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Takumar-A 2x Tele-Converter Review RSS Feed

Takumar-A 2x Tele-Converter

Reviews Views Date of last review
12 44,109 Tue February 28, 2023
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Recommended By Average Price Average User Rating
58% of reviewers $35.00 5.91
Takumar-A 2x Tele-Converter
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Description:

This is a Pentax 2x teleconverter with KA mount lens information contacts. It doubles the focal length of the attached lens at the expense of loss of 2 stops of light.

Features of this teleconverter:

  • Manual Focus
  • Supports Tv or P exposure mode (in addition to M and Av), if the camera allows
  • The converter does not transmit focal length and MTF information from lens to camera
  • Can be used with most if not all lenses

Takumar-A 2X Tele-Converter
© www.pentaxforums.com, sharable with attribution
Image Format
Full-frame / 35mm film
Lens Mount
Pentax K
Light Loss
2 stops
Magnification
2x
Optics
4 elements, 3 groups
Mount Variant (Rear)
KA
Mount Variant (Front)
KA
Focusing
Manual
Coating
Weather Sealing
No
Case
Dedicated hard case
Diam x Length
60 x 25 mm (2.4 x 1 in.)
Weight
113 g (4 oz.)
Production Years
N/A
Notes
Engraved name: TAKUMAR-A 2X TELE-CONVERTER
User reviews
The converter does not retain the autofocus capability of the attached lens, focusing is manual only.
The converter retains all exposure modes supported by the attached lens.
The converter does not relay information about focal length, MTF, or lens name to the camera.
The converter can be used with most if not all K-mount lenses.
Features:
Automatic ApertureFull-Frame SupportDiscontinued
Price History:



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Sort Reviews by: Date | Author | Rating | Recommendation | Likes (Descending) Showing Reviews 1-12 of 12
New Member

Registered: July, 2013
Posts: 2

1 user found this helpful
Review Date: February 28, 2023 Not Recommended | Price: $75.00 | Rating: 3 

 
Pros: Well made
Cons: Mediocre optics

Optically, this extender was not very good. I used it occasionally to extend the reach of my 70-210 A with 35mm film, but the results were never satisfactory. As an extender, it's really of little practical use. Pulling the glass out transforms it into a brilliant 25mm extension tube that maintains auto aperture control. For that use, I'd rate it an 8.
   
Site Supporter

Registered: May, 2014
Location: Linz
Posts: 3,098
Review Date: February 4, 2023 Recommended | Price: $8.00 | Rating: 7 

 
Pros: A-contacts; reasonable sharp
Cons: low contrast

As this TC was offered at a bargain price I decided to try my luck despite the so-so reviews and I am mostly satisfied with its performance (on the original K-3).



+ reasonable sharp (IF you manage to nail focus; it will require some practice to manually focus on a moving target, as depth of field decreases significantly)
+ A-contacts allow to controll aperture via the camera
+ small + light

o two stops loss of light require a fast lens or a well lit subject to achieve focus manually, you will also need a lens, that out-resolves your camera or you can just crop instead

o my K-3 also requires half a stop more exposure compensation when used in combination with the 'slowish' Tokina SD 400mm F5.6 lens to not get an over-exposed image


- due to the missing lens coatings in the TC do the images lack contrast (maybe add some CAs too, but I have the impression that most of the CAs I see are just the increased flaws of the used lens in front of the TC)



The loss in contrast and amplified CAs necessitate post processing to achieve good image quality, but I don't mind as I usually don't use images sooc.

My main field of application for this TC will be hiking/mountaineering, as it gives me a light-weight and small-ish tele solution for occasional wildlife photograhy in combination with my Cosina MC 200mm F4 lens.

Comparison between usage of the TC and digital crop (both images are already PP)


Here is an example of the K-3 + Takumar-A 2x Tele-Converter + Cosina 200mm 1:4 MC combination @f8.


Colors and contrast needed extensive pp-work, but as a ligthweight hiking solution the pros outweigh the cons in my opinion.
   
