Data sheet: Expert 35 mm f/2.8

Pekka Buttler, 03/2026

Specifications

The table below summarizes the lens’ key specifications (Measurements based on pictured sample):

Brand:	Expert	Lens name	1:2.8 f=35mm
Focal length(s) 1	35 mm	Angle-of-view 2	64 °
Maximum Aperture	f/2.8	In Production	turn of 80s
Lens mount (this lens)	Olympus OM	Other lens mounts	uncertain3
Length 4	48,3 mm	Diameter 5	65,0 mm
Filter ring diameter	52 mm	Weight	277 grams
Lens element count6	6	Lens group count	6
Aperture blades (S/R/C) 7	5 S	Focus throw	150 °
Minimum focusing distance (measured)	31 cm	Maximum magnification (measured)	1:5,8
Has manual aperture ring	YES	Has Manual focus ring	YES
Aperture mechanism type	Auto	Aperture click stops	2.8•4•5.6•8•11–16

Further notes:
• First off: ‘Expert’ is not a lens manufacturer, but a rebrander (see more below).

• This Expert 35 mm f/2.8 is with a high likelihood a Tamron lens, but rehoused in a way common to a batch of lenses Tamron made for rebranders in the late 70s.
• This lens is unusually large and heavy for what is a decidedly modest-spec lens

History of Expert

Expert was not a lens manufacturer but a rebrander. Expert is/was a giant, European electronics retail chain that for some time also sold lenses under their own house brand. You can read more in the JAPB company profile on expert.

Versions

It is more than likely that this lens existed also in other mounts than Olympus OM, and in that case the measurements of those lenses may differ slightly.

Expert also offered altogether two 35 mm f/2.8 lenses, namely:
• Expert 35mm f/2.8 (pictured lens)
• Expert 35mm f/2.8 MC

Both of these lenses have the same outward cosmetic appearance and the only difference is in whether you’re dealing with a multicoated or single-coated lens.

Adapting

We’re going to be discussing adapting Olympus OM mount lenses. If your copy of the Expert 35/2.8 sports another mount, please study the JAPB article on the requisite lens mount for adapting tips.

This lens cannot be used natively on any current SLR or dSLRs. To use it in its native environment, you will need an Olympus OM film body. Luckily there are a lot of those available, as they remained in production into the 2000s.

Thanks to being a fully manual lens (manual aperture, manual focus), the lens can be adapted to all mirrorless cameras using a suitable adapter. Moreover, a simple ‘dumb adapter’ will do the job perfectly. While the OM mount has been popular, special adapters are not easily available, but one can choose to daisy-chain adapters (e.g. OM->Canon EF; Canon EF –> mirrorless) which also opens up a wide range of special adapters (speed boosters, helicoid adapters, tilt/shift adapters).

Using Olympus OM lenses on dSLRs can also be an easy option, depending on which dSLR.
• Canon EF has the shortest flange focal distance among full-frame dSLR’s and Canon’s wide range of dSLRs are able to Mount Olympus OM lenses perfectly using a simple adapter ring.
• Sony/Minolta A, Pentax K and Nikon F dSLRs are able to use Olympus OM lenses using an adapter that uses corrective optics to allow infinity focus.

Footnotes

1. Focal length is (unless stated otherwise) given in absolute terms, and not in Full-frame equivalent. For an understanding of whether the lens is wide/tele, see ‘Angle-of-view’. ↩︎
2. Picture angle is given in degrees (based on manufacturers’ specs) and concerns the diagonal picture angle. Rule of thumb:
   > 90 ° ==> Ultra-wide-angle
   70–90 ° ==> Wide-angle
   50–70 ° ==> Moderate wide-angle
   40–50 ° ==> ‘Standard’ or ‘normal’ lens
   20–40 ° ==> Short tele lens
   10-20 ° ==> Tele lens
   5-10 ° ==> Long tele lens
   < 5 ° ==> Ultra-tele lens ↩︎
3. Expert-lenses were usually available in the typical lens mounts of the era (M42, Canon FD, Konica AR, Minolta SR, Nikon F, Olympus OM, Pentax K), but it is not certain that each lens was offered in everyone of these mounts. ↩︎
4. Length is given from the mount flange to the front of lens at infinity. ↩︎
5. Diameter excludes protrusions such as rabbit ears or stop-down levers. ↩︎
6. Data on lens elements and groups is based on a single source. Alternatively, it might also be a 4 elements in 3 groups design. ↩︎
7. S=straight; R=rounded; C=(almost)circular at all apertures. ↩︎