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12-30-2006, 11:27 AM   #1
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kenko and tamron tele converters

i had read these two were the same.. having inspected a couple.. one tamron 1.4 and one kenko 1.5 they quite clearly are one and the same product..

my son had the tamron i liked it but couldnt locate one so bought the kenko.. they both work very nicely and are one and the same..

names apart they are indentcal in every respect..



trog

12-30-2006, 12:39 PM   #2
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To me, they wash out colour and soften the images too much.

They work alright when I put on 77 ltd. The colour is still rich but not the sharpness.

That is why I am getting pentax A rear 1.4 X and 2X teleconverter and 2X L teleconverter to give it a go. Since L converter costing about 550 US dollars and A rear converter about 380 US dollars, hopefully they would be better than the aforementioned teleconverters.
12-30-2006, 01:34 PM   #3
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well they work a million times better then i expected them to.. he he

i expected a noticable image quality degrade.. having tried them on several lenses from 50mm primes to 70 to 300 zooms i really cant see any meaningfull difference in the image quality useing them..

i am not seeing what i expected to see.. and i have looked very close to find faults with them.. he he

my son bought his cheap off ebay.. for the price it was worth a try.. he didnt expect much from it.. i paid full price for mine hoping t was as good as the one he got.. it is..

from an image quality point of view i really cant fault the things.. he he

i admit there must be some image quality degade.. nothing in this world comes free.. but all the fullsize pixel peeping i have done hasnt really shown it up..

i have looked clsoely for center area sharpness and general colour loss.. i havnt peeped right in the corners of images looking for increased drop off and such...

trog

ps.. u must need converters pretty badly to think in terms if spending nearly a 1000 dollars.. i had to think twice about spending 70 for mine.. he he
12-30-2006, 04:49 PM   #4
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Hi trog. I am just having obsessive and compulsive traits that I would not stop anything I do until exhaustion...

BTW I bought my tamron 1.4 for 150 US dollars on ebay used. Yes, I am not really using my cerebral cortex here. The ebayer probably thought I was a fat cow to milk more money out of me.

I guess tamron works well with certain primes as it worked reasonable on my 77 ltd. Sharpness and colour are all reasonable and I had to double check everything I see on pixel peeping is true.

On my bigma and A*300 f2.8, tamron wrecks every single image.

Since it is a bargain, I would not complain much about it.

I am desperate to find a good teleconverter just only to see if I could get the superb image once A*300 f2.8 became 600 f5.6 with the pentax 2X L adaptor.

That means no weight issue of owning a Fa600 f4 which is only sharp after 5.6 aperture anyway and it is impossible to find Fa600 f4 anyway. Costing a lot with special order on bhphoto.

I have a kenko 1.4X for canon body with canon 1.4 X and 2 X. I hated them all sitting on my shelf. I cannot even sell them on ebay bceause it is just not worth it losing lots of money. I have a hatred to adaptor.

But bear in mind, I have never seen adaptors just designed for A* alone. So I am very keen to find out ...

Cheers

12-30-2006, 11:20 PM   #5
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the converters seem to have some gearing affect built in.. the little screwdriver is geared down not straight thru.. on a super zoom which is low geared anyways they work but kinda wreck the autofocus speed.. possibly even the autofocus accuracy.. its pretty much impossible to turn the manual focus ring on my 18 to 200 with one on.. on my sigma 70 to 300 the image quality is okay but the lens losed its useability due to the gearing affect the converter has.. its very noticable on a lens that has to move a long way..

quite why they are geared down i can only guess.. a slower moving lens will focus better with one on.. only a guess thow..

they work best on a nice fast prime i think that dosnt have to move its elements far. not as i have any autofocus long ones.. he he

trog
12-31-2006, 04:02 PM   #6
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just did couple of tripod tests to check the 1.4 or 1.5 factor..

whatever the real figure is both converters are exactly the same and produce identical images..

full frame image with converter on sigma 50mm at f2.8 1/8 second iso 200..



100% crop from centre of image..



trog
12-31-2006, 04:12 PM   #7
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Hey Trog. Sigma 50 f2.8 macro is a FINE lens. That was the lens that changed my perception of sigma new lens line up.