Senior Member

Registered: May, 2012
Location: North Coast, NSW, Australia
Posts: 142
Review Date: January 19, 2021 Recommended | Price: $24.00 | Rating: 9 

 
Pros: Works on SDM and Sigma-HSM lenses
Cons: well, Manual-Focus, if that terrifies you

Yes, there is some loss of light, when using a TC.
There is a little loss of sharpness.
But, this is a very easy way to "carry-around" a lens with twice the focal length.
And, YES, this TC does work with the DA 17-70 SDM lens,
And, YES, this TC does work with Sigma 50-200 HSM lens.
Camera used was K-50.
Second photo taken with setup, as shown in photo-1, indoors, no flash, straight from Live-Action TV screen
   
Review Date: May 9, 2020 Recommended | Rating: 8 

 
Pros: Fun to work with, delivers good pictures, cheap
Cons: Reduces focusing space

This is a difficult Takumar product. It worked very well on my Super A. It is lot more difficult to use on a DSLR. The space for focusing half of what you get without the converter so it is making focusing difficult. Manually focusing on an APS-C is IMHO more difficult than on FF. So use the converter when you want to make pictures where you set the focus to infinity. I used it with my Pentax-A 50mm F1.4 set to infinity and it delivers a good and sharp picture. I had soft pictures too, but the subject were close by and that makes it more difficult focusing. I bought it through the Dutch Pentax club a short while after I bought my A 35-105 when this Takumar version was introduced. At that time there was not a Pentax version available and it was pleasantly priced. I recommend this converter because it works well if you are aware of its limitations and you can overcome them.
   
Site Supporter

Registered: December, 2012
Location: Spring Branch, Tx
Posts: 705
Review Date: October 14, 2018 Not Recommended | Price: $15.00 | Rating: 3 

 
Pros: Has A contacts
Cons: Has a lens in it

I bought this just for the mount, almost never used [soft is not the word for the images out of this converter] and perfect for a worn A lens mount. I decided to de-glass it today and it is now an auto extension tube. It only took 20 tries to get all the pins and the lens release spring stop [ this was the issue, all the data pins all went in easy ] in place....
   
Veteran Member

Registered: August, 2012
Posts: 678
Review Date: January 12, 2018 Not Recommended | Price: $15.00 | Rating: 6 

 
Pros: Extends lens reach
Cons: Excessive loss of sharpness

This little accessory takes me back to the very beginning of my 35mm SLR days when the first lens accessory I got was a Kmart Focal 2x teleconverter for the 50mm lens on my Minolta X-570. It extended the lens' reach but at the cost of a lot of sharpness. This one does exactly the same thing for my Pentax-KA 50mm f2.0 lens. This convinces me that this teleconverter was designed with for the modest purpose of providing a cheap way of doubling the focal range of a 50mm lens in somebody's starter kit.

I got this teleconverter for two reasons--it has a KA mount so it will allow more or less full functionality with the aforementioned 50mm lens and it was very inexpensive. That's a good thing since it really isn't adding any new functionality to my kit, which contains a number of better options in the 100mm range. Given its lackluster performance, I have no intention of trying to use it with any of my autofocus lenses, so it was really more of a nostalgia buy than anything else. The only reason I gave it a 6 out or 10 is that I knew what I was getting into and it thus met my realistically low expectations of its performance.

Note: This teleconverter came to me bundled with a Vivitar 50mm f2.0 lens so the $15 price shown above represents a portion of the $27 I paid for the two items together--$15 for the teleconverter and $12 for the lens--arbitrarily determined by the two items' relative value to me. The true cost of this teleconverter will be determined once I sell off the redundant lens and subtract that from the purchase price.
   
Loyal Site Supporter

Registered: October, 2016
Location: Euless Texas
Posts: 265
Review Date: December 12, 2016 Not Recommended | Price: $25.00 | Rating: 4 

 
Pros: Extra Reach
Cons: Turns sharp lenses soft

I bought this thinking that if I could turn my 55-300mm into a 600mm I could get more range at a small drop in sharpness. Wrong... This 2x teleconverter
softens shots to almost unusable. I found that it only takes decent shots in the best of light. I really wanted more detail in my moon shots and I found that no matter how much I tried to tweak the manual focus I could not get a decently sharp shot. This will go into a drawer and I will work on plan A again which is to get a lens with a native 400 or 500mm focal length. Only decent shot I took is below.


   
Senior Member

Registered: January, 2016
Posts: 242
Review Date: February 28, 2016 Recommended | Price: $35.00 | Rating: N/A 

 
Pros: Gives you 2x if needed
Cons: Very bad flaring under light

I ended up with 2 of these recently, one that I purchased on Ebay for about $35 and the other was attached to a telephoto that I also bought from Ebay. Main reason I got these was because they have the contacts so that the camera body can still control the aperture for "-A" lenses.

These actually worked pretty well. Here's a shot I took with a 100mm FA lens and one of the 2x TCs.



The above shot was taken on a cloudy/rainy day, outside, and I had an umbrella partially over my head.

