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12-24-2009, 03:21 PM   #16
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QuoteOriginally posted by wallyb Quote
... "Auto-aperture" in Pentax terminology refers to A-mount and newer lenses, with electrical contacts...
Says who?

Steve

(End of my role in this thread hijack...)

12-24-2009, 03:29 PM   #17
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QuoteOriginally posted by stevebrot Quote
QuoteQuote:
... "Auto-aperture" in Pentax terminology refers to A-mount and newer lenses, with electrical contacts...
Says who?

Steve

(End of my role in this thread hijack...)
Pentax Corporation themselves, for one...

QuoteQuote:
Pentax K-mount, M-series and S (screw) mount lenses without auto-aperture control (an A setting on the aperture ring) can be used in Manual exposure mode using stop-down metering and manual focus.
http://support.pentaximaging.com/nav/1

Or does a 50+ year old company who made most of the screwmount bodies and lenses in the first place some how also go against 'conventional wisdom of camera users everywhere'....
12-24-2009, 06:22 PM   #18
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QuoteOriginally posted by wallyb Quote
Steve, you're writing a whole lot about nothing. There's absolutely nothing to "disagree" with. "Auto-aperture" in Pentax terminology refers to A-mount and newer lenses, with electrical contacts. Since we are on PentaxForums.com and not VintageCameraInfo.com, there is no need to try to "correct" OP's already proper use of the term "auto-aperture" to refer to KA, F, FA, and DA Pentax lenses.

Period. I'm not trying to change any terminology. I'm not trying to "fight conventional wisdom and camera users", or any other heroic statements you'd like to add to your faulty cause. The terminology is already there, and it means 100% exactly what I say it means in the context of OP's posts. What do you think "A" in the A-series of lenses stands for? By your writing, it fairly evident that you don't understand what a KA lens is or how it functions, and that you are stuck in an era before then. There's no relevance to OP's concern in any of what you've written.

Further, your entire writing style is schizophrenic as you're agreeing with me here:


And you are also simply wrong here (as well as in other places):

because exposure information of KA and newer lenses is stored in an IC inside the lens, and transmitted to the camera. We're not talking about aperture linkage, we're talking about full automatic aperture control, and you're missing that point entirely.
Yet the forum description is (emphasis added):

"Pentax SLR Lens Discussion
Discuss any Pentax K-mount, screwmount, or medium format SLR lens, as well as filters and attachments."

from: Lenses and Accessories - PentaxForums.com

Personally, in my opinion, the "schizophrenic" judgement comment is uncalled for and abusive, however I respect your opinions otherwise.
12-24-2009, 07:00 PM   #19
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QuoteOriginally posted by rhodopsin Quote
mmmm...I'm fairly certain the 135/2.5 lenses are indeed auto-aperture; the aperture is operated by a pin on the mount end -- not electronic, but mechanical.

The second version S-M-C (6 elements/6 groups, first was 5/4) is an excellent lens, highly sought after...
Yes, if it was an SMC I'd probably be keeping it as opposed to selling it. The 135/2.5 Tak has a lever to operate the aperture, not a pin. Unless we are talking about the same thing?
QuoteOriginally posted by stevebrot Quote
...When evaluating a lens, you should examine the auto aperture motion (flick the lever or depress the pin) at all apertures...


12-24-2009, 10:03 PM   #20
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QuoteOriginally posted by rhodopsin Quote
Yet the forum description is (emphasis added):

