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05-02-2018, 04:46 AM   #1
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So what's the deal with this Takumar 135mm/2.5 I got?

Hey chaps (and gals),

So today my Takumar 135mm/2.5 (Bayonet) arrived having purchased it effortlessly from forum member blumoon722 (fantastic chap to deal with and swift sale process... how does one actually give stars and whatnots to forum members who done good?).

Anyway, loving the piece of glass! I am however needing advice or confirmation for the proper use of this style of old glass, as my only current experience to date with old glass are the Pentax lenses with 'A' meaning I can control aperture from within the camera body when the lens is placed in the A position.

This lens don't have that (I knew that when going in for the buy), but it seems I'm a little more handicapped for shooting with it than I first thought.

1) I thought that the aperture might still be displayed on screen but I see that's not the case. Can the EXIF ever know the aperture the shot was taken at?

2) I thought being in Av mode etc, I might be able to just toggle the aperture on the lens and snap away, but I realise that changing the aperture in Av mode doesn't impact the shot at all, it's still registering as wide open. I mean it's still fine, it works in all other regards the way I like, Auto ISO and a shutter speed that never dips below a point I'm uncomfortable shooting with... it's just always gonna take the shot at f2.5 (hey that's alright, it's really quite sharp at it's widest anyway!).

3) So you have to be in Manual mode to get the camera to recognise aperture changes, there's a lot more spamming of the green button after an aperture change to give you some kind of starting point for the shot huh...

4) Can we do interesting and funky things with that green button then in Manual mode? For example... when I use Av mode with my lenses I have Auto ISO on (durr...) and specifiy an ISO limit perhaps to something like 6400. Then in menu 1>ISO AUTO Settings>AUTO ISO Parameters I change from Slow, Normal and Fast depending upon the situation, but what this kinda ends up meaning for Av mode is that my shutter speed doesn't drop down below a certain shutter speed that I feel comfortable with for that given situ. Can we at all be in Manual Mode and change the aperture on the lens, and then whilst lining up the camera at the scene, press the green button and get something similar to occur to like what I outlined above? Cuz what I'm getting with Manual Mode currently is kinda the opposite of what I want. I get a fixed aperture (as determined and controlled by me on the lens, dat's cool and fine), but then there's no Auto ISO and so you have to determine the ISO first and then the green button pretty much dictates the shutter speed only (basically in Manual mode the aperture and iso are fixed, green button only messes with the shutter speed).
We can't turn it around at all can we, have the green button adjust the ISO and keep the Shutter speed fixed?
I think my ideal 'mode' to use with this lens would be something to mimic Av mode, in that I choose the aperture, have ISO fluctuate with the press of the green button, and have shutter speed behave (basically something like 1/125 and let the ISO fall where it may, and if it's bright conditions and I'm shooting wider etc then I would scroll the Front Dial to boost the shutter speed till it stopped blinking. I just find using the thumb wheel to adjust ISO (if the other dial with the different things to toggle on and off like ISO, HDR, +/- etc is set to 'ISO') a little more awkward. And I hate reaching or looking to press the ISO button and then using a dial...
Picky aren't I!
Hey wait... didn't I just outlike TAv mode? lol

Ach... here's some shots I fired off today with the old glass; Post your K-1 pictures! - Page 1066 - PentaxForums.com

05-02-2018, 04:55 AM - 1 Like   #2
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for K mount lenses without the A position, you need to modify your camera settings, depending on model there is a setting "use aperture ring" which needs to be enabled. this will allow you to have the camera close the aperture down when shooting.

to meter, and again this depends on model, you need to do one of the following with the camera in manual mode.
- to get the exposure use optical depth of field preview, this will give you a +/- for the exposure like the old film camera matched needle systemd
- to set exposure, i am only familiar with cameras that have a Green Button. press it in manual mode and it will set the shutter to be what is required for exposure, based upon the selected aperture and iso values.

Av mode only shoots wide open regardless of setting, but will modify shutter and or ISO if auto iso selected to give you a correct wide open exposure.

note, what i do with the green button and manual lenses is find a surface that is medium grey, in the scene that i am shooting, and set the exposure to that surface, and then just shoot away and only change exposure when the situation changes. you can set your image preview to show the histogram, and if you shoot and check histogram periodically you will not have an issue

a word of advice, the takumar bayonette is prone to flare due to its inferior coarings, get a good lens hood and your contrast and image quality will improve greatly
05-02-2018, 05:00 AM - 2 Likes   #3
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Everything you need to know is here...

How to use/meter Manual & M42 Lenses on all Pentax DSLRs (K-1, K-3, K-5, K-30, etc) - PentaxForums.com
05-02-2018, 05:13 AM   #4
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QuoteOriginally posted by k0og Quote
Thanks, so is the Takumar 135mm/2.5 (Bayonet) considered a 'M42' lens? I thought it was a K Mount (just without the A setting) and that perhaps M42 lenses required an K Mount adapter to attach to a (newer) Pentax release body. Am I mistaken here?

