Does "merge in Photoshop" always mean HDR?

[MiqsPix]

I have CS4 and am familiar with HDR techniques either with Photoshop or Photomatix.* But occasionally I hear of images being "merged" in Photoshop and don't know if this means HDR, or using different exposures and/or layers to create an image in another way.* Can anyone educate me on this please?

[zona5101]

you can merge to create a panoramic...you can merge to create extended depth of field...to correct lens distortion and as you noted to create HDRs. I am sure there are even more reasons...

[dakwegmo]

Photoshop has two at least four merge commands: "Merge to HDR...", that creates a high dynamic range image, and "Photomerge" which stitches photos together to create a higher resolution composite than you could get from a single shot. Photomerge is often used for panoramas and such. And in the layers pallet "merge down" which combines the currently selected layer with the one below it, and "merge visible" which combines all the layers that aren't hidden.

There's also an option for stacking images, that can be very useful for manipulating depth of field (i.e.focus stacking), or removing unwanted elements from an image, such as people from a popular tourist spot.

[jml79]

A question from a Gimp user - Can you not merge layers in photoshop? Or Flatten the image?

[dakwegmo]

Originally Posted by jml79

A question from a Gimp user - Can you not merge layers in photoshop? Or Flatten the image?

Yes you can.

[Krusty79]

They could be referring to exposure blending, where you take one shot of the darker areas and another shot exposed for the brighter areas, combine both in PS and use layer masking to keep just the correctly exposed parts of each image.