Fungus advice please

ShutterPro · 04-29-2022, 01:56 PM

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Hello,
Just got a 135mm f2.5 Bayonet. Actually went for the smc K version, but accidentally bought this one instead - for the price of a K. It is in top mint condition, and just by chance I spotted some fungus on the rear element (is it really fungus?). Now I am trying to decide whether to keep it or not. I wanted the K for portraits and wide-open aperture landscape and architecture work. Can the Bayonet infect my other glass? I own several lenses, most of which are vintage. Or should I send it back and try again, this time for a real smc lens?
Thanks for any tips and advice in advance!
Jan

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steephill · 04-29-2022, 02:01 PM

Send it back. I take it you bought one of these - Takumar 135/2.5 (Bayonet) | The K-Mount Page It should be much cheaper than the superior K series 135/f2.5.

ShutterPro · 04-29-2022, 02:29 PM

Originally posted by steephill

Send it back. I take it you bought one of these - Takumar 135/2.5 (Bayonet) | The K-Mount Page It should be much cheaper than the superior K series 135/f2.5.

Yeah, it is that lens I got...

**UncleVanya** · 04-30-2022, 04:50 AM

The lens you got is very inexpensive. Look on eBay as an example: Vintage Takumar (Bayonet) 135mm F/2.5* Lens (Pentax K Mount) | eBay

**photogem** · 04-30-2022, 10:58 PM

I never had the bayonet-version of this lens but observed that there are quite a few who really like it:
Takumar 135mm F2.5 Bayonet Reviews - Non-SMC Pentax Prime Lenses - Pentax Lens Reviews & Lens Database

Nevertheless, fungus is not acceptable and I think a return is obligatory.

Usually the original heavy Takumars 135/2,5 sell higher but there are different versions, the Super Takumar (5 Element)
the Super Multi Coated Version I with 5 Elements and Version 2 with 6 Elements, same optical design as the highly desired
SMC Pentax K 135/2,5 (which I still have and use sometimes)

I never had any of the earlier 5 Element versions.

It is said that a 135mm lens is the easiest to construct and yet, I found the early K135/2,5 betters the more expensive A135/2,8

But my very favourite is the F135/2,8, a really fantastic lens.

ShutterPro · 05-01-2022, 09:31 AM

Originally posted by photogem

I never had this lens but observed that there are some who really like it:
Takumar 135mm F2.5 Bayonet Reviews - Non-SMC Pentax Prime Lenses - Pentax Lens Reviews & Lens Database
Nevertheless, fungus is not acceptable and a return obligatory.

Usually the original heavy Takumar 135/2,5 sell higher, but there are different versions, the Super Takumar (5 Element)
the Super Multi Coated Version I with 5 Elements and Version 2 with 6 Elements, same optical design as the highly desired

SMC Pentax K 135/2,5 (which I still have and use sometimes)

I never had any of the earlier 5 Element versions somehow a 135mm lens is the easiest to construct and yet, I found the
K135/2,5 betters the more expensive A135/2,8
My very favourite is the F135/2,8, a fantastic lens.

Thank you. I have contacted the seller, so let's see. And, as a matter of fact, I have found a real K version for a good price locally, so let's see how everything turns out.

04-30-2022, 10:58 PM	#5
photogem Site Supporter Join Date: Apr 2015 Posts: 3,522	I never had the bayonet-version of this lens but observed that there are quite a few who really like it: Takumar 135mm F2.5 Bayonet Reviews - Non-SMC Pentax Prime Lenses - Pentax Lens Reviews & Lens Database Nevertheless, fungus is not acceptable and I think a return is obligatory. Usually the original heavy Takumars 135/2,5 sell higher but there are different versions, the Super Takumar (5 Element) the Super Multi Coated Version I with 5 Elements and Version 2 with 6 Elements, same optical design as the highly desired SMC Pentax K 135/2,5 (which I still have and use sometimes) I never had any of the earlier 5 Element versions. It is said that a 135mm lens is the easiest to construct and yet, I found the early K135/2,5 betters the more expensive A135/2,8 But my very favourite is the F135/2,8, a really fantastic lens. Last edited by photogem; 05-01-2022 at 10:29 AM.

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04-29-2022, 02:01 PM	#2
steephill Pentaxian Join Date: Nov 2018 Photos: Albums Posts: 590	Send it back. I take it you bought one of these - Takumar 135/2.5 (Bayonet) \| The K-Mount Page It should be much cheaper than the superior K series 135/f2.5.

04-29-2022, 02:29 PM	#3
ShutterPro Veteran Member Join Date: Dec 2020 Posts: 389 Original Poster	Originally posted by steephill Send it back. I take it you bought one of these - Takumar 135/2.5 (Bayonet) \| The K-Mount Page It should be much cheaper than the superior K series 135/f2.5. Yeah, it is that lens I got...

04-30-2022, 04:50 AM	#4
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,459	The lens you got is very inexpensive. Look on eBay as an example: Vintage Takumar (Bayonet) 135mm F/2.5* Lens (Pentax K Mount) \| eBay

05-01-2022, 09:31 AM	#6
ShutterPro Veteran Member Join Date: Dec 2020 Posts: 389 Original Poster	Originally posted by photogem I never had this lens but observed that there are some who really like it: Takumar 135mm F2.5 Bayonet Reviews - Non-SMC Pentax Prime Lenses - Pentax Lens Reviews & Lens Database Nevertheless, fungus is not acceptable and a return obligatory. Usually the original heavy Takumar 135/2,5 sell higher, but there are different versions, the Super Takumar (5 Element) the Super Multi Coated Version I with 5 Elements and Version 2 with 6 Elements, same optical design as the highly desired SMC Pentax K 135/2,5 (which I still have and use sometimes) I never had any of the earlier 5 Element versions somehow a 135mm lens is the easiest to construct and yet, I found the K135/2,5 betters the more expensive A135/2,8 My very favourite is the F135/2,8, a fantastic lens. Thank you. I have contacted the seller, so let's see. And, as a matter of fact, I have found a real K version for a good price locally, so let's see how everything turns out.