QuoteOriginally posted by Lowell Goudge Quote
for K mount lenses without the A position, you need to modify your camera settings, depending on model there is a setting "use aperture ring" which needs to be enabled. this will allow you to have the camera close the aperture down when shooting.

to meter, and again this depends on model, you need to do one of the following with the camera in manual mode.
- to get the exposure use optical depth of field preview, this will give you a +/- for the exposure like the old film camera matched needle systemd
- to set exposure, i am only familiar with cameras that have a Green Button. press it in manual mode and it will set the shutter to be what is required for exposure, based upon the selected aperture and iso values.

Av mode only shoots wide open regardless of setting, but will modify shutter and or ISO if auto iso selected to give you a correct wide open exposure.

note, what i do with the green button and manual lenses is find a surface that is medium grey, in the scene that i am shooting, and set the exposure to that surface, and then just shoot away and only change exposure when the situation changes. you can set your image preview to show the histogram, and if you shoot and check histogram periodically you will not have an issue

a word of advice, the takumar bayonette is prone to flare due to its inferior coarings, get a good lens hood and your contrast and image quality will improve greatly
Yeah so it sounds as if I have everything working as best as I really can. I knew about that Custom Menu 4>Use Aperture Ring setting, I had enabled mine already before (for some strange reason), with this lens attached, if I disable it then the camera refuses to take a picture?!

I will try that optical depth preview thing, I was actually using it a fair bit earlier in the month when practising MF with other glass.

By chance can you recommend a good hood? With the naff coating is it wise to whack some kind of voodoo filter on as well to assist? CPL? Don't these increase saturation and contrast?

05-02-2018, 05:35 AM   #5
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QuoteOriginally posted by BruceBanner Quote
hanks, so is the Takumar 135mm/2.5 (Bayonet) considered a 'M42' lens? I thought it was a K Mount (just without the A setting) and that perhaps M42 lenses required an K Mount adapter to attach to a (newer) Pentax release body. Am I mistaken here?
Yes and No.
M42 are lenses with a screw mount attachment. Bayonet have the 1/4 turn attachment.

All of the M42 and Some of the early K-Mount (bayonet) do not have contacts that report lens information to the camera.

This talks about the different K-Mount standards. M42 is fully manual and older then K.

https://www.pentaxforums.com/articles/photo-articles/evolution-of-pentax-k-mount.html
05-02-2018, 05:45 AM   #6
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QuoteOriginally posted by BruceBanner Quote
Thanks, so is the Takumar 135mm/2.5 (Bayonet) considered a 'M42' lens? I thought it was a K Mount (just without the A setting) and that perhaps M42 lenses required an K Mount adapter to attach to a (newer) Pentax release body. Am I mistaken here?



Yeah so it sounds as if I have everything working as best as I really can. I knew about that Custom Menu 4>Use Aperture Ring setting, I had enabled mine already before (for some strange reason), with this lens attached, if I disable it then the camera refuses to take a picture?!

I will try that optical depth preview thing, I was actually using it a fair bit earlier in the month when practising MF with other glass.

By chance can you recommend a good hood? With the naff coating is it wise to whack some kind of voodoo filter on as well to assist? CPL? Don't these increase saturation and contrast?
the difference between M42 and K mount lenses is that with K mount lenses, you can focus with open aperture, and the camera (in manual mode) will stop down the lens when shooting. with M42 you need to manually stop down the lens after focusing, BUY you can shoot in Av mode and it will set the exposure to match where you have stopped down the lens.

there is a good article on using M42 and K lenses as a sticky
05-02-2018, 06:17 AM - 1 Like   #7
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QuoteOriginally posted by BruceBanner Quote
Thanks, so is the Takumar 135mm/2.5 (Bayonet) considered a 'M42' lens?

No, just the topic is also about m42 lenses. The Takumar Bayonet is a cheaper alternative to the Pentax-m lenses. No SMC coatings. But it can be considered an M-lens. So you need to use stop down metering in M-mode as described (unless you are shooting wide open, then you can also use Av mode), No aperture in exif possible as the camera doesn't now what aperture was used.

05-02-2018, 06:23 AM   #8
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With an auto aperture K-mount lens with lever and no contacts you can shoot in Av mode. However it will only meter and shoot wide open regardless of the aperture ring setting.
05-02-2018, 08:45 AM - 2 Likes   #9
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QuoteOriginally posted by BruceBanner Quote
1) I thought that the aperture might still be displayed on screen but I see that's not the case. Can the EXIF ever know the aperture the shot was taken at?
Nope F--- is what you get. Since the camera body is not setting the aperture, it has no idea where it is set. This was the case even with the non-crippled mount. There are some forum members who keep a detail shot log on paper or phone and enter the aperture into the EXIF manually using ExifTool.

QuoteOriginally posted by BruceBanner Quote
2) I thought being in Av mode etc, I might be able to just toggle the aperture on the lens and snap away
You can change the aperture ring position in Av mode, but there will be no stop-down to shoot with K-mount lenses having auto aperture actuation. Both meter reading and exposure are with the lens wide open. Manual aperture lenses work just fine.

