I just installed Gramps the other day and am rather new to it. When I go to Pedigree view, it only shows me five generations at a time. How do I change this (as in make it show more)? Or is it not possible?
With the proviso that I am still using Gramps 3.4.1 on Windows (because I use it as a Portable App) the change you want is quite straight forward.
In the Ancestry mode, select View then Configure View.
Then move the slider to the right as far as you can cope with the necessary scrolling that results.
Although not exactly what you are looking for (@Fortiter just provided that in his answer), you can see many generations at once using reports. That can provide context for the fewer-generation view in pedigree. Just keep it open in another window while you are navigating around using pedigree.
Reports - Graphical Reports - Pedigree Chart: The 'tree options' tab has a 'generations' field. I set mine to 10 and it worked fine. Note you can output either openDocument, svg, postscript, or pdf. You might have to play with sizes (fonts and paper) to get what you want. My first 10 generation pdf was 48 pages which does not meet your original request to see more generations at once. However you can make one big pdf (easier with svg if you have svg viewer) that can.
Another choice is Reports - Graphs - Hourglass Graph. It allows for both ancestors and descendants - since both are configurable, you can set descendants to zero and have just an ancestor chart. Graphs allow a graphviz output (in additions to jpeg,png,pdf,...) which is the underlying graphical engine (see graphviz.org). I like using that so I can tune the output the way I want. For example - prune off a branch you don't want to see is easier in the graphviz file than it is by changing my gedcom. Another example is to combine two graphs. I used this when making a tree of how I was descended from the founders of Scituate, MA. They aren't related and it was easier to combine 5 realtionship graphs than to prune most of my ancestors out of my ancestor graph. This is easier to do visually with graphviz than by changing the gedcom - especially when there are overlaps (eg 3rd cousins marry).
A lot of software will display only four or five generations in its pedigree view, and for good reason; there simply isn't much space to display more. RootsMagic will display six generations, but don't get too excited about that; the boxes that display the sixth generation are rather small.
Gramps' "Configure View..." button brings up a dialog box that lets you increase the number of generation displayed to 9, but there is a trade-off; even on a large screen, a pedigree that large does not fit within the application window, so you have to scroll around.
To view more generations at once, create a chart. Most charting software can handle up to 10 or 12 generations or so, and the on-screen preview mode may allow for interactive exploration of your database.
H-tree pedigree displays 5 generations (31 people) by default, and select the configuration icon in Ancestry mode and move the slider for "Tree Size" to "6" so that it displays 6 generations (64 people) of ancestors on screen at the same time!