My personal journey with Tamron lenses began with the AF 19-35mm f/3.5-4.5, my first independent lens purchase.

While that early experience, with its overlap with my kit lens, might not have been the most practical choice, it ignited a curiosity that led me to explore the brand’s more intriguing offerings.

The Tamron Converto 135mm f/2.8 is a prime example of this exploration, revealing the hidden gems within Tamron’s rich history.

The Converto’s most distinctive feature is its integrated doubler system. With a simple adjustment, the lens transforms from a 135mm f/2.8 into a 225mm lens.

This ingenious design, while making the lens notably longer than typical 135mm lenses, offers a level of versatility rarely seen in vintage optics.

The lens boasts an all-metal construction, exuding a sense of robustness and durability. This solid build quality is a hallmark of vintage lenses, designed to withstand the rigors of professional use.

However, my copy suffers from an extremely stiff focusing ring, a common issue with vintage lenses.

This stiffness, combined with the inherent challenges of the M42 mount, makes precise focusing a delicate and sometimes frustrating task.

Furthermore, I encountered compatibility issues when attempting to remove the doubler while using an M42 to EF adapter.

The situation suggests potential thread differences or mechanical quirks that may affect adapter compatibility.

There appear to be inherent challenges with adapter compatibility when using the lens without the doubler.

The problem could stem from subtle variations in thread pitch or other mechanical factors that are not immediately apparent.

These compatibility issues underscore the importance of careful research and testing when adapting vintage M42 lenses.

One of the most intriguing aspects of the Converto is how the doubler affects its focusing capabilities.

• In its standard 135mm configuration, the lens offers typical telephoto focusing distances
• With the doubler attached, transforming it into a 225mm lens, it achieves near-macro focusing capabilities. This remarkable ability opens up a world of creative possibilities, allowing for close-up shots of subjects that would otherwise be beyond the reach of a standard telephoto lens

I demonstrated this difference by capturing comparative cat photos at both focal lengths, showcasing the dramatic shift in close-focusing ability.

The lens exhibits varying bokeh characteristics depending on the background.

• Against simple backgrounds, it produces a smooth and clean bokeh, rendering pleasingly blurred backgrounds
• In busy backgrounds or with specular highlights, the bokeh becomes more pronounced, with noticeable bokeh balls
• Generally, the bokeh is more subdued compared to some vintage lenses known for their distinctive bokeh rendering
• The bokeh performance also varies between the 135mm and 225mm configurations, offering photographers a range of creative options

• The center sharpness is good at both focal lengths, delivering clear and detailed images
• However, there is a noticeable falloff in sharpness towards the edges of the frame, a typical characteristic of vintage lenses

• Portrait Photography: The 135mm configuration is well-suited for capturing flattering portraits with pleasing background separation
• Wildlife and Distant Subjects: The 225mm configuration is ideal for capturing wildlife or distant subjects, bringing them closer to the frame
• Close-Up and Near-Macro Work: The doubler enables close-up and near-macro photography, allowing for detailed shots of small subjects
• Creative Bokeh Effects: By carefully selecting backgrounds, photographers can leverage the lens’s bokeh characteristics to create visually appealing images

• The Tamron Converto essentially offers two lenses in one package: a capable 135mm f/2.8 telephoto and a 225mm longer telephoto with close-focusing capabilities. This versatility makes it a compelling value proposition for vintage lens enthusiasts
• The potential for macro applications with the doubler further enhances its value

The lack of accessible vintage lens servicing, particularly in regions like South Africa, presents a challenge for users of this lens.

The stiff focusing ring, in particular, would benefit significantly from professional servicing to improve usability.

The Tamron Converto 135mm f/2.8 earns a 7/10 rating.

It’s a unique piece of vintage glass that offers intriguing capabilities and a distinctive shooting experience.

• Two focal lengths in one lens, offering exceptional versatility
• Solid all-metal build quality, ensuring durability
• Near-macro capabilities with the doubler, expanding creative possibilities
• Versatile bokeh characteristics allow for a range of creative effects
• Good value when found at reasonable prices, offering two lenses for the price of one

• Stiff focusing mechanism, hindering precise focusing
• Adapter compatibility issues, requiring careful research
• Size and weight considerations make it less portable than standard 135mm lenses
• Limited serviceability, posing challenges for maintenance

For photographers interested in exploring the world of vintage glass, the Tamron Converto 135mm f/2.8 represents an intriguing value proposition.

While the stiff focusing ring on my copy limits its practical usability, the unique convertible design and optical performance make it a worthwhile consideration for collectors and vintage lens enthusiasts.

It’s a lens that embodies the spirit of innovation, offering a glimpse into the creative possibilities of vintage lens design.