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02-03-2019, 02:23 PM - 1 Like   #1
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HD FA35 f/2 vs FA35 f/2 - hybrid aspherical vs ground glass aspherical element?

Having recently pre-ordered the new HD FA35mm f/2, I've just noticed the specifications state that it includes "hybrid aspherical optical elements", whereas the original FA35 f/2 - if I remember correctly - used a (more expensive to produce) ground glass aspherical element. It seems this little detail might have slipped below the radar so far?

I can't say I'm particularly concerned... my "plastic fantastic" DA35 f/2.4 includes a hybrid element, as do several of my other lenses, and I'm perfectly happy with the performance - but it's a surprising (if small) downgrade(?) that might temper the excitement of the upgrades for some folks. As I understand it, hybrid elements may be more susceptible to environmental changes such as humidity and temperature... though "more susceptible" might still mean "irrelevant" in this case (frankly, I'm not qualified to judge). Some world-class lenses include hybrid elements, so I doubt it's a cause for concern...

It's interesting that the glass isn't exactly the same as the FA35/2, though. This suggests that Ricoh might not simply be using up stocks of existing FA35/2 components in the new lens... That in fact, HD FA35/2 is being manufactured from entirely new component stock.

Anyway, this doesn't affect my interest or order at all. I just thought it was an interesting difference


Last edited by BigMackCam; 02-03-2019 at 04:27 PM.
02-03-2019, 04:01 PM   #2
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Enjoy comparison..

????????HD PENTAX-FA 35mm F2 ????? !!! HD ??????-FA 35mm F2 ??? - ??????????by????????

Basically still the same lens with slightly improved reflection control. But the main pain - hexagonal bokeh - is still there..
02-03-2019, 04:04 PM   #3
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QuoteOriginally posted by xmeda Quote
Enjoy comparison..

????????HD PENTAX-FA 35mm F2 ????? !!! HD ??????-FA 35mm F2 ??? - ??????????by????????

Basically still the same lens with slightly improved reflection control. But the main pain - hexagonal bokeh - is still there..
Thanks...

I already knew it was basically the same lens, except for HD and SP coatings, new focus ring and different external finish. I've posted about this already in a few other threads. I could care less about the six blade aperture, given the quality of out-of-focus rendering of the old model and the DA35 f/2.4 which is based on the same optical formula...

But what I'm pointing out here... the purpose of my thread... is the different aspherical element construction. The specification for the new HD version says it's a hybrid element - which isn't the same as the older lens' ground glass element.

Do you have any further information or views on that?
02-03-2019, 04:25 PM - 2 Likes   #4
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@Digitalis would be one of the best to comment here. I believe the hybrid is cheaper to manufacture and is better at controlling aberrations. I don’t really see a down side to it.

02-03-2019, 05:12 PM - 1 Like   #5
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QuoteOriginally posted by BigMackCam Quote
Having recently pre-ordered the new HD FA35mm f/2, I've just noticed the specifications state that it includes "hybrid aspherical optical elements", whereas the original FA35 f/2 - if I remember correctly - used a (more expensive to produce) ground glass aspherical element. It seems this little detail might have slipped below the radar so far?
That's disappointing if true, Mike.

It makes it even more similar then to the DA35 f2.4 … it uses hybrid instead of glass to reduce cost.

If you'll forgive the source material:

RiceHigh's Pentax Blog: DA(L)35/2.4 Just a Re-packaged FA35/2!?

Needless to say, the aspherical element in the FA31 Limited is all-glass.

BTW, a comparison with lots of photos here:

https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/118765-da-...ny-photos.html
02-03-2019, 05:16 PM - 1 Like   #6
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QuoteOriginally posted by twilhelm Quote
@Digitalis would be one of the best to comment here. I believe the hybrid is cheaper to manufacture and is better at controlling aberrations. I don’t really see a down side to it.
No, a single glass element is better, and ground rather than molded.
02-03-2019, 05:22 PM   #7
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Don't let the Sony troll fan club know about this element change.

02-03-2019, 05:33 PM - 1 Like   #8
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QuoteOriginally posted by clackers Quote
That's disappointing if true, Mike.

It makes it even more similar then to the DA35 f2.4 … it uses hybrid instead of glass to reduce cost.
It's not mentioned on Ricoh's own websites, but my SRS (my supplier) states it, and it appears in the ephotozine announcement towards the end:
HD Pentax-FA 35mm f/2 AL Lens Announced
02-03-2019, 06:02 PM - 1 Like   #9
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SRS are a great camera shop, they always sent me good copies of lenses. I requested a good copy of the Samyang 14mm which is notorious for bad copies and they did. The advantage of a good camera shop versus multi product selling monster corporations!
02-03-2019, 06:24 PM   #10
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Hmm. This change seems odd, since they've been making the original right along and would not have to change tooling. All they'd need to do is up the coatings and charge extra for that, and change the printed ID on the lens body. I am a little surprised and disappointed that since the body is a redesign it would not include a DC motor and WR.
02-03-2019, 06:54 PM   #11
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Is it possible the FA35 has a hybrid element as well, and they just didn’t say anything about it?

