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Tamron (adaptamatic/fixed mount) 300mm F5.6 Review RSS Feed

Tamron (adaptamatic/fixed mount) 300mm F5.6

Sharpness 
 9.0
Aberrations 
 7.3
Bokeh 
 8.3
Handling 
 8.0
Value 
 9.8
Reviews Views Date of last review
4 26,565 Sat February 11, 2023
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Recommended By Average Price Average User Rating
100% of reviewers $44.75 9.25
Tamron (adaptamatic/fixed mount) 300mm F5.6

Tamron (adaptamatic/fixed mount) 300mm F5.6
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Tamron (adaptamatic/fixed mount) 300mm F5.6
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Description:
The adaptamatics were the precursors of the Tamron Adaptall swappable mount system. The two systems are completely different. Adaptamatic mounts can be found for: C-AF for Canon (FL fit, usable on many FD cameras with restrictions); EX for Exakta bayonet; M42 screw thread; N-IF for Nikon F, F2, Nikkormats etc (pre-AI); M-A for Miranda F, G, Automex Ill and Sensorex ; SR (no meter coupling) and SRT (meter coupling) for Minolta ; K-A for Konica Autoreflex; P-E for Petri; T-O for Topcon.
Note: PK came later so no PK (use M42 + adapter).
The mount locking ring is a M58 thread - this DIY article discusses diy mount possibilites.

Scan of original adaptamatic user manual here.
Scan of user manual and original brochure can be found here.


"Tamron Adapt-A-Matic 300mm F/5.6 Model 670Au: This lens was available in three versions. Production obviously started sometime before 1972 as indicated on Tamron's web site. We are not sure if the 670Au model name applies to all three versions. Initially there was the first model which featured a metal knurled focus ring. Then there was a subsequent model which featured a rubber focus ring yet still did not have slots on the aperture ring for the aperture coupling band included with later versions of some Adapt-A-Matic mounts. The final version of this lens featured a rubber focus ring plus the slots for aperture coupling bands." Adaptall-2.org.

The general consensus online is that when the adaptall system started in c.1973 this (and the 200mm adaptamatic) was equipped with the adaptall mount. This lens is therefore the same as the version 1 of adaptall 300mm f5.6 - and the pic shows a silver version adaptall-1 300mm for comparison. A later version was introduced c. 1976 - the CT300, and that is the one pictured in the adaptall CT300 review and described here - lighter, more compact and no tripod mount but otherwise similar optical specification.

Lens Model:670Au
Focal Length:300mm
Aperture Range:f/5.6 - 22
iris blades:9
Angle of View:
Optical Construction:2 groups, 4 elements
Min. Focus from Film Plane:98" / 2.5m
Focus throw:~ 200 deg rotation
Filter Size:62mm
Diameter:2.8" / 70mm
Length approx:8.0" / 203mm
Weight:28.0 oz. (795g)
Lens Hood:Built-in
Tripod Mount:built in.

Also sold as other marques; Bushnell, Rokunor, vernon Edonar (these with fixed mount), and (according to the "Cult Classics" writer), Accura and Spiratone. Fixed mount versions can be found too ("Vernon Edonar" - front end pic above )
Mount Type: Third-party (adapter required)
Price History:



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Pentaxian

Registered: February, 2014
Posts: 405
Review Date: February 11, 2023 Recommended | Price: $30.00 | Rating: 9 

 
Pros: sharp!
Cons: minor CA
Sharpness: 9    Aberrations: 7    Bokeh: 8    Handling: 9    Value: 10    Camera Used: KP   

Wow!
I have been searching for a decent prime 300mm lens for ages.I have a superb Canon 300mm f2.8, adapter to PK, and minus all the electronics, which means it is converted to manual focus, and no diaphragm. So everything is at 2.8, and yes, the lens is very sharp. BUT, the lens is seriously heavy, and not exactly hand-holding friendly.

So I've been searching , and bought a Zeiss 300mm f4 'Olympic' Sonnar version 1. Sharp, but terrible CA wide-open. Plus it is somewhat heavy. Then I bought a Russian Tair f4.5, and yes, reasonably sharp full aperture, and low CA. Very hand-holding friendly.
So I kept looking, and today a Tamron Adaptamatic 300mm f5.6 arrived with m42 mount. Needed a serious clean, fungus everywhere, but ended up spotless. And boy is it sharp-close to the Canon, expecially at f9 and above.Marginal CA, and very useable. It also has a tripod bush, but frankly it is very easy to hand-hold so you don't need it.

So if you find one going cheaply, buy it! Mine cost all of £20.
   
New Member

Registered: March, 2021
Posts: 3
Review Date: June 12, 2021 Recommended | Price: $40.00 | Rating: 10 

 
Pros: Sharp, good colour
Cons: Its big
Sharpness: 10    Aberrations: 8    Bokeh: 9    Handling: 6    Value: 10    Camera Used: Canon RP / pentax es-II   

This lens is absolutely underated it is at f/8 sharpness is comparable my canon RF 70-200 f/4L. It definitely has its weight to it but it is manageable and if you do wildlife on a budget get this lens you wont regret it.
   
