T-Mount?

Tom Lusk · 10-07-2007, 06:54 PM

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I've just purchased a 600mm T-mount lens - now I need an adapter for my K100.

So... are all Pentax T-mount adapters created equal?

Will this work?:

T2 T-2 T-MOUNT adapter for Pentax K Film Digital SLRs - (eBay item 190158751485 end time Oct-08-07 18:01:56 PDT)

Big Dawg · 10-07-2007, 07:22 PM

I have one too and it will not fit a M42 screw mount...Different thread size. Got to have a T-mount lens for it to work. Go here for an explanation.
T-mount - Wikipedia, the free encyclopedia

The problem with the T-mounts is they will move the lens further away from the film plane or the sensor and not give you infinity focus.

Dawg

hinckc · 10-07-2007, 07:35 PM

Hi Tom,

I haven't used the one you linked to, but it makes me nervous, just because they only show pics of one side of it. What's the matter with the other side? I'm just very hesitant to order on-line from a seller who provides so little info about a product.

I have 2 different T-mount adapter rings, one Bower, and one no-name one (it just says "For Pentax" on it). One I got from my local camera shop, and one came with my phoenix 500mm mirror lens. I don't notice any difference between the two. They both seem to perform identically.

I can't wait to see the results of you having (even more) reach, and look forward to more fantastic avian and amphibian pictures!

-Chris

Peter Zack · 10-07-2007, 07:41 PM

Big Dawg, I'm confused with your answer. I have a couple of these mounts and use them for my Bellows unit. The M42 bellows will screw directly to the T mount. I don't own the type of lens Tom refers to but if it is designed to take a T mount why wouldn't this work and give infinity focus. I'd assume the lens mount is M42 and is recessed to get the rear element seated at the correct distance from the sensor. Much like the newer adaptall Tamron mounts.

Tom, I have one that was an original Tamron version and the other is similar to the one you linked to. The generic one is not machined as well but works fine. I just happened across another (the Tamron version) for almost nothing and it does fit on the camera smoother, like any good Pentax lens.

dantuyhoa · 10-07-2007, 08:50 PM

Originally posted by Tom Lusk

I've just purchased a 600mm T-mount lens - now I need an adapter for my K100.

So... are all Pentax T-mount adapters created equal?

Will this work?:

T2 T-2 T-MOUNT adapter for Pentax K Film Digital SLRs - (eBay item 190158751485 end time Oct-08-07 18:01:56 PDT)

You got your hand on a Solid Cat ???

Tom Lusk · 10-08-2007, 06:08 AM

Thanks for the input, everyone.

I'll give it a try.

And, yep! it is the Solid Cat! I was watching two of them.

The 450 went for $1295.00, but I got the mint 600 for just $395.00.

Now to see if this lens is as good as its reputation...

JCSullivan · 10-08-2007, 06:36 AM

So far as I know, Lenses that require T-mounts have a different thread. It has I think a different pitch on the thread and so far as I know will NOT screw right into the M42.

I could be wrong but I'm almost 100% sure.

little laker · 10-08-2007, 08:43 AM

Tom, there are 2 things that I've noticed about my only T-Mount lens which I'm not overly fond of

The important thing.
A little paint came off it once, and I'm a little worried that it'll happen again, ending up in the camera.
This can be remedied with a little paint remover or a sand blaster, I just haven't done it yet.

The second thing, is at least with my setup the focus indicator doesn't work

I don't know if I just have to change some setting, but it does work with my M42 lens.

Other than that I don't think that you can go wrong with a T-mount lens.

unkbar · 10-08-2007, 10:36 AM

I use the 800mm Solid CAT with my K10D.

The Pentax M42 screwmount and the T-mount are different. The M42 is 42mmX1mm and the T-mount is 42mmX0.75mm. That means one rotation of the thread moves the lens either .75 or 1 mm. They are NOT interchangable, you WILL ruin your lens if you try forcing it into the wrong adapter.

I was heartbroken to find that my 800mm Solid CAT runs into the flash housing on my K10D before it gets tight in the T-mount. Does your K100 have that problem, too? If I screw it about halfway into the T-mount, it seemed to focus to infinity okay, and it seemed pretty secure, so I'm planning to make a plastic disk to use as a spacer so I don't go scuffing the front of the flash housing everytime I use the lens. I'm not about to give up all that Perkin-Elmer goodness because of a mere mechanical mishap.

