[JPT]

Since the HD Pentax Limited lenses are now in the shops in Japan, I was able to bring my own SMC DA21 and take a comparison shot with the two lenses. It didn't go quite according to plan, because I got nervous under the beady eyes of about four shop assistants and rushed the job. I ended up with shots that were not framed exactly the same and focused on different points. I thought I'd share my observations about the lens and the samples anyway.

On the top is the green-striped SMC lens and underneath is the red-striped HD lens. Both at f3.2, 1/100, ISO200, AWB, JPEG Natural. Since I'm posting these crops one above the other, please be aware of any colour shift in your monitor.





The whole frame side by side - SMC on left, HD on right. I was trying to focus on the P of the black and white Pentax sign, but the SMC shot is focused considerable further back.



Observations
- There is no strange magenta colour cast coming from the HD coating as far as I can see.
- HD produced an overall darker image at the same settings.
- SMC shows noticeably more yellow chromatic aberration in the fluorescent lighting, especially to the left of the column with the Pentax sign. HD still has some CA, but you have to look closer.
- I can't see any difference in build quality. The focus ring feels the same.
- I used a K-01 with the latest firmware and the old and new lenses focused the same - same speed, same noise.

I don't think the difference is huge, but it's certainly there.

[aurele]

i don't want to be the annoying guy, but you should have used some preset White balance instead of Auto, so the difference in color cast for exemple would have been more visible, i guess.

Otherwise i wonder why the HD did produce a darker frame.

Thanks for the other info about lens construction

[JimmyDranox]

The diference in coatings can make diference in exposure time. But the exposure times are in steps, so, a little more light to the sensor can make the camera to set a little too short exposure, so, in this way, HD lens can produce darker frames.

[yusuf]

As I was reading somewhere, no more starbursts on DA 15 with the new HD coating. Have you noticed something similar?

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Last edited by yusuf; 10-06-2013 at 09:20 AM.

[LowVoltage]

As I was reading somewhere, no more starbursts on DA 15 with the new HD coating. Have you noticed something similar?

An interesting question, as the new HD versions all have rounded aperture blades. I rarely go for this effect, so I haven't bothered to experiment with lenses that have the rounded blades. Can anyone comment on this phenomenon?

[JinDesu]

No, the new HD 15 does not have rounded blades.

[Adam]

An interesting question, as the new HD versions all have rounded aperture blades. I rarely go for this effect, so I haven't bothered to experiment with lenses that have the rounded blades. Can anyone comment on this phenomenon?

I don't think any conclusions can be drawn from this as one SMC versions seems to not have focused properly. The best way to test out the new coating, if you have a chance, would be to shoot a photo with direct sunlight or a night photo with a bunch of light sources (or even a full moon).

Adam
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[kh1234567890]

An interesting question, as the new HD versions all have rounded aperture blades. I rarely go for this effect, so I haven't bothered to experiment with lenses that have the rounded blades. Can anyone comment on this phenomenon?

To get starbursts you usually need to stop the lens right down. OTOH curved aperture blades are used to make the aperture more circular when nearly wide open. In practice it will probably make little difference to starbursts or bokeh - the real reason is marketing, since some Canikon lenses have them.

Nice quick comparison - so is HD worth the extra money ?

[mano]

Thanks for the comparison!

And I'm still undecided...

[bdery]

To get starbursts you usually need to stop the lens right down.

Not really, no. I usually shoot my DA21 quite wide, and get nice starburst effects. For instance, f5,6

curved aperture blades are used to make the aperture more circular when nearly wide open. In practice it will probably make little difference to starbursts or bokeh

Rounded apertures are NOT a gimmick. They will decrease the starbust effect but improve thye texture of the bokeh. Here's what you get when you don't have them:

[LowVoltage]

No, the new HD 15 does not have rounded blades.

Really? Then somebody should change the PF Pentax Lens database entry!

[SyncGuy]

I really think they shouldn't have changed the DA15 to rounded blades.... Sure, add more blades for more star trails but not the rounded blades...

Maybe every lens except DA15 and DA21..

Heck! Slap in an odd-numbered NON-rounded aperture blades into the DA14/2.8 to give it some life!

Rounded blades are mostly for smoother bokeh... Seriously, a wide angle used for bokeh? LoL!
I know it's doable but isn't the common usage for wide angles or super wides more for scenery? And they had to kill the starburst considerably..

[vjacesslav]

Here is the thing...
New HD DA 15mm Ltd has smart design of aperture blades... From round to classic one... When the lens is fully open, the blades are round at the end, so the effect is takin pictures with smooth bokeh...
When You stop down, specially for night shoots with stars F8 and more, the blades are not round all, so the hole od aperture si not rounded and it is more like on classic SMC HD 15mm, so the "stars" are back...

[Andi Lo]

Here is the thing...
New HD DA 15mm Ltd has smart design of aperture blades... From round to classic one... When the lens is fully open, the blades are round at the end, so the effect is takin pictures with smooth bokeh...
When You stop down, specially for night shoots with stars F8 and more, the blades are not round all, so the hole od aperture si not rounded and it is more like on classic SMC HD 15mm, so the "stars" are back...

So smart... Bravo Ricoh

[topace]

Here is the thing...
New HD DA 15mm Ltd has smart design of aperture blades... From round to classic one... When the lens is fully open, the blades are round at the end, so the effect is takin pictures with smooth bokeh...
When You stop down, specially for night shoots with stars F8 and more, the blades are not round all, so the hole od aperture si not rounded and it is more like on classic SMC HD 15mm, so the "stars" are back...

On most lenses I've seen, when the aperture is fully open, it receeds behind a circular ring, making very round bokeh circles. Is that not the case with the 15mm Ltd?