But then, one night, I was messing around with this TC and a DA 35mm lens, and found that when I shot while I was sitting under the lights above our kitchen table I'd get really bad flaring:



I posted about this here:

https://www.pentaxforums.com/forums/58-troubleshooting-beginner-help/315147-s...convertor.html

As mentioned in that thread, i was able to eliminate most of the flaring by using a makeshift hood and got:



So if you get this TC and use it under, say, direct sunlight, be aware of flaring, and if you get it, consider either using a hood, or moving to a shady spot !!
   
Loyal Site Supporter

Registered: July, 2012
Location: Toowoomba, Australia
Posts: 5,469

1 user found this helpful
Review Date: April 23, 2013 Recommended | Price: $50.00 | Rating: 7 

 
Pros: Cheap, can give a useful image within limits
Cons: CA, not for pixel peepers

I picked up this tele-converter in a trade which would have valued it at about $50. Tele-converters are a mixed bag and this one does not have the best of reputations. However, I thought it would be worth testing so that its performance can be roughly benchmarked. The images below give a fair indication of its capabilities. All pics were taken with a K-01 with aperture set manually.

The first set is of a rose bud in the backyard. The first image shows the bud in the centre of the full image. The next two are 100 per cent crops of the central bud taken at about 10 metres with a Tokina rms 400 mm f5.6 (stopped down to f11) and a Pentax M 200 mm f4 (stopped down to f5.6) with the tele-converter ( the effective aperture with the tele-converter is f11). The third image is a 100 per cent crop of the rose bud taken with the Pentax M 200 mm f4 at about 5 metres.

The Tokina has a sharpness rating of 8 from reviews on this site. The Pentax has a sharpness rating of 8.5. Looking at the first and third images, these seem reasonable ratings. The second image, with the tele-converter, shows lack of sharpness and considerable CA. There is also some loss of contrast (the Takumar-A is not SMC).The image degradation caused by the tele-converter is evident. But these are 100 per cent crops. Reproduced on a13 inch monitor (at about 80 dpi) this is the equivalent of a print about 60 inches wide. This is not what the tele-converter would be used for.

So … does the Takumar-A 2x Teleconverter have a place in the camera bag. I believe it does. Imagine you are in the wilds of Australia (like my backyard) and your 18-270 zoom dies. What do you do? Reach into your camera bag and pull out theTakumar-A fitted to a suitable 200 mm or 135 mm lens and continue shooting. The final two images are of a female common wallaroo shot (in the backyard) with the Takumar-A and Pentax M 200 mm f4 on the K-01. The images are 20 percent reductions. They are sharp enough at that size.I would say they are good enough to salvage holiday memories unless one is a compulsive pixel peeper. If one comes up at the right price the Takumar-A 2x may be useful to have in the bag for emergencies or unexpected opportunities.











   
New Member

Registered: September, 2010
Location: Mississauga
Posts: 3
Review Date: April 12, 2011 Recommended | Price: $93.00 | Rating: 7 

 
Pros: Cheeper than buying a telephoto lens
Cons: I think I payed too much for it

I bought this tele-converter at Henry's Outlet in Mississauga Ontario for about 89.00 CDN.
So far I'm happy with the teleconverter, as I'm having fun with it. I think with proper lighting and the right situation I can get some interesting images.

Overall the images produced with it are acceptable.

Here is the first shot I took.


As a photographer I still have a long way to go. But in terms of this tele-converter's performance I think the level of detail and image quality are just fine for my purposes. Since I am a beginner amateur/casual level photographer.
   
Site Supporter

Registered: September, 2010
Location: Hudson Valley, NY
Posts: 2,626
Review Date: September 22, 2010 Not Recommended | Price: $30.00 | Rating: 4 

 
Pros: Allows A setting to be used in K7 camera
Cons: SOFT, SOFT, SOFT!

I was looking for an "A" type teleconverter to use with some older prime lenses that I have for the K7. I have a Vivitar 2x but it does not allow operation in the "A" setting. When I put on the Pentax Takumar A converter on the lens, everything seemed soft! When I switched to the Vivitar 2x, it was sharp! I cannot recommend the Takumar teleconverter unless you are trying to do soft focus work!

Tried the teleconverters on both a SMC 50mm 1.7 and a 135mm 2.5.

BD
   
Site Supporter

Registered: January, 2007
Location: Toronto
Posts: 17,868

1 user found this helpful
Review Date: May 8, 2009 Recommended | Price: $15.00 | Rating: 7 

 
Pros: low cost TC has apature contacts
Cons: there are better TCs out there

picked this up only because it had the apature contacts. I don't really use it, just thought for the price why not.

one thing to note is that while it has apature contacts for the A series lenses, it has no intelligence, apature data is fed straight though which will result in exposure errors on the K10D due to metering.
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