Master Knowledge Base & Frequently Asked Questions

Unlike generic image search engines, the app does not merely match the overall coin silhouette with an image archive. It examines key numismatic features: * Obverse and reverse engravings, ruler portraits, coats of arms, and legend lettering. * Date numeral typography, mintmarks, mintmaster initials, and assayer marks. * High-point wear patterns (relief sharpness, portrait hair details, eagle feathers). * Traces of original mint luster, cabinet toning/patina, and mechanical surface marks.

Each report structures the assessment into 6 clear steps: 1. Basic identification: issuing country, denomination, year, mint, ruler, metal alloy, and catalog weight. 2. Reference catalogs & rarity: standard catalog references (e.g., Krause KM, Kopicki, Gumowski) and rarity ratings (R to R8). 3. Varieties & mint errors: verification of die varieties, cracks, chips, and strike alignments. 4. Indicative condition grading: preliminary grading on the 70-point Sheldon scale (from circulated Poor to uncirculated Mint State). 5. Surface assessment: evaluation of fields, toning integrity, and evidence of improper cleaning. 6. Market price ranges: realized price benchmarks from recent completed auction sales in the chosen market.

Yes. No software or computer vision model can replace an experienced numismatist inspecting a coin in-hand with a magnifying loupe. Extremely worn coins (grades 1–3), coins smoothed by decades in pocket circulation, dug metal-detecting finds with ground corrosion, or contemporary counterfeit pieces can be difficult to interpret from a photograph alone. How to help the app deliver the most accurate result? * Select your specific market (from 121 available regions) – the system will focus on auction records and varieties specific to your region. * Enter a hint in the additional text field – if you know the suspected year, mintmark, or visible letters, enter them before initiating analysis.

Good lighting and focus make all the difference: 1. Diffused or indirect daylight: avoid direct camera flash, which creates harsh white glare and hides fine relief. Indirect daylight by a window or a desk lamp positioned at a 45-degree angle works best. 2. Dark, matte background: place the coin on a dark, non-reflective surface (e.g., black paper, felt, or velvet pad). 3. Align with the camera reticle: position the coin inside the circular viewfinder so the rim is completely visible and not cropped. 4. Capture both sides: obverse and reverse are equally important for determining date, mint, and true grade.

The most common reasons are: * The image is blurry, out of focus, or taken in low lighting. * Light reflections obscured crucial details (such as the date digits or mintmark). * The coin is severely worn and missing readable relief details. * The item is not a recognized coin or banknote (e.g., car wash token, souvenir medal, button). In such cases, clean your phone camera lens, place the coin on a steady flat surface, use side lighting, and enter any visible letters or dimensions into the notes field.

**Never clean a coin using chemical solutions or polishing abrasives.** * Cleaning coins with brushes, baking soda, vinegar, or commercial silver dips permanently strips away original mint luster and natural toning. A cleaned coin loses between 50% and 90% of its collector market value, and professional grading services (NGC, PCGS) will return it with an undesirable "Details / Cleaned" grade. * The app is trained to recognize coins with natural patina, toning, and honest circulation wear. Polishing is never required.

Yes. The analysis checks for genuine production anomalies created at the mint: * Die Chips (retained metal buildup): such as the well-known die chips beside numeral 2 on French 2 Euro coins (Tree of Life) or circulation error coins. * Die Cracks: raised, hairline relief lines across coin fields caused by a fractured striking die. * Rotated Dies (upside-down or misaligned): rotational angle offset between obverse and reverse (e.g., 45°, 90°, or 180° medallic/coin alignment). * Off-Center Strikes: misaligned planchet feeding resulting in an asymmetric blank crescent rim. * Doubled Die (DDO/DDR): distinct visual doubling on inscriptions or portrait profiles.

Collector market value is determined primarily by preservation state, not just the date: 1. Condition grade (Sheldon Scale 1–70): a coin in flawless Mint State (MS 65 with full luster) may command $1,000, while the same coin in heavily worn condition (VF 20) might be worth only $5. 2. Rare die variety: minor differences in a mintmark dot, tail feather count, or numeral font create distinct catalog varieties sought after by specialists. 3. Mint errors: error coin collectors pay substantial premiums for verified die chips, rotations, or off-center strikes. 4. Original toning vs harsh cleaning: untouched coins with original cabinet toning consistently achieve higher prices than chemically stripped pieces.

* In-app grading: an instant, preliminary condition estimate generated from photos in seconds. It helps you quickly screen inherited, purchased, or detected coins to see if they warrant professional submission. * Third-party grading (NGC, PCGS, ANACS): requires physically mailing the coin to a secure facility, examination by professional numismatists under stereo microscopes, metallurgic testing, and encapsulation into a sonically sealed plastic holder (slab).