I remember a number of ‘plastic lenses’ that didn’t advertise it in the 90s...

-Eric
02-03-2019, 07:32 PM   #12
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For the original lens. smc FA 35mm f/2, hybrid aspherical element is mentioned in the first description paragraph here:

smc PENTAX-FA 35mmF2AL / Wide-Angle Lenses / K-mount Lenses / Lenses / Products | RICOH IMAGING

"This lens provides sharp images with high contrast over the entire image and at all focal lengths.
[FA 35mm F2 AL] The lens has an optical system using a hybrid aspherical lens and ghostless coating..."



Aspherical lenses are described at the Lens Technology page (click on About lens technology on the FA 35 page):

"AL=Aspherical Lens Various types of aberration can occur in optical lenses that hinder the achieving of the ideal imaging performance. One type is spherical aberration where the light rays do not converge in a single focal point, resulting in blurring of the point image. Aspherical lenses (AL) can be used to minimize this aberration and reduce the number of component lenses for enabling a compact, high-performance lens design. In addition to glass-molded aspherical lenses, PENTAX has developed hybrid aspherical lenses, where special transparent resin is affixed to optical glass, and resin molded aspherical lenses. The optimal aspherical lens is selected based on the lens configuration, aperture size, application, and other factors."


I wonder what is the significance of the plural "hybrid aspherical optical elements" indicated in the description for the new lens.

Last edited by c.a.m; 02-04-2019 at 06:25 AM.
02-03-2019, 08:44 PM   #13
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QuoteOriginally posted by BigMackCam Quote
It's not mentioned on Ricoh's own websites, but my SRS (my supplier) states it, and it appears in the ephotozine announcement towards the end:
HD Pentax-FA 35mm f/2 AL Lens Announced
QuoteOriginally posted by c.a.m Quote
smc FA 35mm f/2 lens: Hybrid aspherical element is mentioned in the first description paragraph here:

smc PENTAX-FA 35mmF2AL / Wide-Angle Lenses / K-mount Lenses / Lenses / Products | RICOH IMAGING

"This lens provides sharp images with high contrast over the entire image and at all focal lengths.
[FA 35mm F2 AL] The lens has an optical system using a hybrid aspherical lens and ghostless coating..."



Aspherical lenses are highlighted at the Lens Technology page (click on About lens technology on the FA 35 page):

AL=Aspherical Lens Various types of aberration can occur in optical lenses that hinder the achieving of the ideal imaging performance. One type is spherical aberration where the light rays do not converge in a single focal point, resulting in blurring of the point image. Aspherical lenses (AL) can be used to minimize this aberration and reduce the number of component lenses for enabling a compact, high-performance lens design. In addition to glass-molded aspherical lenses, PENTAX has developed hybrid aspherical lenses, where special transparent resin is affixed to optical glass, and resin molded aspherical lenses. The optimal aspherical lens is selected based on the lens configuration, aperture size, application, and other factors.


I wonder what is the significance of the plural "hybrid aspherical optical elements" indicated in the description for the new lens.
K-mount page describes the FA35/2AL as having “aspherical element(s)” I think there might not be enough difference to make a difference between the two designs. Perhaps the alleged) addition of a hybrid aspherical element justifies naming this a new lens rather than a design update?

AFAIC adding the beaded focusing ring won’t do much for manual focusing unless the resistance of the helicoid has been increased. On the FA there is almost no feel when manually focusing; reputedly the helicoid was made loose to ensure the focusing motor could move the helicoid quickly. Given that current cameras have a more powerful in-body focusing motor perhaps the helicoid has a bit more resistance for manual focusing feel.

It is getting harder to resist the temptation to re-buy this lens. B&H has the old version In Stock for $289.

Last edited by monochrome; 02-03-2019 at 08:55 PM.
02-03-2019, 09:36 PM - 1 Like   #14
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Looking at the lens cross-section, the “hybrid” aspherical element appears as if the glass component may be convex spherical on the rear surface, and the small concave surface at the front may be the synthetic material, attached to it. But I’m guessing.

In any event, the construction appears to be the same for both versions, so the “hybrid” element possibly isn’t new.
02-03-2019, 09:40 PM   #15
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QuoteOriginally posted by RobA_Oz Quote
Looking at the lens cross-section, the “hybrid” aspherical element appears as if the glass component may be convex spherical on the rear surface, and the small concave surface at the front may be the synthetic material, attached to it. But I’m guessing.

In any event, the construction appears to be the same for both versions, so the “hybrid” element possibly isn’t new.
I suspect you are correct.
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