Super Takumar 55mm f/1.8 question

el baroda · 09-01-2015, 02:08 AM

Hi. I received my copy of a Super Takumar 55mm f/1.8 lens and a genuine Pentax M42 to PK adapter last week. I have made the following observations which I would like you to comment on:

1. The lens works only on manual mode. I set the lens switch to manual and select the aperture opening that I want. The viewfinder darkens accordingly, and the shots are properly exposed. When I move the switch to auto, the lens remains open when I take a shot. The photos are always way overexposed regardless of the aperture setting. I notice that there is a pin on the lens mount. I think this is supposed to be tripped when the shutter is pressed so that the aperture closes down. This obviously does not happen here. Am I right in assuming that the pin only works when the lens is mounted on a Spotmatic, and not on a DSLR?

2. The genuine M42 adapter does not lock in place. I see no springs on it. When I remove the lens, the adapter comes off with it. Is the adapter defective?

Your early comments and suggestions will be greatly appreciated.

Thank you and kind regards.

Adam · 09-01-2015, 02:33 AM

Originally posted by el baroda

1. The lens works only on manual mode.

Yup the diaphragm must be set to manual as the camera cannot stop the lens down on its own. Since the viewfinder darkens, you can actually use Av mode without any issues also.

Originally posted by el baroda

2. The genuine M42 adapter does not lock in place. I see no springs on it. When I remove the lens, the adapter comes off with it. Is the adapter defective?

Either defective nor not installed properly. Did you mount the adapter on the camera before attaching the lens?

Not a Number · 09-01-2015, 03:04 AM

Originally posted by el baroda

2. The genuine M42 adapter does not lock in place. I see no springs on it. When I remove the lens, the adapter comes off with it. Is the adapter defective?

If you bought the adapter second hand one of the previous owners may have removed the spring on purpose. Some people do this and attach the ring semi-permanently with a thread locker on lens they use quite often. Or the spring may have broken and was removed for that reason. Contact the person you bought it from and see if they still have the spring and retaining screw.

If you bought it new it should have a spring on it near the red dot. If it doesn't see if you can return it for a replacement.

el baroda · 09-01-2015, 03:05 AM

Originally posted by Adam

Yup the diaphragm must be set to manual as the camera cannot stop the lens down on its own. Since the viewfinder darkens, you can actually use Av mode without any issues also.

Either defective nor not installed properly. Did you mount the adapter on the camera before attaching the lens?

Yes, Adam, I mounted the adapter on the camera. I read an old thread here just a minute ago and I noted that there should be a locking spring on the adapter. My copy does not have any spring at all, so there lies the problem. Thank you for your help.

---------- Post added 09-01-2015 at 08:07 PM ----------

Originally posted by Not a Number

If you bought the adapter second hand one of the previous owners may have removed the spring on purpose. Some people do this and attach the ring semi-permanently with a thread locker on lens they use quite often. Or the spring may have broken and was removed for that reason. Contact the person you bought it from and see if they still have the spring and retaining screw.

If you bought it new it should have a spring on it near the red dot. If it doesn't see if you can return it for a replacement.

I contacted the seller just now. Thanks for your help.

reeftool · 09-02-2015, 06:59 PM

I pretty much just leave my camera set to Av when I'm shooting with any of my Taks. If you use it a lot, it's quite simple to focus with the switch in auto and move it to manual and take the shot. My 55/1.8 is one of my favorite lenses.

09-01-2015, 02:08 AM	#1
el baroda Inactive Account Join Date: May 2010 Location: Sydney Photos: Albums Posts: 217	Super Takumar 55mm f/1.8 question Hi. I received my copy of a Super Takumar 55mm f/1.8 lens and a genuine Pentax M42 to PK adapter last week. I have made the following observations which I would like you to comment on: 1. The lens works only on manual mode. I set the lens switch to manual and select the aperture opening that I want. The viewfinder darkens accordingly, and the shots are properly exposed. When I move the switch to auto, the lens remains open when I take a shot. The photos are always way overexposed regardless of the aperture setting. I notice that there is a pin on the lens mount. I think this is supposed to be tripped when the shutter is pressed so that the aperture closes down. This obviously does not happen here. Am I right in assuming that the pin only works when the lens is mounted on a Spotmatic, and not on a DSLR? 2. The genuine M42 adapter does not lock in place. I see no springs on it. When I remove the lens, the adapter comes off with it. Is the adapter defective? Your early comments and suggestions will be greatly appreciated. Thank you and kind regards.

09-01-2015, 02:33 AM	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,595	Originally posted by el baroda 1. The lens works only on manual mode. Yup the diaphragm must be set to manual as the camera cannot stop the lens down on its own. Since the viewfinder darkens, you can actually use Av mode without any issues also. Originally posted by el baroda 2. The genuine M42 adapter does not lock in place. I see no springs on it. When I remove the lens, the adapter comes off with it. Is the adapter defective? Either defective nor not installed properly. Did you mount the adapter on the camera before attaching the lens? Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

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09-01-2015, 03:04 AM	#3
Not a Number Moderator Join Date: Mar 2012 Location: Venice, CA Posts: 10,526	Originally posted by el baroda 2. The genuine M42 adapter does not lock in place. I see no springs on it. When I remove the lens, the adapter comes off with it. Is the adapter defective? If you bought the adapter second hand one of the previous owners may have removed the spring on purpose. Some people do this and attach the ring semi-permanently with a thread locker on lens they use quite often. Or the spring may have broken and was removed for that reason. Contact the person you bought it from and see if they still have the spring and retaining screw. If you bought it new it should have a spring on it near the red dot. If it doesn't see if you can return it for a replacement.

09-01-2015, 03:05 AM	#4
el baroda Inactive Account Join Date: May 2010 Location: Sydney Photos: Albums Posts: 217 Original Poster	Originally posted by Adam Yup the diaphragm must be set to manual as the camera cannot stop the lens down on its own. Since the viewfinder darkens, you can actually use Av mode without any issues also. Either defective nor not installed properly. Did you mount the adapter on the camera before attaching the lens? Yes, Adam, I mounted the adapter on the camera. I read an old thread here just a minute ago and I noted that there should be a locking spring on the adapter. My copy does not have any spring at all, so there lies the problem. Thank you for your help. ---------- Post added 09-01-2015 at 08:07 PM ---------- Originally posted by Not a Number If you bought the adapter second hand one of the previous owners may have removed the spring on purpose. Some people do this and attach the ring semi-permanently with a thread locker on lens they use quite often. Or the spring may have broken and was removed for that reason. Contact the person you bought it from and see if they still have the spring and retaining screw. If you bought it new it should have a spring on it near the red dot. If it doesn't see if you can return it for a replacement. I contacted the seller just now. Thanks for your help.

09-02-2015, 06:59 PM	#5
reeftool Pentaxian Join Date: Dec 2007 Location: Upstate New York Photos: Gallery \| Albums Posts: 9,554	I pretty much just leave my camera set to Av when I'm shooting with any of my Taks. If you use it a lot, it's quite simple to focus with the switch in auto and move it to manual and take the shot. My 55/1.8 is one of my favorite lenses.