The adaptor (as I had told you) worked well with my 77 Ltd as well.

So the adaptor does not work well consistently with some other quality lenses.

Joele had the lens in the past as well and I used to feel depressed because of how aweful my canon 50 f1.4 images compared to sigma 50 f2.8 macro

My own canon 50 f2.8 macro or 100 f2.8 macro were not any better than sigma 50 f2.8 either. Sigma 50 f2.8 is considerably smaller than canon ones and its colour is actually richer.

Though, I had to mention this: pentax lenses are considerably smaller, more compact and light weighted compared to the chunky sigma lens with respective unique colour rendition and sharpness.
12-31-2006, 04:29 PM   #8
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yes sigma lenses arnt small and the 50mm macro moves a long and slow way getting its focus but optically i think its flawless.. i would like the 105mm sigma but money is too damned easy to spend.. he he

trog

01-10-2007, 04:07 PM   #9
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QuoteOriginally posted by trog100 Quote
i admit there must be some image quality degade.. nothing in this world comes free.. but all the fullsize pixel peeping i have done hasnt really shown it up..

i have looked clsoely for center area sharpness and general colour loss.. i havnt peeped right in the corners of images looking for increased drop off and such.


Yesterday, I took this picture of a pelican splashing down (as well as most of the others in this gallery), using the Pentax 75-300 + the Tamron 1.4x converter. I'm new to the lens game and not as discerning as you guys, but I have to say I was pretty pleased with these shots.

I know I spent well under $100 for the Tamron converter, just before Christmas. If I were going to spend a lot more, I'd just buy a new and better lens.

Will
01-10-2007, 10:55 PM   #10
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QuoteOriginally posted by WMBP Quote
Yesterday, I took this picture of a pelican splashing down (as well as most of the others in this gallery), using the Pentax 75-300 + the Tamron 1.4x converter. I'm new to the lens game and not as discerning as you guys, but I have to say I was pretty pleased with these shots.

Will
That is q very impressive photo!

By the way, does the Tamron converter report the correct focal lengrh and f/#
to the camera (as seen in the EXIF data), or does it pass the lens info
straight through? Getting the right focal length is probably important for
shake reduction to work well.
01-10-2007, 11:06 PM   #11
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QuoteOriginally posted by TomG Quote
That is q very impressive photo!

By the way, does the Tamron converter report the correct focal lengrh and f/# to the camera (as seen in the EXIF data), or does it pass the lens info
straight through? Getting the right focal length is probably important for
shake reduction to work well.
I'm embarrassed to say that I'm not sure I know the answers to your questions. I can say that the converter does not change the EXIF data about the focal length. In other words, I started shooting yesterday with just the Pentax 75-300 and of course most of the time I was at 300. Then I pulled the 1.4x converter out and added it to the camera. ALL of the pictures show that the focal length = 300mm. I have got to come up with some sort of a system to keep track of when I make these changes to the equipment that don't get recorded in the EXIF data.

I am not sure about this, but I suspect that this failure to report the focal length as, say, 420, is not a mistake. I would love to have this confirmed by somebody who actually knows, but my suspicion is that the converter does not extend the focal length - it magnifies the image that's received. But I could be wrong about that. One of the 1000 things I have to learn more about.

Shake reduction clearly works fine. I used the monopod as much as possible but a lot of the shots in that gallery were taken hand held and by and large the results were satisfactory or better.

Will
01-11-2007, 05:56 AM   #12
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I recently acquired a Promaster Spectrum 7, 1.7X automatic Teleconverter from a local used camera store in Louisville, KY. So far I am very pleased with the results from this Teleconverter when used with my Pentas iDS and a Tamrom 18 - 200 XR Macro Zoom Lens. I am including a picture I took yesterday with this combination of settings, (automatic), ISO 800, 1/500 second speed, zoom 108mm, 1.5 digital & 1.7 teleconverter equal total zoom of approximately 275mm.

Last edited by wipearl; 03-02-2007 at 11:02 PM.
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