Clem Nichols · 10-08-2007, 12:41 PM

Originally posted by Tom Lusk

Thanks for the input, everyone.

I'll give it a try.

And, yep! it is the Solid Cat! I was watching two of them.

The 450 went for $1295.00, but I got the mint 600 for just $395.00.

Now to see if this lens is as good as its reputation...

OK, guys. Somebody do me a favor, and tell me what is a Solid CAT lens.

Thanks
CN

unkbar · 10-08-2007, 12:57 PM

Its a "Solid Catadioptic" lens. Catadioptic means it contains both lenses and mirrors. "Solid" means that there are no air spaces between those lenses and mirrors. This means it is small and rugged.

They were made by Perkin-Elmer in the Seventies, and were sold under the Vivitar "Series One" brand. Perkin-Elmer is a major government contractor and the builder of the infamous Hubble space telescope mirror. Some people say the Vivitar Solid CATs were made to a NASA or military design. I don't know, but it's a darn good lens.

Not Registered · 10-08-2007, 12:59 PM

Originally posted by Clem Nichols

OK, guys. Somebody do me a favor, and tell me what is a Solid CAT lens.

Thanks
CN

Somebody can correct me if I am wrong. But if my memory does not trick me, they were extremely compact, long focal length mirror lenses made by Vivitar in the Jackson's Five years.

MPrince · 10-08-2007, 02:22 PM

Originally posted by little laker

The second thing, is at least with my setup the focus indicator doesn't work

I don't know if I just have to change some setting, but it does work with my M42 lens.

Other than that I don't think

In the Custom Setting menu, make sure that FI with S lens used is set to available. It probably is, since FI works with your M42 lens. But it's the only thing I can think of at the moment. I don't have any M42 lenses, but I do have a t-mount lens, and FI does work.

Clem Nichols · 10-08-2007, 04:38 PM

Originally posted by MPrince

In the Custom Setting menu, make sure that FI with S lens used is set to available. It probably is, since FI works with your M42 lens. But it's the only thing I can think of at the moment. I don't have any M42 lenses, but I do have a t-mount lens, and FI does work.

I've been through the custom setting menu on my K10D three times now, and can't seem to find anything about FI setting. I've just purchased an old tele-takumar 400/5.6, but haven't yet received an M42 to K mount adapter which I ordered from B&H. I'm certainly hoping that the FI works with this lens, but if it doesn't, then what are my options? Thanks.

CN

little laker · 10-08-2007, 06:43 PM

Originally posted by MPrince

In the Custom Setting menu, make sure that FI with S lens used is set to available. It probably is, since FI works with your M42 lens. But it's the only thing I can think of at the moment. I don't have any M42 lenses, but I do have a t-mount lens, and FI does work.

Thanks MPrince

I had already tried that, and it doesn't work with mine

I wonder if there's a difference with adapter's. If I changed to another brand it might just work

Originally posted by Clem Nichols

I've been through the custom setting menu on my K10D three times now, and can't seem to find anything about FI setting. I've just purchased an old tele-takumar 400/5.6, but haven't yet received an M42 to K mount adapter which I ordered from B&H. I'm certainly hoping that the FI works with this lens, but if it doesn't, then what are my options? Thanks.

CN

On the K100D it's Menu
C
FI with S lens used should be set to 2

10-07-2007, 06:54 PM	#1
Tom Lusk Veteran Member Join Date: Sep 2006 Photos: Gallery Posts: 973	T-Mount? Staff note: This post may contain affiliate links, which means Pentax Forums may earn a small commission if a visitor clicks through and makes a purchase. If you would like to support the forum directly, you may also make a donation here. I've just purchased a 600mm T-mount lens - now I need an adapter for my K100. So... are all Pentax T-mount adapters created equal? Will this work?: T2 T-2 T-MOUNT adapter for Pentax K Film Digital SLRs - (eBay item 190158751485 end time Oct-08-07 18:01:56 PDT)

