QP Card

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About QP Card

QP Card - here we share photos that include the millimeter reference scale from the QP Card 101 and 201, available from http://www.QPCard.com/ and many photography and camera gear sales outlets.

QP Cards are used for exposure and focus accuracy checking and setting, for scene lighting white balance checking before exposure, and for white balance setting and color calibration in post capture processing.

The QP Card 101 and 201 also include a millimeter reference scale for us to inspect and compare full size and 100% pixel view crops so we can assess focus, comparative magnification, and resolution.

Here in this group, please remember to include relevant EXIF and manually recorded image capture data, such as:
- handheld or tripod;
- mirror lockup;
- antishake setting;
- subject distance (and subject stability);
- focal length;
- aperture;
- shutter speed;
- ISO;
- sensor size;
- other camera settings;
- image conversion and manipulation software and settings
- anything that helps us put the reference images in proper comparative context.

The goal? DETAIL ACCURACY! We wish to know if any gear or technique helps or hinders the potential accuracy of our lens-based photographic capture. (Pinhole camera system images are also welcome - comparing QP Card images may be an excellent way to tune pinhole capture choices.)

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Also welcome and invited are other resolution chart pictures, but since they are not as easy to use in the field as QP Cards, be prepared to have them be unverifiable in the next person's experience:

- 1951 and later USAF Contrast Resolution Target and Resolving Power Charts - printed in black, red, yellow, and blue to test for chromatic aberration and at 90° for testing astigmatism, and positive and negative slides ...

- IEEE Target method of characterizing the amount of fine detail (resolution) that a camera system is able to reproduce from an original image ...

- Opal Glass with Crossline Reticle Target - for resolution, focus, boresight, and calibrating machine vision cameras ...

- Variable Frequency Targets - for resolution, field distortion, and parfocal stability ...

- NBS 1963A Resolution Pattern Target - National Bureau of Standards positive and negative pattern versus field ...

- I3A/ISO Resolution Test Chart - to test resolution, complies with ISO 12233. monochrome and color, analog or digital ...

Whew - see why we like the simple, pocketable QP Cards? Carry 'em in your camera bag and include one in your first photo in any series shoot, and share them here with all EXIF and relevant data, and we'll compare 'em to (hopefully) a growing history of other images and data that promises to help inform our gear and technique accuracy choices.

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For tone and chrome accuracy studies using the QP Card 102 (gray scale) and QP Card 201 (color), and the various color checker cards from Gretag Macbeth, Edmund Optical, and others, and various 13% to 18% gray and color cards form Kodak, Fotowand, and others, you may also find a wealth of shared experience and exploration if you visit our Flickr sibling group: http://www.flickr.com/groups/colorchecker/

Enjoy!

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This is a completely free and independent group NOT associated in any way with:

QPcard AB
Mailing Address:
Box 9229
S-40095 Goteborg
Sweden

Visiting address:
Datav. 14 A
S-43632 Askim
Sweden

Phone +46 (0)31 748 44 90
Mobile +46 (0)705 46 94 84
Fax +46 (0)31 69 42 50

E-mail info@qpcard.com

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PS - For freedom from distortion checking and MTF modulation transfer function checking, perhaps we can built ad hoc DxO and MTF groups?

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