The app provides official catalog alloy specifications for the identified issue (e.g., .900 gold or .835 silver). Please note: no digital photo can measure internal metal density or core composition. Modern counterfeits can be gold-plated over tungsten, brass, or lead cores. To verify bullion authenticity with certainty, check precise weight on a 0.01g jeweler scale, verify dimensions with calipers, perform specific gravity/Fisch ruler testing, or have it examined with an XRF spectrometer.

Original mintage figures simply record how many pieces were struck. True rarity is governed by the modern Survival Rate: Many historical issues with multi-million mintages were melted down en masse during wartime, economic crises, or currency recalls. Consequently, a coin with an original mintage of 2,000,000 can be far rarer and more valuable today in uncirculated grade than a coin with an original mintage of 50,000 where most survived in vaults.

The app sums individual retail auction valuations for each piece in your virtual collection. If you sell an entire collection in bulk to a local coin dealer or pawn shop, expect an offer 20% to 40% below the sum of individual auction estimates. Dealers bear operating overhead, insurance, auction consignment fees (usually 15–20%), and capital holding costs while finding individual buyers.

No. App valuations represent an estimated price range derived from recent completed auction transactions. The ultimate price realized at auction depends on bidder demand, seasonality, auction house reach, lot presentation, and buyer competition.

When switching the camera to Banknote mode: * The reticle adjusts to an elongated 1.8:1 aspect ratio tailored to international banknotes. * The app includes an automatic 90° rotation feature – banknotes photographed vertically are automatically leveled to horizontal orientation. * The algorithm inspects paper fields, margin boundaries, corner sharpness, and print alignment.

* Denomination, currency unit, issuing central bank, emission date, and official signatory titles. * Serial numbers: identification of collector-grade patterns (e.g., radar palindromes 1234321, solid repeating digits 7777777, low serials 0000015, and replacement star/prefix series). * Paper preservation: handling folds, center creases, corner tears, pinholes, and bank counter marks (referencing PMG standards). * Visible watermarks, microprinting, and security threads.

The user interface is localized into over 120 languages (including 73 comprehensive numismatic dictionaries covering Latin, Cyrillic, Asian scripts, and Arabic right-to-left RTL mode). Furthermore, the AI analysis report can be generated in your native language without restrictions.

Coin values differ between national markets. In the side drawer, you can choose from 121 country markets to target local auction archives: * Poland: OneBid, WCN, Marciniak, Niemczyk, Allegro. * Czechia & Slovakia: Aukro, AUREA, Macho & Chlapovič. * Hungary: Darabanth. * Scandinavia: Tradera, MISAB. * Germany & Western Europe: Künker, MA-Shops, CGB, Sixbid. * US & Global: Heritage Auctions, Stack’s Bowers, eBay.

The notes field allows you to provide extra context directly to the system. The principle is straightforward: the more verified details you supply, the more specific and accurate the resulting analysis. Helpful details include: * Suspected year or mintmark (e.g., "1794 Warsaw"). * Observed error (e.g., "Die chip by numeral 2", "Possible 180° rotation"). * In-hand physical measurements (e.g., "3.10 g, 19.2 mm"). * Visible fragments of worn inscriptions.

Yes. NumiStudio AI operates on a transparent Freemium model: * Every new user receives a free starter scan allowance to test all core features without entering payment card details. * An optional PRO / Collector Pass subscription is available for active collectors, offering unlimited scans, deep error analyses, and full collection management.

The app uses an Offline-First local storage architecture (IndexedDB): * Your photos, scan history, and collection vault remain stored directly in your smartphone's local memory rather than exposed public servers. * Your collection remains private, and you can clear your history anytime with one tap.

Because data resides locally on your device: 1. Open the side menu in the app (Collection Vault). 2. Tap [ Export Collection / Backup ] to download a JSON archive or PDF summary to your Google Drive or computer. 3. On your new phone, import the backup file to instantly restore your entire collection history.

Billing is processed entirely through Google Play: 1. Open the Google Play Store app on your Android phone. 2. Tap your profile icon (top right) ➔ Payments & subscriptions ➔ Subscriptions. 3. Select NumiStudio AI and tap Cancel subscription. (Uninstalling the app does not automatically cancel an active Google Play subscription).

If you switched phones or reinstalled the app: 1. Ensure your device is logged into the same Google account used for the purchase. 2. Open NumiStudio AI, go to the side drawer, and tap [ Restore Purchases ]. 3. If issues persist, contact support at kontakt@numistudioai.pl with your Google Play order number (starting with GPA.).

No. We do not sell user data, track GPS locations, or share photos with external marketing brokers or third-party dealers. We comply with EU GDPR regulations and Google Play Developer Policies.