influence of different ground control markers when running optimize

[bisenberger]

There are three different symbols when placing markers, a yellow flag, a blue flag, and one that looks like a flag viewed from above. What are the influences of the different flags when running optimize to optimize photo alignment?

[Alexey Pasumansky]

Hello bisenberger,

Green flag is used for pinned marker position, it indicated that markers projection was manually specified or refined by user.
Blue flag is used for projections estimated by PhotoScan automatically - in case of Guided marker approach placement, for example, or Track markers procedure for multi-frame chunks.
And grey flags indicates estimated position for marker based on it's projections on photos that were already aligned.

Blue and green flags are used for referencing and/or optimization, whereas grey flags are not. Grey flags have only visualization purpose to help user to find estimated marker projection.

[bisenberger]

Thanks for the info Alexey.
As you could probably tell from my description of the flags, I'm color blind.

[Alexey Pasumansky]

Here is sample image: