Geograph - photograph every grid square

Not all submissions have EXIF details attached, some image manipulation software strips the EXIF unless you ask it not too. Some contributors deliberately strip the EXIF as an easy fix to portrait images appearing sideways on the site.
Where it exists you can use a browser add-on to view the EXIF or download the photo (not the smallest version when larger ones are available - the next size up will have it). In Windows right-click on the photo in question and select 'Properties' then 'Details'. On macOS, open the photo in Preview, click on 'Tools' up in the menu bar at the top then select 'Show Inspector' and click on the 'Exif' tab. In Irfanview use the 'Image information' button.

You can upload images of any dimensions, portrait or landscape, but the file size needs to be under 8 megabytes. We do resize them so their longest dimension is 640 pixels on the main photo page. Optionally, you can also release larger versions of various sizes for downloading and re-use.
http://www.geograph.org.uk/article/Larger-Uploads-Information

We only accept JPEG encoded images. If you have any image in another format it will need to be converted.

Ideally images shouldn't have a longest dimension of fewer than 480 pixels. While we might accept such images if they hold particular interest, we would really prefer a larger image.

We do record the EXIF headers from your original image, so it is advantageous to upload your original camera image or use image editing software that maintains the EXIF data if you want this information to be kept (but we don't currently make use of the data).

Most GPS receivers allow you to change the datum and display format to OSGB36 and British National Grid, the convention used by the Ordnance Survey of Great Britain. If you're using a GPS built into a mobile phone, this may not be possible, and your coordinates will always be in WGS84 lat/lon format. If you also use your GPS phone to take your geographs, it should store the positions in the GeoExif header, which Geograph should interpret correctly as camera position (via the Geotagged Image option).

Otherwise, you can use the map part of the submission routine ('locate/find on map') and enter your lat/lon coordinates in the format the 'Search' function, in decimal degrees like 56.45657,-4.54675 . This will look up the grid reference for the location and insert it as _subject_ position into the submission dialogue. You may have to adjust this unless the subject was right in front of you.

Alternatively, there is a conversion tool here on Geograph Tools http://www.nearby.org.uk/coord.cgi?f=conv from which you can copy and paste. Or one built into geograph at https://www.geograph.org.uk/latlong.php

(Question asked by Roga and answered by barryhunter, oasthouse and DHL on the forum http://www.geograph.org.uk/discuss/index.php?&action=vthread&forum=18&topic=13483&dontcount=1&page=0#1
Later updated, as conversion tools have changed over time))