Infinity focus.

[Mike Kennedy]

A fellow member just asked me if you would loose infanity focus with a Super Takumar lens mounted (with adaptor) on a k-mount Pentax.I don't know.

 

[Struan Gray]

"Infanity, n, the expletive uttered by photographers when they check the contact sheets and find they did not stop down far enough."

That said, the adapters to fit a screw mount lens on a k-mount body that I have seen all preserve infinity focus.

 

[Steve Smith]

Whilst we're being pedantic, it's lose, not loose.

Possibly the most mis-used word on the internet!



Steve.

 

[Pinholemaster]

I know infinity is around here some place. Just can't remember where I put it.

 

[DannL]

With some quick research I ran across this on eBay . . .

http://cgi.ebay.com/Pentax-ScrewMou...ryZ30059QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

I'm not going to advise that you purchase this specific item, but it is advertised to preserve focus at infinity. I assume you have a M42 mount lens. My Takumar is screw mount and with the proper adapter for a Canon AE-1 Program it actually allows me to focus beyond infinity with most lenses. My adapter is much thicker than the adapter mentioned above, and that is possible because the Canon body design is very thin.

 

[BradS]

Whilst we're being pedantic, it's lose, not loose.

Possibly the most mis-used word on the internet!

Steve.

I'd have guessed the most mis-used words on the 'net were in the set:

{effect, affect, then, than}.

 

[Dan Fromm]

Interesting. I believe Struan's right, but have gone looking for reports of different mounts' registers to see for myself. Bad move, as usual.

These two sources: http://www.mapug-astronomy.net/ragreiner/adapters.html http://www.markerink.org/WJM/HTML/mounts.htm agree that both Praktica/Pentax and K-mount registers are 45.5 mm, which makes me wonder how one can put an M42 lens on a K-mount body without losing infinity focus. Again, I believe it can be and is done, just don't understand the mechanics.

Will someone who has both flavors of body ready to hand please explain how its done?

Thanks,

Dan

 

[Nick Zentena]

Pentax designed K mount to fully take M42 lenses.

 

[Steve Smith]

I'd have guessed the most mis-used words on the 'net were in the set:

{effect, affect, then, than}.

Yes those really annoy me too. Along with accept and except. e.g. "payment by Paypal excepted".



Steve.

 

[Jon Shiu]

The screw mount adapter ring mounts fully internal to the K-mount opening, so no problems as there is no extension.

Jon

 

[juan]

How about the use of an apostrophe as a warning that an "s" is about to appear at the end of a word?
juan

Yes those really annoy me too. Along with accept and except. e.g. "payment by Paypal excepted".



Steve.

 

[winger]

How about the use of an apostrophe as a warning that an "s" is about to appear at the end of a word?

YES :rolleyes: I'm so tired of seeing things like, "He took it's picture."

The screw mount adapter ring mounts fully internal to the K-mount opening

and this is why I always get mine stuck. But no problems with infinity that I've noticed. Though I have one screwmount lens that doesn't go to infinity on its own.

 

[Dan Fromm]

Thanks, Jon.

 

[elekm]

Some M42 => K mount adapters will allow the lens to focus to infinity. Some won't. The cheaper ones won't, and you must make sure that you purchase the correct adapter.

The "official" Pentax adapter does allow lenses to focus to infinity. It drops into the lens mount and is flush with the front of the lens mount.

Adapters with the flange that sits above the lens mount don't allow a lens to focus to infinity.

By the way, the most misused word on eBay and Internet photography forums is "mint." I can't even remember the number of times that I've read people discuss or sell "mint" cameras and then list a number of serious problems. If it doesn't work or has problems, it's not mint.

 

[David Brown]

I'd have guessed the most mis-used words on the 'net were ...

Sorry. It's "your", as in "Your the one!" :rolleyes:

 

[Dan Fromm]

Lense, anyone? Singular of lenses.

 

[Chazzy]

Lense, anyone? Singular of lenses.

That one drives me absolutely crazy. Lens only has four letters. How can any photographer screw up that simple, four-letter word?

 

[KD5NRH]

How about the use of an apostrophe as a warning that an "s" is about to appear at the end of a word?
juan

IMO, if it's going to be u'sed that way, it 'should just be u'sed every time an 's i's coming up.

I can understand mixing up "its" and "it's" in posessives, but using the apostrophe to pluralize should be severely punished.

Don't get me started on "servicing" and "utilizing," either.

 

[Tom Hoskinson]

Lense, another annoyance to me.

Yes those really annoy me too. Along with accept and except. e.g. "payment by Paypal excepted".



Steve.

Lense can often be found on eBay (and Apug).

 

[Dan Fromm]

Tom, many people, including native speakers, haven't learned English very well. And many of those who speak it fluently have trouble with spelling. English orthography is, to be polite, difficult. My cohort was drilled until we learned to spell. I have the impression that our children and grandchildren weren't.

 

[Marco B]

As a non-native English speaker, I may add to this, that for many of us out here on the internet, it is all to easy to mix up words like accepted and excepted. As a non-native speaker, writing just doesn't come as a second nature, and the spoken language sometimes interferes while writing, causing minor mishaps between words that "sound" similar, like these two...

I often find myself re-reading an APUG post, and discovering just these kind of spelling errors. Unfortunately, APUG doesn't allow you to edit any post after a day or so, so we're doomed for ever...

Fortunately, with the English language packs installed in Firefox, and spell checking running along side (he, site and side, isn't that in the top 10 too? (to and too )) things are a little better.

 

[Dan Fromm]

Marco, one of the joys of English is its many homonyms. Side, sighed. Road, rode. Red, read. The first two pairs are noun, verb; the third is adjective, verb. But side is also an adjective. Spell catchers don't always catch a misused homonym. More traps for people who weren't drilled on spelling when very young. So many rules, with so many exceptions.

Speaking English correctly is possible, writing it correctly isn't.

 

[Steve Smith]

I have found that non-native English speakers write better English than some native speakers. Probably because they have to put a bit of thought into it.

Dan, surely you mean 'writing it correctly is not' !!!



Steve.

 

[Steve Smith]

Speaking of writing correctly, how did I manage to post the last message three times?

 

[Dan Fromm]

Steve, as far as I know some contractions are permitted. "Ain't" ain't, except among huntin', shootin', fishin' kinds of people.