"Pentax SLR Lens Discussion
Discuss any Pentax K-mount, screwmount, or medium format SLR lens, as well as filters and attachments."
Yes, and? How does that conflict with anything I've said?
QuoteOriginally posted by rhodopsin Quote
Personally, in my opinion, the "schizophrenic" judgement comment is uncalled for and abusive, however I respect your opinions otherwise.
How is a comment about someone's writing "abusive"? You can't "abuse" words, they're inanimate. It's the first word I was able to think of that described saying multiple conflicting viewpoints in successive sentences, and believing they are actually congruous. I wasn't calling *him* schizophrenic, just his train of thought in this subject. You're being a bit too melodramatic...
12-24-2009, 10:33 PM   #21
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QuoteOriginally posted by builttospill Quote
Yes, if it was an SMC I'd probably be keeping it as opposed to selling it. The 135/2.5 Tak has a lever to operate the aperture, not a pin. Unless we are talking about the same thing?
The lever you're speaking of controls between A and M mode on the lens, which is how you switch between wide open and stopped down on an adapted camera like your digital one, in order to achieve some slight analogue of a regular lens that you would use wide-open metering on. However, on the rear of the lens near the screw threads, you will see a very small little pin. You can actually put the lens into A mode and set an aperture (lower than wide-open), and depress the pin with your finger and the blades will stop down. This was used on screwmount cameras to couple the lens' aperture assembly with the body to allow use of wide-open metering on screwmount bodies, or "auto-aperture" control.

However, as you know personally, with the introduction of Pentax KA lenses in the 80s, this is now the archaic and less common usage, especially on this site, since the KA series and newer lenses have a newer kind of automatic aperture control through contacts that interface with the body electronically. The screwmount "auto-aperture" definition is completely incompatible with all non-screwmount bodies. And again, specifically in Pentax where there was a line of auto-aperture lenses before AF lenses, unlike how it was with most other manufacturers, it is important to always use the newer (as in, 30 year-old instead of 50 year old) definition of the term to avoid further confusion.

Which wasn't done in this thread... at all...
12-25-2009, 08:00 AM   #22
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QuoteOriginally posted by wallyb Quote
Yes, and? How does that conflict with anything I've said?
Discussion is not limited to KA and newer lenses.

The auto-aperture designation is context-sensitive; auto-aperture when discussing M42 Screwmount lenses has a different meaning from auto-aperture used with KA and newer lenses. This thread is about an M42 Super-Takumar, where auto-aperture refers to the mechanical linkage.

similar confusion must exist among newer Pentax users regarding M42 Auto-Takumars. Context is important to know when the term "auto" is used.

QuoteOriginally posted by wallyb Quote
How is a comment about someone's writing "abusive"? You can't "abuse" words, they're inanimate. It's the first word I was able to think of that described saying multiple conflicting viewpoints in successive sentences, and believing they are actually congruous. I wasn't calling *him* schizophrenic, just his train of thought in this subject. You're being a bit too melodramatic...

you wrote:

QuoteOriginally posted by wallyb Quote
... your entire writing style is schizophrenic ...
given the negative connotations of the word, that appears to be a blanket condemnation, which after further explanation, you obviously did not intend.

perhaps we are both "being a bit too melodramatic"? You have a strong conviction regarding the use of "auto-aperture", and while I agree with your thoughful, intelligent, and well-documented distinction and proposed correction, usage and context remains an important consideration, even though there may be confusion among folks who are only familiar with the modern usage. Maybe not; I doubt any newbie would think an old M42 Auto-Takumar could have electronics usable with modern body.

BTW, the link http://support.pentaximaging.com/nav/1 doesn't work (server down?)
12-25-2009, 08:39 AM   #23
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QuoteOriginally posted by rhodopsin Quote
Discussion is not limited to KA and newer lenses.

The auto-aperture designation is context-sensitive
You're right, and when the OP used the term, he was clearly referring to KA and newer lenses. That's the whole point. Period.

QuoteOriginally posted by rhodopsin Quote
given the negative connotations of the word, that appears to be a blanket condemnation, which after further explanation, you obviously did not intend.
I did not feel that the word had any connotations that were inherently inappropriate to my usage of it. Any appearance of the word is up to your interpretation, and does not have any necessary relation to my intended usage, nor necessarily the definition of the word itself.

As a general rule of thumb, it's best to not jump to the most negative meaning of a word or phrase, in order to save face and not devolve into explanatory conversations like this.