QuoteOriginally posted by BruceBanner Quote
3) So you have to be in Manual mode to get the camera to recognise aperture changes, there's a lot more spamming of the green button after an aperture change to give you some kind of starting point for the shot huh...
You have to be in M, X, or B modes for auto aperture actuation to work. Again, the body knows nothing about aperture changes. The green button provides one with an exposure setting based on an instantaneous stop-down meter reading. For some fun, try the optical DOF preview in M mode. You should get an EV scale for more exacting exposure manipulation.

QuoteOriginally posted by BruceBanner Quote
4) Can we do interesting and funky things with that green button then in Manual mode?
If you find any, let me know. It pretty much just does a momentary stop-down to adjust the shutter speed.

I don't have a K-1 and can't vouch for whether stuff works the same as on the K-3, but here are a few observations regarding stop-down metering and non-A lenses in general on Pentax cameras:
  • Green button metering generally works OK, but can be inconsistent (meter response is often not linear). Whether the metering is off, how it is off (up or down), and how much it is off depends strongly on what lens is mounted and what aperture is being used. Chimping the histogram to evaluate/adjust exposure is highly recommended.
  • While manual aperture lenses can be used in Av mode, meter inconsistency may be somewhat worse than using them in M mode. Yes, green button metering still works with manual aperture lenses with no aperture actuator coupling.
  • Live view offers the best metering performance. If I use live view to get the exposure settings, I generally switch back to the optical viewfinder to shoot.
  • EC works for stop-down metering, though some practice is suggested first
  • My approach to stop-down metering goes back to how I did it in 1971:
    • Stop down lens to meter
    • Set exposure based on the meter reading
    • Shoot at will until either the light or subject changes (no need to meter between shots)
  • Flash is fully manual as far as the body is concerned, but that doesn't mean one must do full manual flash. Many older and even some new flash units feature a metering cell built into the flash itself. These flash are able to adjust intensity (duration actually) in real time based on ISO and aperture with no input from the body. Flash with this feature are broadly called "auto-thyristor" and they work quite well for most subjects. I have a Pentax AF280T with that feature that I use with my K-3. Note that care should be taken in regards to vintage flash and trigger voltage at the hot shoe and/or pc socket. All Pentax flash are safe, but many older 3rd-party are not.
Have fun!


Steve

Last edited by stevebrot; 05-02-2018 at 08:53 AM.
05-02-2018, 10:36 AM - 2 Likes   #10
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I have your lens' sister, the 135/2.8 Takumar Bayonet, and it has a built-in lens hood!
05-02-2018, 10:56 AM - 2 Likes   #11
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Stick it in M mode, pick an aperture and green button. Easy as pie. You'll also just get used to fiddling with shutter speed for minor adjustments, it's not very hard at all!

Great lens by the way, easily one of my favorites. I wonder if it could be considered "cult status" now?

Last edited by ZombieArmy; 05-02-2018 at 11:05 AM.
05-02-2018, 11:18 AM   #12
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I would rather stick it in M mode, pick an aperture and ISO, and hit the DoF Preview. Pay attention to the light meter "needle" level bar to see if you're over or under exposing per the camera's light meter. It works as long as you have the DoF Preview function active. I find it to be more accurate and easier to better read the scene than the green button which is just a thin slice of time.

This is made easier on the top end DSLR's with their DoF Preview function on the shutter collar. I do find that, if I've not picked up my K-5 II for a while, going to do this I end up pushing instead of pulling and turning the camera off at dumb times.
05-02-2018, 11:35 AM - 1 Like   #13
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QuoteOriginally posted by BruceBanner Quote
So today my Takumar 135mm/2.5 (Bayonet) arrived having purchased it effortlessly from forum member blumoon722 (fantastic chap to deal with and swift sale process... how does one actually give stars and whatnots to forum members who done good?).
READ FIRST: How to list items - marketplace rules - condition key - feedback guide - PentaxForums.com
05-02-2018, 01:10 PM   #14
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QuoteOriginally posted by BruceBanner Quote
Thanks, so is the Takumar 135mm/2.5 (Bayonet) considered a 'M42' lens? I thought it was a K Mount (just without the A setting) and that perhaps M42 lenses required an K Mount adapter to attach to a (newer) Pentax release body. Am I mistaken here?
It's the same as a K or M-series K-mount lens, feature-wise.

As for feedback, go to the marketplace thread where you bought the lens, and click on "leave feedback" under the seller's name. It may be in the "sold" section by now.

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05-02-2018, 02:44 PM - 1 Like   #15
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QuoteOriginally posted by stevebrot Quote
I don't have a K-1 and can't vouch for whether stuff works the same as on the K-3, but here are a few observations regarding stop-down metering and non-A lenses in general on Pentax cameras:

Green button metering generally works OK, but can be inconsistent (meter response is often not linear). Whether the metering is off, how it is off (up or down), and how much it is off depends strongly on what lens is mounted and what aperture is being used. Chimping the histogram to evaluate/adjust exposure is highly recommended.
Steve, my experience so far with the k1 and the K and M series lenses is that it meters pretty accurately at any f stop using M and grren button metering. Certainly displays none of the progressive overexposure that disappointed me when the K10D first came out.
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