10-07-2007, 07:22 PM	#2
Big Dawg Senior Member Join Date: Oct 2007 Location: Thach, Alabama Photos: Gallery \| Albums Posts: 169	I have one too and it will not fit a M42 screw mount...Different thread size. Got to have a T-mount lens for it to work. Go here for an explanation. T-mount - Wikipedia, the free encyclopedia The problem with the T-mounts is they will move the lens further away from the film plane or the sensor and not give you infinity focus. Dawg Last edited by Big Dawg; 10-07-2007 at 07:23 PM. Reason: Addition

10-08-2007, 06:08 AM	#6
Tom Lusk Veteran Member Join Date: Sep 2006 Photos: Gallery Posts: 973 Original Poster	Thanks! Thanks for the input, everyone. I'll give it a try. And, yep! it is the Solid Cat! I was watching two of them. The 450 went for $1295.00, but I got the mint 600 for just $395.00. Now to see if this lens is as good as its reputation...

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10-07-2007, 07:35 PM	#3
hinckc Senior Member Join Date: Apr 2007 Location: New Jersey, USA Photos: Gallery Posts: 298	Hi Tom, I haven't used the one you linked to, but it makes me nervous, just because they only show pics of one side of it. What's the matter with the other side? I'm just very hesitant to order on-line from a seller who provides so little info about a product. I have 2 different T-mount adapter rings, one Bower, and one no-name one (it just says "For Pentax" on it). One I got from my local camera shop, and one came with my phoenix 500mm mirror lens. I don't notice any difference between the two. They both seem to perform identically. I can't wait to see the results of you having (even more) reach, and look forward to more fantastic avian and amphibian pictures! -Chris

10-07-2007, 07:41 PM	#4
Peter Zack Pentaxian Moderator Emeritus Join Date: May 2007 Location: Edmonton Alberta, Canada Photos: Gallery \| Albums Posts: 10,643	Big Dawg, I'm confused with your answer. I have a couple of these mounts and use them for my Bellows unit. The M42 bellows will screw directly to the T mount. I don't own the type of lens Tom refers to but if it is designed to take a T mount why wouldn't this work and give infinity focus. I'd assume the lens mount is M42 and is recessed to get the rear element seated at the correct distance from the sensor. Much like the newer adaptall Tamron mounts. Tom, I have one that was an original Tamron version and the other is similar to the one you linked to. The generic one is not machined as well but works fine. I just happened across another (the Tamron version) for almost nothing and it does fit on the camera smoother, like any good Pentax lens.

10-07-2007, 08:50 PM	#5
dantuyhoa Veteran Member Join Date: May 2007 Location: California Photos: Gallery Posts: 1,245	Originally posted by Tom Lusk I've just purchased a 600mm T-mount lens - now I need an adapter for my K100. So... are all Pentax T-mount adapters created equal? Will this work?: T2 T-2 T-MOUNT adapter for Pentax K Film Digital SLRs - (eBay item 190158751485 end time Oct-08-07 18:01:56 PDT) You got your hand on a Solid Cat ???

10-08-2007, 06:36 AM	#7
JCSullivan Veteran Member Join Date: Sep 2006 Location: Windsor, Canada Posts: 3,056	So far as I know, Lenses that require T-mounts have a different thread. It has I think a different pitch on the thread and so far as I know will NOT screw right into the M42. I could be wrong but I'm almost 100% sure.

10-08-2007, 08:43 AM	#8
little laker Veteran Member Join Date: Sep 2006 Photos: Gallery Posts: 5,697	Tom, there are 2 things that I've noticed about my only T-Mount lens which I'm not overly fond of The important thing. A little paint came off it once, and I'm a little worried that it'll happen again, ending up in the camera. This can be remedied with a little paint remover or a sand blaster, I just haven't done it yet. The second thing, is at least with my setup the focus indicator doesn't work I don't know if I just have to change some setting, but it does work with my M42 lens. Other than that I don't think that you can go wrong with a T-mount lens.

