What it may establish
The latest reliably dated ring visible in the spruce, possible relationships with other measured instruments and whether a proposed attribution is chronologically possible.
The history held within the spruce
Every ring
is evidence.
Dendrochronology compares the annual growth pattern of an instrument’s spruce front with dated reference sequences. It can provide powerful, independent evidence about the earliest possible date of manufacture.
Non-invasive photographic analysis€65 · Full refund if no reliable result
What the science can tell us
A precise clue—interpreted with care.
Each year a spruce tree forms a new ring. The changing sequence of wider and narrower rings creates a pattern that can be measured and compared with established, dated chronologies and instrument data.
The reliability of the analysis depends on the quality and visibility of the growth rings, the condition and preparation of the wood, the number of measurable rings and the availability of suitable reference chronologies.
When a statistically convincing match is found, the outermost measurable ring can be assigned a calendar year. This is an important objective finding—but it is not automatically the year in which the tree was felled or the instrument was made.
The findings are an expert analytical opinion based on the material and comparative data available at the time of examination. A result may be approximate or inconclusive and may differ from one obtained by another specialist, laboratory, methodology or reference database. Dendrochronology alone cannot confirm the maker, place of manufacture, authenticity or attribution of an instrument.
What it cannot promise
An exact construction year, the identity of the maker or authenticity from tree rings alone. Seasoning time, removed outer wood and missing rings separate the tree-ring date from manufacture.
Why it remains essential
A strong result supplies independent evidence. It may support the historical picture—or show conclusively that the wood is younger than a claimed maker or label date.
From image to evidence
A disciplined comparison, not a visual guess.
- 01
Measure
Annual-ring widths are measured from sharp, calibrated photographs of the spruce front.
- 02
Cross-date
The resulting sequence is compared statistically and visually with dated reference chronologies.
- 03
Verify
Only a coherent, repeatable correlation is treated as a defensible result.
- 04
Interpret
The date is explained in relation to the proposed maker, label, period and limits of the method.
Your written result
What you receive.
The result is supplied electronically and explains whether a defensible statistical match was obtained, the latest measurable ring identified where possible, and how that finding relates to the proposed date or attribution.
Relevant comparative information and limitations are included where they can be responsibly stated. The result is an analytical opinion, not a certificate of authenticity or authorship. Timing is confirmed after the photographs have been checked and may vary if replacement images or further information are required.
Our result guarantee
No reliable match?
Your €65 is returned.
Some spruce cannot be dated from the available reference material, even when the photographs are excellent. If your images are suitable for measurement but the wood produces no defensible dendrochronological result, we refund the fee in full. If the photographs themselves are insufficient, we will first explain what must be retaken.
Start the testPhotography guide
The quality of the result begins with the quality of the image.
Please send 8–12 original photographs. A DSLR or mirrorless camera with a macro lens is preferred. A modern smartphone may work only if every ring remains crisp when viewed at 100%.
One complete front
Photograph the entire instrument straight-on, with the centre joint vertical and all four edges visible.
Overlapping close-ups
Make a continuous series across both halves of the lower bout, from the centre joint to each outer edge, with 25–30% overlap.
Camera at 90°
Keep the sensor parallel to the photographed area. Use a stable tripod or support, timer and the lowest practical ISO.
Millimetre scale
Place a metric ruler in the same plane as the spruce and keep it visible in the close-ups so measurements can be calibrated.
Sharp, even detail
Use soft, even light without glare. Check every file at 100%: earlywood and dark latewood boundaries must be individually visible.
Original files only
Send full-size JPG, HEIC or PNG files—minimum 12 MP or approximately 4,000 pixels on the long edge. No screenshots, filters or messenger compression.
Questions, answered clearly
Before you submit.
Does the test reveal the exact year an instrument was made?
Not necessarily. It aims to date the latest measurable annual ring in the spruce top. The tree was felled, and the wood was subsequently seasoned and worked; outer rings may also have been removed. The construction date must therefore be later than the dendrochronological date.
Can dendrochronology identify the maker?
Not by itself. It can support an attribution, reveal relationships with other instruments or exclude an impossible date, but authorship also requires expert examination of construction, style, materials, condition and provenance.
What happens if the wood cannot be dated?
If the supplied photographs are suitable for measurement but no statistically reliable match can be established, we refund the €65 fee in full. If image quality is insufficient, we first ask for replacement photographs.
Is the test invasive?
No. Our online analysis uses high-resolution photographs of visible annual rings and does not require a wood sample.