Lens coatings on Super-Takumar 55mm F2 (ver. 2 early) ??

Kurt_S · 12-17-2020, 09:55 AM

I have my dad's broken Pentax SV and a couple of M42 lenses. One lens is badly battered, but may be worth some effort to restore (sentimentally). It is the Super-Takumar 55mm F2 (ver. 2 early), as described in the forum lens reviews. A couple bits of info are not listed on the lens page, hoping that someone can answer from their knowledge or experience.

1. Were there any optical coatings on this lens?
2. Are there any thoriated elements in this lens?

SMC/Super-/Auto-Takumar 55mm F2 Reviews - M42 Screwmount Normal Primes - Pentax Lens Reviews & Lens Database

Many thanks!
Kurt

**GUB** · 12-17-2020, 10:03 AM - **1 Like**

Yes to both

stevebrot · 12-17-2020, 10:17 AM - **1 Like**

Originally posted by Kurt_S

I have my dad's broken Pentax SV and a couple of M42 lenses. One lens is badly battered, but may be worth some effort to restore (sentimentally). It is the Super-Takumar 55mm F2 (ver. 2 early), as described in the forum lens reviews. A couple bits of info are not listed on the lens page, hoping that someone can answer from their knowledge or experience.

1. Were there any optical coatings on this lens?
2. Are there any thoriated elements in this lens?

SMC/Super-/Auto-Takumar 55mm F2 Reviews - M42 Screwmount Normal Primes - Pentax Lens Reviews & Lens Database

Many thanks!
Kurt

Definite yes to #1 and possibly no to #2. The earliest versions of the ST 55/1.8 and ST 55/2.0 don't have thoriated glass, the later versions all do. There is a serial number range that I don't recall at this moment. The rule of thumb is that yellowing of the glass itself (not the reflection from the coating) is strong indication of a lens with one or more thoriated elements. Look through the lens at a sheet of white paper in natural light and compare the appearance to what you see with your eyes alone. If it looks yellowish/brownish through the lens, it is likely thoriated.

Steve

(...owns both thoriated and non-thoriated versions of the ST 55/1.8...)

stevebrot · 12-17-2020, 11:34 AM - **1 Like**

BTW...

Welcome to the Pentax Forums!

Steve

Kurt_S · 12-17-2020, 02:50 PM

Thank you, Steve and GUB. I asked because my dad made his living by building custom cars. He got his hands dirty all the time - oftentimes with solvents. It looks like he accidentally left a thumbprint on the front element! I'll keep the camera/lens for the memories (he engraved his name on the camera). I was just trying to decide if it was worth repairing the lens so I could use it on my other Pentax bodies. Since it's coated, probably just leave it alone and enjoy my dad's "personal touch"!

Cheers!

**DWS1** · 12-17-2020, 06:18 PM - **1 Like**

Welcome, you will find very friendly folks here.

**pentaxus** · 12-18-2020, 11:04 AM - **1 Like**

Have you tried cleaning the lens with regular lens cleaner? I know that this will make people crazy, but for certain situations it is recommended to clean a lens with acetone. Try a little on a swab and rub the finger print. That being said, I have seen the acid oils in finger prints permanently etch glass.

stevebrot · 12-18-2020, 04:41 PM - **1 Like**

Originally posted by pentaxus

I know that this will make people crazy, but for certain situations it is recommended to clean a lens with acetone.

No, not crazy, just apt to include a caution. Acetone will erode many plastics, including those used in camera optics. I have an otherwise pristine Yashica rangefinder camera where a previous owner used acetone as a solvent in proximity to the viewfinder/rangefinder parts at some time. Both are hopelessly crazed by exposure to the vapors. I won't let acetone near my camera repair/cleaning stuff or cameras.

Rather than acetone, dilute dish soap might be effective by multiple gentle (dabbing) applications to loosen and lift the print. The coatings on Super Taks are pretty robust and would not be bothered by such. That said, your sober caution regarding etching of the glass or coatings from acids and oils in the print itself is sadly very possible. Let's hope that is not the case.

