PowerShot sx720 hs -- When I zoom, why does range at top of screen go up to 160X, not just 40X?

[rogsanjco]

Having just bought this camera, partly because of its zoom capacity, I was surprised to see the range shown on the screen not stop at 40X but continue to 160X. I just took photos of trees in the distance at 40X, 80X and 160X, and they seemed to be equally clear. This can't be, right? What understanding am I missing? Also, is there any consensus re murkiness of image as the camera goes beyond 30X toward 40X?

[John_]

You have the digital zoom of 4X which is kicking in after you reach the max optical zoom of 40X. You can turn off the digital zoom in settings if you choose to. The zoom bar should change colors when it goes from optical to digital zoom too so you'll know when you've crossed that line.

I use a tripod for any serious shot at long zoom when I can but I don't see any noticable image deterrioration although there probably is some. I have the SX50HS, simalar to yours except mine has 50X optical zoom and then the 4X digital zoom

[rogsanjco]

John, thanks for your helpful response. I looked up the difference between optical and digital zoom and don't see any reason to use the latter. I'm curious why Canon includes a feature that only crops and enlarges, with poorer quality, a section of an image taken at the camera's highest optical zoom when the user in fact has the option to simply crop the highest optical zoom image with better image clarity. Must be some reason(s) for some people. ??? Can someone shed light on this question?

[kvbarkley]

So you can see what you are getting when you take the picture. To advertise a higher zoom rate?

It is probably the USP:

http://theonlinephotographer.typepad.com/the_online_photographer/2016/07/beyond-the-usp.html

[rogsanjco]

Thanks for our helpful response. I get the UPS angle. I'm sure that's often the case. To experiment, I just did a shoot of my water cascade. First shot with no zoom showed entire cascade in its landscaped setting; second at 40X showed a few different colored stones over which sunlit water was flowing; third at 80 showing closer up of just a few rocks under the flowing water; and fourth at 160 showing just one stone probably more blured by the extreme digital zoom than by the water flowing over it. Although it wasn't conclusive re whether what I got at 80 is what I would get when cropping 40X to the same closer-in image in 80, for what it's worth, the 80 image looked good, while 160 probably is too murky. I will keep an open mind about going somewhat closer than the 40X (at least to 80), but maybe not all the way to 160. 

[kvbarkley]

I always just turned off the digital zoom. It is usually an option.

[rogsanjco · Accepted solution]

Because, in my trial, I seemed to get good resolution of images closer up than at the limit of my 40K optical zoom, I will leave the digital zoom on and see how much use I get from it. 

[samintx]

A revelation! I had no idea the zoom went up so far and that I probably should have turned it off for better pictures. I'm going to check my other Canon's. Thanks for tip.