10-08-2007, 10:36 AM	#9
unkbar New Member Join Date: Jul 2007 Posts: 15	I use the 800mm Solid CAT with my K10D. The Pentax M42 screwmount and the T-mount are different. The M42 is 42mmX1mm and the T-mount is 42mmX0.75mm. That means one rotation of the thread moves the lens either .75 or 1 mm. They are NOT interchangable, you WILL ruin your lens if you try forcing it into the wrong adapter. I was heartbroken to find that my 800mm Solid CAT runs into the flash housing on my K10D before it gets tight in the T-mount. Does your K100 have that problem, too? If I screw it about halfway into the T-mount, it seemed to focus to infinity okay, and it seemed pretty secure, so I'm planning to make a plastic disk to use as a spacer so I don't go scuffing the front of the flash housing everytime I use the lens. I'm not about to give up all that Perkin-Elmer goodness because of a mere mechanical mishap.

10-08-2007, 12:41 PM	#10
Clem Nichols Veteran Member Join Date: Mar 2007 Location: Munfordville, Ky. Photos: Gallery Posts: 370	Originally posted by Tom Lusk Thanks for the input, everyone. I'll give it a try. And, yep! it is the Solid Cat! I was watching two of them. The 450 went for $1295.00, but I got the mint 600 for just $395.00. Now to see if this lens is as good as its reputation... OK, guys. Somebody do me a favor, and tell me what is a Solid CAT lens. Thanks CN

10-08-2007, 12:57 PM	#11
unkbar New Member Join Date: Jul 2007 Posts: 15	Its a "Solid Catadioptic" lens. Catadioptic means it contains both lenses and mirrors. "Solid" means that there are no air spaces between those lenses and mirrors. This means it is small and rugged. They were made by Perkin-Elmer in the Seventies, and were sold under the Vivitar "Series One" brand. Perkin-Elmer is a major government contractor and the builder of the infamous Hubble space telescope mirror. Some people say the Vivitar Solid CATs were made to a NASA or military design. I don't know, but it's a darn good lens.

10-08-2007, 12:59 PM	#12
Not Registered Guest	Originally posted by Clem Nichols OK, guys. Somebody do me a favor, and tell me what is a Solid CAT lens. Thanks CN Somebody can correct me if I am wrong. But if my memory does not trick me, they were extremely compact, long focal length mirror lenses made by Vivitar in the Jackson's Five years.

10-08-2007, 02:22 PM	#13
MPrince Veteran Member Join Date: Sep 2006 Location: WV Posts: 1,495	Originally posted by little laker The second thing, is at least with my setup the focus indicator doesn't work I don't know if I just have to change some setting, but it does work with my M42 lens. Other than that I don't think In the Custom Setting menu, make sure that FI with S lens used is set to available. It probably is, since FI works with your M42 lens. But it's the only thing I can think of at the moment. I don't have any M42 lenses, but I do have a t-mount lens, and FI does work.

10-08-2007, 04:38 PM	#14
Clem Nichols Veteran Member Join Date: Mar 2007 Location: Munfordville, Ky. Photos: Gallery Posts: 370	Originally posted by MPrince In the Custom Setting menu, make sure that FI with S lens used is set to available. It probably is, since FI works with your M42 lens. But it's the only thing I can think of at the moment. I don't have any M42 lenses, but I do have a t-mount lens, and FI does work. I've been through the custom setting menu on my K10D three times now, and can't seem to find anything about FI setting. I've just purchased an old tele-takumar 400/5.6, but haven't yet received an M42 to K mount adapter which I ordered from B&H. I'm certainly hoping that the FI works with this lens, but if it doesn't, then what are my options? Thanks. CN

10-08-2007, 06:43 PM	#15
little laker Veteran Member Join Date: Sep 2006 Photos: Gallery Posts: 5,697	Originally posted by MPrince In the Custom Setting menu, make sure that FI with S lens used is set to available. It probably is, since FI works with your M42 lens. But it's the only thing I can think of at the moment. I don't have any M42 lenses, but I do have a t-mount lens, and FI does work. Thanks MPrince I had already tried that, and it doesn't work with mine I wonder if there's a difference with adapter's. If I changed to another brand it might just work Originally posted by Clem Nichols I've been through the custom setting menu on my K10D three times now, and can't seem to find anything about FI setting. I've just purchased an old tele-takumar 400/5.6, but haven't yet received an M42 to K mount adapter which I ordered from B&H. I'm certainly hoping that the FI works with this lens, but if it doesn't, then what are my options? Thanks. CN On the K100D it's Menu C FI with S lens used should be set to 2