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05-20-2008, 02:20 PM   #91
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Sigma 135-400

Thought I might post a sample for you taken with this lens. Actually this was taken with a Tamron 1.4TC attachd as well. This may give you some idea of its quality.
I can certainly recommend this lens as a good budget lens.

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05-20-2008, 03:01 PM   #92
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QuoteOriginally posted by David07 Quote
This is a very interesting thread !

I also enjoy birding and I recently got a Tamron adaptall SP 300mm f/2.8 (60B) (I already had a PKA adapter). I really like this lens. It is very sharp and it pairs well with my TCs.

With my Pentax AF 1.7X, it is still very sharp, but this TC is adding a lot of purple fringing and CA. Maybe the lens itself has some CA, but without TC, it seems absent or really minor. I think I'm not so good in post-processing, so I have trouble removing CA even with the tools in Silkypix...

With my Tamron adaptall 2X (regular model 01F), it seems less sharp than with the Pentax 1.7X, but it is still ok. It gives a 600mm f/5.6, which can sometimes be very useful ! Again, PF and CA will be there, but it doesn't seem as bad as with the 1.7X.

I tried yesterday with a Tamron adaptall 1.4X and I really liked it. A little bit of CA, but MUCH better than with the 1.7X and it is not an issue. I've got some nice pics with the lens set at f/4 (should be an effective f/5.6 because of the TC) with good blurred background.

I still have to try with my Kenko 1.5X...

David
I have a question for you. What is the diameter of the elements in the Kenko 1.5x, and what is the diameter of the elements in the 1.7x AF Pentax?
05-20-2008, 06:20 PM   #93
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QuoteOriginally posted by konraDarnok Quote
I have a question for you. What is the diameter of the elements in the Kenko 1.5x, and what is the diameter of the elements in the 1.7x AF Pentax?
Hello,

my Kenko 1.5X is this version: Pz-AF Teleplus SHQ. The diameter of the elements on the lens side is around 22mm and around 27 mm on the camera side.

For the pentax 1.7X: around 20mm on lens side and 25 mm on the camera side.

I'm not sure of why you asked this question, but I hope this help !

David
05-20-2008, 06:20 PM   #94
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I've been looking at the Tamron sp 300 and almost went that way a couple times. I think the f2.8 would be very helpful plus with the tc it is still a fast lens.
I think the faster the better for me right now because I am still trying to get the technique of handholding down so the quicker I can get that shutter to go the better

Anyway, I'm happy with this purchase though but I have yet to aquire a TC. Its hard to find things in Pentax mount.

05-20-2008, 06:56 PM   #95
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QuoteOriginally posted by David07 Quote
Hello,

my Kenko 1.5X is this version: Pz-AF Teleplus SHQ. The diameter of the elements on the lens side is around 22mm and around 27 mm on the camera side.

For the pentax 1.7X: around 20mm on lens side and 25 mm on the camera side.

I'm not sure of why you asked this question, but I hope this help !

David
I was just curious if it might be possible to switch the 2 lens groups, as I'm betting they're just a single cemented unit in either case, held in with a threaded washer. . .tho maybe not. . and switch them out -- to get a 1.5x modded Pentax AF converter -- if for no reason than the Kenko group would be a half f-stop faster. My brain ponders such questions.

That, and I've been proceeding in line with this thread. I have an AF 1.7x and a 300mm 2.8 adaptall coming in the mail. And I haven't even been following the thread.

But for my purposes it would be useful to have a less aggressive magnification on the TC. But I shall see. I haven't got anything yet.

It also occurred to me that with the AF 1.7x you might be able to mount old FD glass (with a suitably constructed custom adapter) -- as the registration flange distance incompatibility should counteracted by the moving teleconverter, no?

Tho, even obsolete FD 300mm 2.8 glass is still fairly expensive on eBay, however, the FD 200mm 2.8 glass is affordable. I may yet try to construct such a Frankenstein from a flanged m42-K adapter and an FD body flange from an old teleconverter.

Why? well, FD glass is fairly useless and of high quality. An avenue to turn the old telephotos into autofocus Pentax glass sounds attractive.

