Haystack uses the world's most reliable OCR algorithm to read the text on the paper business cards you scan. When taking a good photo, we expect the scan to capture the text on that card about 98-99% accurately.
If you consistently get lower results, here are some tips & tricks that can help you get better results:
Make sure the text on the card is clear and not blurry
Make sure there is no reflection on the card itself - if you see a reflection, consider taking the photo in a bit of an angle, so the reflection is not on the card
Try to avoid shadows across the card - if you see the phone's shadow over the card, consider taking the photo in a bit of an angle so the shadow does not go over the card
Note: If you hold the camera and the card text is blurry, pull the phone away from the card until the point the text becomes clear - don't worry if the card is further away from the camera - modern phones have great resolution, so the distance should not impact the scanning results.