QuoteOriginally posted by rhodopsin Quote
perhaps we are both "being a bit too melodramatic"? You have a strong conviction regarding the use of "auto-aperture", and while I agree with your thoughful, intelligent, and well-documented distinction and proposed correction, usage and context remains an important consideration, even though there may be confusion among folks who are only familiar with the modern usage. Maybe not; I doubt any newbie would think an old M42 Auto-Takumar could have electronics usable with modern body.
I would disagree, since all of my well-documented-and-thoughtful-information-that-is-only-relevant-in-certain-context was in that context. It is clear that OP was speaking in the context that I continued the conversation in, the context of KA and newer lenses, and other people in the thread chose to derail it with an archaic usage of the term, and in some cases blatant misinformation. The OP does not need to be aware of that archaic usage in order to help is problems. On the contrary, it would be assumed that it would only serve to add to OP's confusion. The tone with which it was explained did not add anything to the conversation, so I pointed that out. I was then given a very melodramatic and over the top reply about how I am ignoring conventional wisdom and camera lovers anywhere, or something equally ignorant, so I made sure to correct the parts that needed correction. It's that simple.

And the site takes a while to load.

12-25-2009, 09:18 AM   #24
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@wallyb: in message #21, builttospill is the OP, the lens he is/was referring to is a Super-Takumar 135/2.5
12-25-2009, 09:56 AM   #25
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QuoteOriginally posted by rhodopsin Quote
@wallyb: in message #21, builttospill is the OP, the lens he is/was referring to is a Super-Takumar 135/2.5
In message #6 (I don't know why you're referencing #21), he's saying the screwmount 135/2.5 is not auto-aperture, as in it's not a KA or newer lens, and it needs to be used with stop-down metering on an adapted body, so the blades having some oil on them are not a big concern, since the aperture control is done manually by hand, since it's not auto-aperture like he is referring to. Are you really serious that you don't get something that simple?
12-25-2009, 10:09 AM   #26
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is that in the marketplace or forum guidelines someplace, the definition of auto-aperture?
12-25-2009, 10:30 AM   #27
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QuoteOriginally posted by rhodopsin Quote
is that in the marketplace or forum guidelines someplace, the definition of auto-aperture?
It's becoming apparent that you're being this obtuse on purpose. Pentax themselves define auto-aperture the same way I do. There's no point in continuing with this discussion; all the facts are present for you to read.

http://74.125.93.132/search?q=cache:uG5_HzyXpVwJ:support.pentaximaging.com/n...&ct=clnk&gl=us
12-25-2009, 11:02 AM   #28
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QuoteOriginally posted by wallyb Quote
It's becoming apparent that you're being this obtuse on purpose. Pentax themselves define auto-aperture the same way I do. There's no point in continuing with this discussion; all the facts are present for you to read.

http://74.125.93.132/search?q=cache:uG5_HzyXpVwJ:support.pentaximaging.com/n...&ct=clnk&gl=us
Nope only searching for documentation. I get your point now: Asahi used the term "auto diaphram" during screwmount era; we knew what we were talking about but not the OP when I wrote auto aperture. Thank you.
12-29-2009, 11:12 AM   #29
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Just to clarify. The lens I recently purchased and have been using it with my MX is a Takumar 135mm f/2.5. Sorry if I wasn't more clear, but it's not M42, it's not a Super. It's a bayonet mount single-coated Tak. It's here in the Lens Review section.

It's not a KA mount as there is no Automatic Aperture setting on the lens and it's not an SMC-A which fits under the KA mounts. It doesn't quite fit under the K-Mount either because it's not an SMC or SMC-M lens. It's just a single-coated Takumar bayonet mount if that helps. I have used it with my K10D, MX and K1000.

Edit: I would have mentioned this earlier, but I've been busy with the holiday, and took a break from the forum. (It's always interesting to come back and see what you've missed!) I didn't realize there were so many 135's produced over the years.

Last edited by builttospill; 01-05-2010 at 10:38 AM.
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