Forum: Pentax SLR Lens Discussion
09-14-2008, 05:25 AM
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Hello !
" Varifocal " is originaly the trade mark of first zoom produced in 1953 by Pierre Angenieux famous French manufacturer of hight quality optics.
Patent abstract :
Title:Varifocal objective and process for controlling it. Document Type and Number:European Patent EP0289392 Kind Code:A1
"Varifocal" is now à generic word for zoom optics
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Forum: Pentax SLR Lens Discussion
09-05-2008, 11:49 PM
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Hi all !
Just received my new Bigma and proceeded to some tests with K20D + Tamron 1.4 AF TC :
1/ At 500 mm / 700 mm with TC 1.4 x / 1050 mm considering sensor factor 1.5 x , Wahou !!!:
2/ 100 % crop :
Shoot with tripod from my office window at 10 m / 12-13 yards, EXIF included.
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Forum: Pentax SLR Lens Discussion
09-03-2008, 12:05 AM
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Thanks for yr opinions. But I'm mainly interested whith the relation between sensor definition according to lens definition .
For exemple, few month ago I used Tamron SP 300mm f/5.6 monted on K10 for pretty good results , same lens, on K20, produced very poor resolution and IQ.
This problem caused by sensor/lens definition, photosites size and diffraction characteristics, occurs quitte often when sensor definition is highter than lens one and become critical with 5 µm photosites sensor.
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Forum: Pentax SLR Lens Discussion
08-30-2008, 11:30 PM
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Hi all !
I just ordered a new Bigma in complement / replacement of my actual 50-135 DA*, Sig. 135-400 (to be sold...) and Sig. 500 f/4.5 .
What is the best Body/Lens couple to use as well for better IQ , sensibility and S/N ratio :
- K10D 10 Mp Cds + Bigma or K20D 14,6 Mp Cmos + Bigma ?
For exemple , I get much better results with 50-135 DA* mounted on K20D than K10D .
K10D seems a little bit better whith Sig. 135-400 and no significative diference between K10D and K20D coupled with Sig. 500 f/4.5 .
Thanks for advices / experiences
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Forum: Pentax SLR Lens Discussion
08-29-2008, 12:45 PM
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Hi !
Plastic bags + 16-50 DA* + 50-135 DA*
Don't forget these : Penn Reels
Good shoots !
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Forum: Welcomes and Introductions
08-25-2008, 03:08 AM
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Y are certainly speaking of Alpine cars from Jean Rédélé ...
Welcome to the "Alpine lovers Club" !!!
I still own a Berlinette 1600S 1972 (short gearbox) in quite good original condition .
Unfortunatly Alpine was completly integrated to Renault from 20 years, and they are producing special series of "normal" consumers cars.
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Forum: Pentax SLR Lens Discussion
08-24-2008, 11:55 AM
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nobody knows this Sigma lens ?
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Forum: Welcomes and Introductions
08-24-2008, 11:51 AM
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Many thanks for your welcome "on board" Pentax Forum !
Et aussi rassuré par la présence de francophones ...
A bientot .
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Forum: Pentax SLR Lens Discussion
08-24-2008, 05:55 AM
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Hi all !
I have the oportunity to get a K. mount Sigma AF 300 mmf/4 APO (at relativly decent price for Europe... )
Looking for advice, test and pictures from users of this not very known lens .
Many thanks
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Forum: Pentax SLR Lens Discussion
08-23-2008, 06:25 AM
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An other shoot taken during last full moon with Sigma 135-400 +TC Tamron 1.4 x :
Other one a few month ago, same lens, but a composit of about 30 shoots .
Restitution with IRIS V.5.51 :
Robert Capa says : " If your pictures are not good, you are not close enough ..."
... With a good software as IRIS , distance ( 384 400 km Earth/Moon ) is not a real problem , everything become close enough !
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Forum: Welcomes and Introductions
08-22-2008, 01:42 PM
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Very pleased to read this very interesting forum from months , why not become active ?
Be indulgent with my poor syntax ... I will try to improve !
Pentaxian from one year, I also use argentic medium and large format (Hasselblad and Linhof)
Regards and good shoots
Edgar
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