Equality Clause For Char Match

I am having a hard time having restrictive matches on an equality select where nchar is involved.

The table is:

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[Download_Hash_Log](
[log_id] [int] IDENTITY(1,1) NOT NULL,
[hash_value] [nchar](16) COLLATE Latin1_General_BIN NOT NULL,
[log_date] [smalldatetime] NOT NULL,
CONSTRAINT [PK_Download_Hash_Log] PRIMARY KEY CLUSTERED
(
[log_id] ASC
)WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]

There is exactly one row in the table. It has value 1234567890123456 for hash_value column.

SELECT *
FROM Download_Hash_Log
where convert(varbinary,hash_value) = convert(varbinary,N'1234567890123456')

returns the row - Good.

SELECT *
FROM Download_Hash_Log
where convert(varbinary,hash_value) = convert(varbinary,N'12345678901234')

doesn't return the row. Good.

SELECT *
FROM Download_Hash_Log
where convert(varbinary,hash_value) = convert(varbinary,N'123456789012345')

returns the row. WRONG.

SELECT *
FROM Download_Hash_Log
where convert(varbinary,hash_value) = convert(varbinary,N'1234567890123455')

returns the row. WRONG.

Please help me explain why the last 2 conditions are failing. Why is SQL doing a fuzzy match and returning the row even though it is literally different from the stored value? Is it ignoring the last byte?