It is and can be difficult to take take indoor jumping pictures. I try not to have to do it at local low level shows do to the fact most of these horses are not in any way used to any type of flash.
Beyond the flash part---your camera must have the capability to have an iso stting of 3200 or higher. Without this capability the likelihood of blurr is increased dramatically.
What are the settings you have the camera set on while taking a photo in outside light while the horse is jumping?
What are your camera setting while indoors?
Outside....things also depend on where the sun is what the backdrop looks like the type of day (cloudy sunny both etc etc)
Inside things can be complicated by different angles of light coming in. Such as, natural light sources as well as artificial light.
What type of lens are you using? A zoom lens? If so what type of zoom.
I am not familiar with the D 5100 but I think.....it may have the capacity to for ISO stting of 3200 or greater. The older model D60 I do not believe can do this. I had 2 D70's and they in no way compared to the capabilities of a the D90
I have learned over the years there are so many factors that come into play when photographing horses doing different things.
The best thing I can suggest is to practice and read your manual.
If you are a new beginer to photographing horses jumping I suggest to master doing it outside first and become familiar with the camera and settings and lighting etc!.
Do you have some sample photos of both indoor jumping shots and outdoor jumping shots? Can you post them?
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