, I'm all for that. I'm not sure how that would work out. After trying the silver FA 28-105 {from my K-30} on my silver KP, I decided to get a black 20-40 Ltd for the KP.

06-15-2021, 02:06 PM	#642
mlt Site Supporter Join Date: Dec 2007 Posts: 1,159	Originally posted by reh321 I'm not sure how that would work out. After trying the silver FA 28-105 {from my K-30} on my silver KP, I decided to get a black 20-40 Ltd for the KP. Both colors of the 20-40 are good looking both on and off the camera. It is nice to have choices with the Limited lenses, not a common practice with other manufacturers.

06-15-2021, 11:50 PM	#643
Ishpuini Veteran Member Join Date: Sep 2006 Location: Antwerp, Belgium Photos: Gallery Posts: 1,727	Originally posted by reh321 I'm not sure how that would work out. After trying the silver FA 28-105 {from my K-30} on my silver KP, I decided to get a black 20-40 Ltd for the KP. I know, sometimes black lenses do look better. OTOH, the silver does reflect the sun and prevent the lens from heating up to the same degree as a black lens might. For travel to hot places there could be some added value in that?

06-16-2021, 07:25 AM	#644
reh321 Pentaxian Join Date: Nov 2014 Location: South Bend, IN, USA Photos: Gallery \| Albums Posts: 23,175	Originally posted by Ishpuini I know, sometimes black lenses do look better. OTOH, the silver does reflect the sun and prevent the lens from heating up to the same degree as a black lens might. For travel to hot places there could be some added value in that? For film it might have been slightly beneficial; I'm not sure enough of a difference exists for digital.

06-16-2021, 08:36 AM	#645
mlt Site Supporter Join Date: Dec 2007 Posts: 1,159	At least Pentax never saw fit to do them in a glossy chrome finish.