What lens is this?

**Baard-Einar** · 08-14-2021, 03:03 AM

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Hello

I became across this "fully functional" "SMC Pentax-A 20mm F2.8" but this is not a Pentax lens. Any ideas what it actually is?

Just love the rating:
EXC+++++
Optical near mint (even with a "crack" in the front element)
Body EXC++++

?Exc+++++ ? SMC Pentax A 20mm f/2.8 Wide Angle MF Lens Japan # 766 | eBay

**i_trax** · 08-14-2021, 03:18 AM

The hood is from Pentax SMC A but the rest is not.
Highly overpriced , forget about it.

**pepperberry farm** · 08-14-2021, 03:59 AM

I'm wondering if they didn't just re-house the optics... I'd be very wary of spending any money on that....

HarisF1 · 08-14-2021, 04:10 AM

Looks like a mount swap to me. The optics look like the A 20/2.8.

And where's the crack on the front element? Looks fine.

**Baard-Einar** · 08-14-2021, 04:24 AM

Originally posted by HarisF1

Looks like a mount swap to me. The optics look like the A 20/2.8.

And where's the crack on the front element? Looks fine.

The aperture ring is made in chrome and marked 3.5 and not 2.8 and the focus ring looks to be modified and very narrow.

HarisF1 · 08-14-2021, 04:38 AM

Originally posted by Baard-Einar

The aperture ring is made in chrome and marked 3.5 and not 2.8 and the focus ring looks to be modified and very narrow.

Yes, mount swap with changed rings. The front and rear optics are from the A20.

**boriscleto** · 08-14-2021, 04:45 AM

Quote:

Total ConditionEXC+++++Optical : Near MintBody: Exc++++

**UncleVanya** · 08-14-2021, 05:30 AM

The rear looks like a camera mount that was pulled off!

---------- Post added 08-14-21 at 08:31 AM ----------

Originally posted by HarisF1

And where's the crack on the front element? Looks fine.

Image 1/8 - crack isn’t in the glass, it’s near the edge on the surrounding face.

**DonV** · 08-14-2021, 05:58 AM

A "Franken" -lens.

35mmfilmfan · 08-14-2021, 06:12 AM - **1 Like**

It's pronounced "Fronkensteen"

Not a Number · 08-14-2021, 09:26 AM

Some kind of Frankenlens for sure. Looks like it has a collapsible rubber hood under the Pentax hood as well.

Wasp · 08-14-2021, 09:40 AM

The front part is SMC Pentax A 20mm f/2.8 but this is not a K mount. It takes a cap so it must be some standard thing, but I have no idea what it is. Some movie camera perhaps?

Oldbayrunner · 08-14-2021, 12:26 PM

Looks to me like an adaptall lens missing the silver locking rim for the mount adapter to latch to.

pschlute · 08-14-2021, 12:42 PM

Looks like the offspring of Frankenstein to me.

**UncleVanya** · 08-14-2021, 05:53 PM

Look at the rear ring. It looks very much like a camera Mount ring. There are screw holes some of which look worn.

It could also simply be missing that part of the lens.

08-14-2021, 03:03 AM	#1
Baard-Einar Site Supporter Join Date: Jan 2010 Location: Oslo Photos: Gallery Posts: 964	What lens is this? Staff note: This post may contain affiliate links, which means Pentax Forums may earn a small commission if a visitor clicks through and makes a purchase. If you would like to support the forum directly, you may also make a donation here. Hello I became across this "fully functional" "SMC Pentax-A 20mm F2.8" but this is not a Pentax lens. Any ideas what it actually is? Just love the rating: EXC+++++ Optical near mint (even with a "crack" in the front element) Body EXC++++ ?Exc+++++ ? SMC Pentax A 20mm f/2.8 Wide Angle MF Lens Japan # 766 \| eBay

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08-14-2021, 03:18 AM	#2
i_trax Loyal Site Supporter Join Date: Jan 2011 Location: Perth Western Australia Photos: Gallery \| Albums Posts: 2,621	The hood is from Pentax SMC A but the rest is not. Highly overpriced , forget about it.

08-14-2021, 03:59 AM	#3
pepperberry farm amateur dirt farmer Join Date: Dec 2014 Location: probably out in a field somewhere... Photos: Gallery \| Albums Posts: 41,676	I'm wondering if they didn't just re-house the optics... I'd be very wary of spending any money on that....

08-14-2021, 04:10 AM	#4
HarisF1 Veteran Member Join Date: Apr 2016 Posts: 543	Looks like a mount swap to me. The optics look like the A 20/2.8. And where's the crack on the front element? Looks fine.

08-14-2021, 04:24 AM	#5
Baard-Einar Site Supporter Join Date: Jan 2010 Location: Oslo Photos: Gallery Posts: 964 Original Poster	Originally posted by HarisF1 Looks like a mount swap to me. The optics look like the A 20/2.8. And where's the crack on the front element? Looks fine. The aperture ring is made in chrome and marked 3.5 and not 2.8 and the focus ring looks to be modified and very narrow.

08-14-2021, 04:38 AM	#6
HarisF1 Veteran Member Join Date: Apr 2016 Posts: 543	Originally posted by Baard-Einar The aperture ring is made in chrome and marked 3.5 and not 2.8 and the focus ring looks to be modified and very narrow. Yes, mount swap with changed rings. The front and rear optics are from the A20.

08-14-2021, 04:45 AM	#7
boriscleto Loyal Site Supporter Join Date: Dec 2009 Location: North Syracuse, NY Photos: Gallery Posts: 16,475	Quote: Total ConditionEXC+++++Optical : Near MintBody: Exc++++

08-14-2021, 05:30 AM	#8
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,401	The rear looks like a camera mount that was pulled off! ---------- Post added 08-14-21 at 08:31 AM ---------- Originally posted by HarisF1 And where's the crack on the front element? Looks fine. Image 1/8 - crack isn’t in the glass, it’s near the edge on the surrounding face.

08-14-2021, 05:58 AM	#9
DonV Site Supporter Join Date: Jan 2017 Location: Near Charlotte NC Photos: Albums Posts: 693	A "Franken" -lens.

08-14-2021, 06:12 AM - 1 Like	#10
35mmfilmfan Pentaxian Join Date: Oct 2016 Location: Norfolk, UK Posts: 4,329	It's pronounced "Fronkensteen"

08-14-2021, 09:26 AM	#11
Not a Number Moderator Join Date: Mar 2012 Location: Venice, CA Posts: 10,526	Some kind of Frankenlens for sure. Looks like it has a collapsible rubber hood under the Pentax hood as well.

08-14-2021, 09:40 AM	#12
Wasp Pentaxian Join Date: Mar 2017 Location: Pretoria Photos: Gallery Posts: 4,661	The front part is SMC Pentax A 20mm f/2.8 but this is not a K mount. It takes a cap so it must be some standard thing, but I have no idea what it is. Some movie camera perhaps?

08-14-2021, 12:26 PM	#13
Oldbayrunner Pentaxian Join Date: Mar 2013 Posts: 1,665	Looks to me like an adaptall lens missing the silver locking rim for the mount adapter to latch to.

08-14-2021, 12:42 PM	#14
pschlute Moderator Loyal Site Supporter Join Date: Mar 2007 Location: Surrey, UK Photos: Gallery Posts: 8,198	Looks like the offspring of Frankenstein to me.

08-14-2021, 05:53 PM	#15
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,401	Look at the rear ring. It looks very much like a camera Mount ring. There are screw holes some of which look worn. It could also simply be missing that part of the lens.