Last edited by konraDarnok; 05-20-2008 at 07:11 PM.
05-20-2008, 09:00 PM   #96
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QuoteOriginally posted by konraDarnok Quote
I was just curious if it might be possible to switch the 2 lens groups, as I'm betting they're just a single cemented unit in either case, held in with a threaded washer. . .tho maybe not. . and switch them out -- to get a 1.5x modded Pentax AF converter -- if for no reason than the Kenko group would be a half f-stop faster. My brain ponders such questions.

That, and I've been proceeding in line with this thread. I have an AF 1.7x and a 300mm 2.8 adaptall coming in the mail. And I haven't even been following the thread.

But for my purposes it would be useful to have a less aggressive magnification on the TC. But I shall see. I haven't got anything yet.

It also occurred to me that with the AF 1.7x you might be able to mount old FD glass (with a suitably constructed custom adapter) -- as the registration flange distance incompatibility should counteracted by the moving teleconverter, no?

Tho, even obsolete FD 300mm 2.8 glass is still fairly expensive on eBay, however, the FD 200mm 2.8 glass is affordable. I may yet try to construct such a Frankenstein from a flanged m42-K adapter and an FD body flange from an old teleconverter.

Why? well, FD glass is fairly useless and of high quality. An avenue to turn the old telephotos into autofocus Pentax glass sounds attractive.
The Pentax 1.7 is not the best converter to hack. It is fitted with autofocusing elements. I know it is considerably thicker than my SMC-P A 1.4X S converter. Half again thicker at least.
05-20-2008, 09:17 PM   #97
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sigma 100-300dl

For $60 this lens will do me.
05-20-2008, 09:21 PM   #98
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oops no pic

Attachment 12589

Attachment 12590
Sigma 100-300mm DL good value for $60


Last edited by trumpyman; 06-09-2008 at 10:01 PM.
05-20-2008, 09:50 PM   #99
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Maybe I should have saved the money, Nice trumpyman.
05-21-2008, 11:16 AM   #100
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Very nice shots trumpyman.
05-23-2008, 04:29 PM   #101
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This is about the best I could do with a Vivitar S1 v3 at 210mm with the Pentax 1.7X AF TC. Shot was hand held. Some folks on the same tour were getting better pictures using a P&S and a spotting scope. Granted they also had to use a tripod.

Cropped image after mild PP from a RAW shot.


Not-Cropped (bird was much closer). Fast shot was very thankful for auto focus and Av.
05-23-2008, 06:56 PM   #102
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QuoteOriginally posted by tybeck Quote
This is about the best I could do with a Vivitar S1 v3 at 210mm with the Pentax 1.7X AF TC. Shot was hand held. Some folks on the same tour were getting better pictures using a P&S and a spotting scope. Granted they also had to use a tripod.
A guy I shoot with sometimes brings his digiscope rig (spotting scope and point and shoot) he made the adapter and it looked pretty easy to do. The quality is really good if it is bright out, although it is a zeiss scope and quite pricey, he likes the video feature. He puts the little camera strap around the eyepiece because when the battery dies the lens retracts and the camera will fall off.

Here's one with the 1.7x afa and the da300mm
05-23-2008, 07:08 PM   #103
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Nice shot borno.
Itching to get out next week.

There was an A* 600mm that went for $2100 on ebay today. Man, I would have liked to of nabbed that one. I thought about it but it went pretty quick.
Didn't quite stay long enough for the LBA to kick in.
05-23-2008, 07:14 PM   #104
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QuoteOriginally posted by OrenMc Quote
Nice shot borno.
Itching to get out next week.

There was an A* 600mm that went for $2100 on ebay today. Man, I would have liked to of nabbed that one. I thought about it but it went pretty quick.
Didn't quite stay long enough for the LBA to kick in.
Thanks Oren,
I'm glad I didn't see that 600mm - I don't need that much temptation (plus I've got to keep a low profile for a while IYKWIM)
05-23-2008, 07:28 PM   #105
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Borno, That is a very nice heron....Very nice.
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