Hobbies
Coin Magnifier App for iPhone [Mint Marks at 40x]
A coin magnifier app turns your iPhone camera into a digital loupe for reading mint marks, judging wear and spotting doubled dies or signs of cleaning. These details are small: a mint mark is often about a millimeter tall, and the difference between a VF-30 and an EF-40 grade comes down to light wear on the highest points of the design. Collectors traditionally use a 5x to 10x loupe and a good lamp for this.
How LoupeLens helps
LoupeLens magnifies up to 40x and keeps the flashlight on while you zoom. Press and hold the flashlight button and slide to dim it, which stops shiny silver and proof surfaces from turning into a white glare spot. Tilt the phone so the light reaches the coin from a low angle, and wear, hairlines and the edges of a mint mark show up as small shadows. Tap to take a photo of what you see; captures go to a LoupeLens album in Photos.
Real situations
Checking Mint Marks at a Coin Show
At a dealer’s table, open LoupeLens, zoom to about 8x on the date area and read the mint mark with the light dimmed. Take a photo so you can compare it with a variety guide later. If you are not sure where the mark sits on a given coin, the mint mark chart lists the position by coin and year.
Detecting Cleaned Coins
Cleaned coins are usually worth much less than untouched ones. At 6x to 8x with light from the side, cleaning shows as fine parallel hairlines across the fields, or as a bright, flat surface on a coin that should have toned.
Documenting Your Collection
Photograph each coin’s obverse, reverse and any notable detail when you get it, for insurance records, sale listings or your own catalog. Use the same zoom and flashlight level each time so the photos are easy to compare.
Verifying Online Purchases
When a coin arrives from an online seller, check it under magnification straight away and compare it with the listing photos. If something does not match, your own close-up photos give you something concrete to send back.
Compared with the alternatives
Traditional loupes (10x to 20x) are compact and optically sharp, but need good external light and a steady hand, and they cannot take a photo. USB microscopes offer high magnification but need a computer and stay on the desk. The built-in iPhone Camera app can zoom, but you cannot dim its light while you look. LoupeLens puts magnification, an adjustable light and photos in one app on the phone you already carry. To find the mark itself, see the mint mark location chart.
Frequently asked questions
Is 10x enough magnification for coin grading?
Yes. Collectors and dealers typically grade with a 5x to 10x loupe. Mint marks, repunched marks and doubled dies are easier at 20x or more. LoupeLens zooms up to 40x; above 10x, rest the phone on something steady.
Can I photograph coins with LoupeLens?
Yes. Tap to take a photo or hold to record a video while zoomed in. Captures are saved to a LoupeLens album in Photos, which makes them easy to find for a listing or your records.
How do I light coins properly with LoupeLens?
Set the flashlight to a low or medium level and tilt the phone so the light reaches the coin from the side rather than straight down. This shows surface texture, wear on the high points and hairlines from cleaning.
Where is the mint mark on my coin?
On most US coins made since 1968 it is on the front, close to the date or the lower edge; on older coins it is usually on the back. The mint mark location chart gives the exact spot for each coin and year.