Gordon Tarpley/Flickr GoPro shares dropped to all-time lows after the company said it was cutting about 7% of its staff and sales were not great.

In a statement Wednesday evening, the digital-camera maker also announced its preliminary fourth-quarter and full-year 2015 results.

It said it expected fourth-quarter revenue to be about $435 million (versus $511 million expected, according to Bloomberg) and $1.6 billion for 2015 — worse than forecast because of sales that were lower than anticipated.

"Fourth-quarter revenue reflects lower than anticipated sales of its capture devices due to slower than expected sell through at retailers, particularly in the first half of the quarter," the company said.

GoPro shares had been halted for news pending after the closing bell and fell by as much as 24% after trading resumed. Google Shares of Ambarella, a major supplier of chips in GoPro cameras, were down about 9% in premarket trading on Thursday.

GoPro's performance in the fourth quarter was also affected by the unspectacular launch of its compact Hero4 model. Analysts at Morgan Stanley cut their price target on the stock in October and essentially described the launch as a flop after the company slashed the product's price not long after it was released.

Several analysts have expressed concern about the potential for GoPro's point-of-view cameras to gain mass appeal beyond the core group of extreme-sports enthusiasts.

GoPro said it would incur a $21 million charge related to further price changes to the Hero4 in December.

The layoffs, which follow a headcount-growth pace of about 50% in the past two years, will cost GoPro $5 million to $10 million. Much of this will be severance costs, according to the company.