Review: Tamron 24mm f/2.5 Model 01B (Adaptall-2 System)



For some time I have wanted to get my hands on a (cheap) manual prime wide angle lens for astrophotography and have since long had an good eye at the Tamron 24 mm f/2.5 Model 01B but without doing anything serious about it. However, now prices on e-bay appears to be “skyrocketing” also for this relatively "simple" lens. So, the time had come to act. After having lost a couple of auctions that ended just above and just under GBP 60, I won in my third attempt with a bid of 43 pounds incl. postage. The lens arrived after 14 days of anxious waiting. It was sent from the UK by airmail! I presume they must have sailed plane across the North Sea by ship??


After having tried it for a few days, and especially tested it in less-than-perfect lightning situations, I have become so fond of  this little lens that I think it deserves a review.


Now, why  exactly Model 01B?

Well, according to this lens is very good - if not exactly super sharp - right from f/2.5. Furthermore, it should be equally good and equally sharp across the entire image field, already at full aperture - something that I cannot say about several of my other lenses from that era; in particular, they exhibit CA and coma at full aperture. And it doesn’t make much sense to buy a "fast" lens if one immediately has to stop it down in order to get decent pictures.


Then, of course there is also Tamron’s reputation for fine optical and phycally compact designs together with a consistent manufacturing quality at that time. And lastly, they are designed with AE capability which is surely beneficial if you are a Pentax user.



First impressions.


Exquisite build quality and smooth, precise workings of the focus and aperture rings characterize (also) this Tamron Adaptall-2 lens. It is even fairly compact for a 24 mm lens to be, as can be seen in comparison with my Pentax SMC-M 50mm f/2.0 from the same period:

My copy can be characterized as close to "mint". Actually, this may not necessarily always be a good sign as this could also be an indication that it has not been much used in its time - perhaps a poor copy; a purchase in mistake? Well, fortunately the casing that came with my lens shows, that this lens really has been pulled in and out many times, and that the original owner just has taken good care of his gear – and thank you for that


How to test a lens like this?

As I said, I bought this lens because of its wide maximum aperture - and then fact that it is a prime. So, my tests should primarily concern its performance in the dimmer light situationz and with an emphasis on performance around f/2.5 slightly smaller apertures. (Actually with my Adaptall-2 PK-A adapter, I have the following aperture steps to choose from at the lower f-numbers: 2.4 (!), 2.5, 2.8, 3.2, 3.5 and 4.0 --- a little peculiar).


Furthermore, in lack of “un-biased test benches” I always try to shoot my subject under test against other, comparable lenses (to the extent that I have such). So, in this case I shall start shooting against my Vivitar Series 1 24-48 mm f/3.8 zoom lens from the late seventies and my modern AF Tamron 18-200 mm f / 3.5 to 6.3 – well knowing that it is not entirely "fair" to compare primes and zooms, but this is now what I have had for this occasion.

I did run into a problem from the start. Take a look at the composite image below made with my Tamron 01B and the Vivitar and taken from exactly the same vantage point. The Vivitar image, when set to 24mm, is clearly a bit larger than the Tamron image.

A following check with my modern Tamron and a bit of pixel counting confirmed my suspicion: It was the Vivitar image that was too large - as if taken at 28mm focal length. The zoom setting of the Vivitar was very stiff; I got the lens from new but have not used it for ages (hence the stiffness), and I now suspect that there was some internal resistance in the movement of one or more of the lens groups. More use in the days after have made the Vivitar behave somewhat better. Anyway, for this test I have had to use what I had and "as was".

For the following test, I used a 10x15 cm test chart (published on the home page of the "Digitalmagasinet: ):


It is designed to be photographed at a distance of 50 x focal length, in our case 120 cm, and the picture is so tiny (just 600 pixels high on my sensor) and crabbed. It is not "pretty", but here it is comparison that counts.

The Vivitar and the 01B both behave well in respect of focus-confirmation for this target, which the modern Tamron cannot manage at all. Here I must zoom in to catch focus and then zoom out again, but the results shown below are representative of all three lenses after many repeated tests:


The conclusion seems clear: As far as resolution and sharpness are concerned, the Tamron 01B is the clear winner of this test! (It is not without reason that astrophotographers usually prefer primes).

Chromatic Abberation.
First, a picture by the Vivitar at full aperture:

Next, this picture taken with the 01B immediately after and also at full aperture:


Again, the result speaks for itself. It would be wrong to say that the 01B is entirely free of CA in all situations, but it is seen much rarer and to a much lesser extent than with the Vivitar which, in a situation like this, inevitably always exhibits CA.

Reflexions / flares.
Others of my Adaptall-2 Tamron lenses can be quite sensitive towards stray light and directly incident rays from strong sources of light, but not the 01B! It may not be completely immune to flares, but one often has to angle quite a bit to catch them:

Model 01B is characterized by somewhat cooler colors than we know (and like) from for example the Takumars:


If you want warmer colors, it is simply to adjust a little on Hue (less) and Saturation (more) in the camera's setup menu:

- sure, even with old MF-lenses a great many things have become much easier in the digital era.

”Close Focusing”.

This feature I have not seen mentioned in many places, but the minimum focusing distance is small, down to (nearly) 25 cm and that, I think, is a big plus for this lens. Thus, one may use the lens for some close-up photography. As an example, here is a small orchid (the flowers are about 2-3 cm in diameter):

First at f/2.5:


and next, at f/8.0:


Of course, there is a better DOF at f / 8, but I don’t really think that I have something to complain about at f/2.5 either.


Does it make sense to buy a 24 mm lens for an APS-C camera nowadays?

If we disregard the possible use for astrophotography, many will probably answer "no, it is not sufficiently wide to me." However, I find that I could easily use such a lens (corresponding to a 35mm lens for a 35mm film- or modern full-fame camera) in many situations where space is tight; ambient light limited and/or use of flash is not welcome.  And with such a prime one will (re-)discover how much a few steps forth and back can alter the view and composition:



(OK, I have cheated in the last sample and stacked 9 images in Combine ZM, but the basement hallway is about 40 feet long, and if you zoom in on the far end you will  discover that it is the camera's pixel size alone and not the lens, which limits the resolving power at f/2.5)

Street Life.



Arts / exhibitions.


As said, all pictures have been shot at f/2.5 or thereabouts, unless otherwise stated above. This picture was also taken at f/2.5 and if we zoom in(200% crop):


we see that the canvas structure and brush strokes are captured nicely at full aperture.


Landscape and all the other stuff.

You can find more image samples on the following link from a little walk on a late, rather gray and misty November afternoon during the hours on


Summary / conclusion.

For GBP 43 I got a Tamron Model 01B in near-mint condition, original pouch, Minolta-style Adaptall-2 mount (which I connot use), original lens- and mount caps and a Miranda 55 mm skylight filter. Having followed the evolution of prices on e-bay for a while I suppose that one should be prepared to sacrifice a little more these days, but with my first experiences with this lens, I also believe that for a good specimen, a slightly higher price will be OK.


For myself, I have certainly concluded that this lens should be used for much more than just astrophotography.

View: Sample Images Slideshow

Brochure: Tamron 24mm f/2.5 Model 01B (extracts from master brochure)

Manual: Tamron 24mm f/2.5 Ultra Wide-Angle and 28mm f/2.5 Wide-Angle Owner's Manual


Copyright © 2010 - Steen G. Bruun