Site Supporter

Registered: November, 2012
Location: North Wales
Posts: 2,858

2 users found this helpful
Review Date: March 9, 2014 Recommended | Price: $40.00 | Rating: 9 

 
Pros: Classy, better performing than its (non-OEM) contemporaries, vintage prime. Value!!
Cons: Limited choice of mounts - prefer the optically identical Adaptall version 1 with PK/PKA mount. Focus rotates front end, could do with just a touch more damping.
Sharpness: 8    Aberrations: 6    Bokeh: 8    Handling: 9    Value: 10    Camera Used: K-r, GX20   

Of the handful of bargain basement 300's I have had a look at this lens, IMO, is the nicest. I have primarily compared with some of those (eg Photax 300mm f5 I have also reviewed) and with my SP 300mm adaptall 54B.

Mechanically this lens really is a lovely piece of kit. Focus is super smooth (but a touch light, creeps if lens is held vertically), one up on the focus on my 54B, which I find twitchy and too short in its throw. Hood is nice and snug and a good size, tripod mount is solid. More user friendly and half the weight of my Tair 3, I have no problem carrying it around and had decent success hand held or on a monopod.

Optically the lens yields little in sharpness to the 54B, putting similar pics side by side. However the 54B is better wide open, has slightly better contrast, and a better (warmer) colour balance, the adaptamatic being distinctly cool/blue. I would like to be able to add that the 6 element SP 54B was superior in terms of CA - purple fringing - but I can't, because it isn't. PF is a weak point for that lens. The adaptamatic showed significant PF eg on some shots of the backlit castle towers, high contrast road sign: a longitudinal CA susceptibility - the fringing changing colour with slight front/back focus. These simpler optical constructions will, I think, always tend to be prone to some fringing. Stopping down helped.

54B is also designed for good close focus performance. Distant CFD's is a feature of the older lenses, 4-5m is typical, this does much better than that at 2.5m but still short of 54B's 1.4m. It's not a lens I've looked at for close focus really.

Compared to the generic brand and preset 300's, most specifically wide open, this was consistently sharper, less prone to coma/halo. Indeed I found this example very usable at f5.6 unlike the generics which really needed to be stopped down - better than indicated by the review below.

sample pic - Samsung GX20 jpg, contrast buffed, sharpened to compensate for resizing.




There is no PK mount in an adaptamatic fitting, the most common mount that these come with is M42. Nikonistas can search for the F mount, good luck cos they're a bit scarce, but worth the effort to avoid Nikons' infinity focus issues with M42.

This lens crops up fairly regularly but is roughly half as common as the adaptall-1 300mm's, whose average price I would put at ~50% more (and 54B is typically 3x-4x the price). The argument between this lens and the adaptall mount 300's probably depends on overall cost, size and weight (795g vs 580g for the CT300, 20cm vs 16cm), and how you like working with M42 mount lenses, which will probably depend on your camera model. On my K-r I habitually work with Av mode, stop down metering. In principle this is fine, in practice the K-r, demands levels of exposure compensation that verge on impractical: I am routinely maxed out at +3eV* (the K5 that replaced the K-r is much better in this respect). I do much better with a PK/PKA mount on an adaptall lens. And in respect of the latter, unlike the consumer zooms where the cost of a PKA means that the value equation can be unfavourable in comparison to a readily available fixed PKA mount equivalent (eg the compact Tokina SD 70-210mm, versus the compact adaptall 70-210mm 58A), in the 300mm prime lens arena there are hardly any 300mm f5.6 PKA mount alternates (the only one I can think of is the uncommon late model tokina SL300) at an equivalent price.
In any case once you've got one adaptall lens you're very likely to be interested in getting some more so the PKA mount becomes a more worthwhile investment. However that still leaves a big difference between the cited average price for this and ballpark estimate ~$100-150 for P-KA + CT300/54B. This Adaptamatic is the bargain basement choice.

*See my thread on "painted vs Plated mounts".
For more on this lens I refer you to Luis Alegria review on mflenses.

More pics here; here.

UPDATE I have now acquired a nice example of the adaptall version 1 300mm f5.6, which is basically this lens with an adaptall mount, so reluctantly decided to move on the adaptamatic.
   
New Member

Registered: February, 2013
Posts: 8

4 users found this helpful
Review Date: March 5, 2014 Recommended | Price: $69.00 | Rating: 9 

 
Pros: Great build quality, good contrast & sharpness when stopped down to f/11 - f/16, built-in tripod mount & hood
Cons: Low contrast when f/5.6 - f/8, a bit heavy
Sharpness: 9    Aberrations: 8    Handling: 8    Value: 9   

This big “beast” has impressive build quality and a very solid feel. Mine came with a FD mount.

The built-in tripod mount is great and necessary for the lens weighs 830 grams (without the caps). The built-in hood is also a great plus but tends to slide back when shooting upwards (maybe the hood of this copy is worn-out).

IQ:

f/11, f/13, f/16: Excellent sharpness and contrast. f/22 still very good!

f/9: Sharpness very good, contrast good

f/8: Sharpness good, contrast low

f/5.6: Sharpness low, contrast very low

Mild chromatic aberration throughout—very good for a lens from early 70's.

Sample shot - f/8, shot in RAW, contrast/sharpness adjusted in post-processing:



Quick test - f5.6-f9:



Quick test - f/11-f/22:


And here's the lens:
Add Review of Tamron (adaptamatic/fixed mount) 300mm F5.6



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