Steve

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Firmware Ver: 1.00 vs Ver: 1.02 ?	Dewman	Troubleshooting and Beginner Help	5	06-15-2018 04:28 AM
For Sale - Sold: K20D w/Katz Eye, SMC Takumar 135/2.5 (Ver 2), Super Takumar 105/2.8	kenafein	Sold Items	16	04-02-2012 11:41 AM
vivitar series 1 70-210mm ver 1 vs ver 2?	ripit	Pentax SLR Lens Discussion	6	02-09-2012 05:35 PM
K20D Firmware Ver - Pentax Web Site Ver?	ChipB	Pentax DSLR Discussion	2	02-23-2010 04:14 PM
Super Takumar vs SMC Takumar Coatings	drewdlephone	Pentax SLR Lens Discussion	20	12-31-2009 04:40 PM

12-17-2020, 09:55 AM	#1
Kurt_S New Member Join Date: Jul 2017 Posts: 68	Lens coatings on Super-Takumar 55mm F2 (ver. 2 early) ?? I have my dad's broken Pentax SV and a couple of M42 lenses. One lens is badly battered, but may be worth some effort to restore (sentimentally). It is the Super-Takumar 55mm F2 (ver. 2 early), as described in the forum lens reviews. A couple bits of info are not listed on the lens page, hoping that someone can answer from their knowledge or experience. 1. Were there any optical coatings on this lens? 2. Are there any thoriated elements in this lens? SMC/Super-/Auto-Takumar 55mm F2 Reviews - M42 Screwmount Normal Primes - Pentax Lens Reviews & Lens Database Many thanks! Kurt

12-17-2020, 10:03 AM - 1 Like	#2
GUB Loyal Site Supporter Join Date: Aug 2012 Location: Wanganui Photos: Gallery \| Albums Posts: 5,760	Yes to both

12-17-2020, 10:17 AM - 1 Like	#3
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by Kurt_S I have my dad's broken Pentax SV and a couple of M42 lenses. One lens is badly battered, but may be worth some effort to restore (sentimentally). It is the Super-Takumar 55mm F2 (ver. 2 early), as described in the forum lens reviews. A couple bits of info are not listed on the lens page, hoping that someone can answer from their knowledge or experience. 1. Were there any optical coatings on this lens? 2. Are there any thoriated elements in this lens? SMC/Super-/Auto-Takumar 55mm F2 Reviews - M42 Screwmount Normal Primes - Pentax Lens Reviews & Lens Database Many thanks! Kurt Definite yes to #1 and possibly no to #2. The earliest versions of the ST 55/1.8 and ST 55/2.0 don't have thoriated glass, the later versions all do. There is a serial number range that I don't recall at this moment. The rule of thumb is that yellowing of the glass itself (not the reflection from the coating) is strong indication of a lens with one or more thoriated elements. Look through the lens at a sheet of white paper in natural light and compare the appearance to what you see with your eyes alone. If it looks yellowish/brownish through the lens, it is likely thoriated. Steve (...owns both thoriated and non-thoriated versions of the ST 55/1.8...)

12-17-2020, 11:34 AM - 1 Like	#4
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	BTW... Welcome to the Pentax Forums! Steve

12-17-2020, 02:50 PM	#5
Kurt_S New Member Join Date: Jul 2017 Posts: 68 Original Poster	Thank you, Steve and GUB. I asked because my dad made his living by building custom cars. He got his hands dirty all the time - oftentimes with solvents. It looks like he accidentally left a thumbprint on the front element! I'll keep the camera/lens for the memories (he engraved his name on the camera). I was just trying to decide if it was worth repairing the lens so I could use it on my other Pentax bodies. Since it's coated, probably just leave it alone and enjoy my dad's "personal touch"! Cheers!

12-17-2020, 06:18 PM - 1 Like	#6
DWS1 Site Supporter Join Date: Aug 2018 Location: Arkansas, USA Posts: 1,169	Welcome, you will find very friendly folks here.

12-18-2020, 11:04 AM - 1 Like	#7
pentaxus Site Supporter Join Date: Jun 2010 Location: Central Coast, CA Posts: 1,320	Have you tried cleaning the lens with regular lens cleaner? I know that this will make people crazy, but for certain situations it is recommended to clean a lens with acetone. Try a little on a swab and rub the finger print. That being said, I have seen the acid oils in finger prints permanently etch glass.

12-18-2020, 04:41 PM - 1 Like	#8
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by pentaxus I know that this will make people crazy, but for certain situations it is recommended to clean a lens with acetone. No, not crazy, just apt to include a caution. Acetone will erode many plastics, including those used in camera optics. I have an otherwise pristine Yashica rangefinder camera where a previous owner used acetone as a solvent in proximity to the viewfinder/rangefinder parts at some time. Both are hopelessly crazed by exposure to the vapors. I won't let acetone near my camera repair/cleaning stuff or cameras. Rather than acetone, dilute dish soap might be effective by multiple gentle (dabbing) applications to loosen and lift the print. The coatings on Super Taks are pretty robust and would not be bothered by such. That said, your sober caution regarding etching of the glass or coatings from acids and oils in the print itself is sadly very possible. Let's hope that is not the case. Steve