What is the difference between a PTZ and a motorized varifocal?

[NightLight]

This is my first post, so hope this is the right place to post.

I am looking to get a camera. And I noticed some are PTZ and some are motorized Varifocal, which seems like the same thing. How are they different and what can one do that the other can't?

 

[Mr_D]

PTZ is meant to pan, tilt, and zoom all the time to track a subject.

Motorized varifocal cameras are meant to have their focal length fine-tuned during installation, then left that way.

 

[gwminor48]

A varifocal is nice because you can adjust it for the ideal focal length for your particular situation. Usually you set it for the best view and leave it there and it only zooms, doesn't move physically. PTZ zooms in and out and moves sideways, up and down so it is good in situation where you want to change your point of view.

 

[gwminor48]

@Mr_D beat me, I type too slow.

 

[NightLight]

So motorized varifocal can remotely zoom, but not pan and tilt? And of course PTZ can pan, tilt, and zoom remotely. Would you want to set a focal length for the motorized varifocal, and not zoom later? or is it OK to zoom later, just not as usefull since you can only zoom into the center of the image area?

And PTZ can automatically follow motion, like a person? Can the PTZ zoom in automatically as well? This is neat stuff.

 

[mat200]

So motorized varifocal can remotely zoom, but not pan and tilt? And of course PTZ can pan, tilt, and zoom remotely. Would you want to set a focal length for the motorized varifocal, and not zoom later? or is it OK to zoom later, just not as usefull since you can only zoom into the center of the image area?

And PTZ can automatically follow motion, like a person? Can the PTZ zoom in automatically as well? This is neat stuff.

Welcome NightLight,

Definitely check out the notes which Giomania has assembled:
IPCamTalk WiKi | IP Cam Talk

A varifocal purpose is to customize the FOV you need. They're not intended to zoom in and zoom in high frequency.

A PTZ is designed to PTZ frequently, and thus the hardware better supports those functions.

Automatically follow a person - more expensive PTZs have those options, in general the consensus here is the auto follow tech in the PTZ models we can afford is not as good as we'd like.

 

[Mr_D]

So motorized varifocal can remotely zoom, but not pan and tilt? And of course PTZ can pan, tilt, and zoom remotely. Would you want to set a focal length for the motorized varifocal, and not zoom later? or is it OK to zoom later, just not as usefull since you can only zoom into the center of the image area?

And PTZ can automatically follow motion, like a person? Can the PTZ zoom in automatically as well? This is neat stuff.

Yes, a PTZ can track motion and zoom in on it. This is automated as it would be impractical to sit at home all day doing it manually.

I have one Dahua varifocal camera. Its has allowed me to determine what focal lengths I need in what locations. With that information, I can purchase the correct fixed focal length camera for less money. For example, the Dahua 5231 starlight varifocal has a range of 2.7-12mm while the fixed models come in 2.8, 3.6, and 6mm versions. If you're really picky and need a 3.2mm focal length, the varifocal can do that. Also, if you need more than 6mm, the varifocal can handle that too. Yes, you can zoom them after installation, but there's little need to.

 

[NightLight]

Ah, I think I have it now. Thanks so much Mr_D, gwminor48, and mat200.

Is there a thread that covers how well the auto motion tracking works on various cameras? I am interesting in the Dahua Starlight PTZ cameras. Maybe I should start a new thread...

 

[mat200]

Ah, I think I have it now. Thanks so much Mr_D, gwminor48, and mat200.

Is there a thread that covers how well the auto motion tracking works on various cameras? I am interesting in the Dahua Starlight PTZ cameras. Maybe I should start a new thread...

HI Night

Look for some of the PTZ examples here, iirc Nayr had a few posted. You can search for his posts.

 

[NightLight]

I found some Nayr posts and videos. The auto tracking seems pretty impressive. I can tell it will be fun to play with.

Thanks and take care.

 

[Fastb]

Nightlight,

Welcome to the forum! And I see you've done some "search" here, to find answers to already-asked questions. Great! It's a fact of life that the typical newbie questions won't result in a big response from the experts, who get weary of answering the same newbie questions over-and-over. Plus, "Search" is faster than lobbing a question out there, and then, waiting for answers.

Nayr is extremely proficient, and can create a hack to improve performance of just about any technology. He's legendary. Considering nayr's skills, I advise you to carefully read his post about how he controlled the PTZ. His video of opening the gate, walking, and then leaving resulted in an awesome example of what a PTZ can do. (if that's the video you saw). A careful reading of his posts will reveal he used other methods to control the PTZ, such as a switch on the gate. The switch closure told his stawrberry pi or other Linux based widget to transmit specific PTZ commands to pant, tilt and zoom.

As nayr said, the auto-tracking available in reasonably priced really sucks. So nayr set about how to augment that, using other sensors and custom programming.

Bottom line: Don't believe the hype about PTZ auto-tracking. The technology for homeowners (at a reasonable price) is not like what you see on TV.

Again, welcome to the forum!

Fastb

 

[aristobrat]

And remember that not all Dahua PTZ models have auto-tracking, so that’s def something to verify before pulling the trigger!

 

[NightLight]

Thanks Fastb. The one I saw was someone ringing his door bell. But your point stand as he had to augment it with a doormat pressure sensor.

Good point aristobat. Seems the lower end Dahua's don't have auto tracking.

 

[nother newbie]

I found some Nayr posts and videos. The auto tracking seems pretty impressive. I can tell it will be fun to play with.

Thanks and take care.

Hello! I'm a newbie and just came across this forum. I'd like to know about Nayr's videos. Where can I find them?
Thanks!

 

[Fastb]

@nother newbie:
Welcome to the forum!

I'd like to know about Nayr's videos. Where can I find them?

1) Let Me Google That <--- I hope you can take a joke!
2) use the search feature on this website.
3) use google search, with a search term like: nayr, ptz, site:ipcamtalk.com. The "site" command restricts the search to his forum, and you'll get more hits for ipcamtalk threads.

 

[aristobrat]

Hello! I'm a newbie and just came across this forum. I'd like to know about Nayr's videos. Where can I find them?
Thanks!

Just a heads up that nayr dropped off the forum a good while so, so some of the videos are dated in the sense that newer/better spec’ed models may be available.

If you haven’t already found it, the Cliff Notes document has a bunch of good camera info from nayr and others in one spot.

 

[nother newbie]

Just a heads up that nayr dropped off the forum a good while so, so some of the videos are dated in the sense that newer/better spec’ed models may be available.

If you haven’t already found it, the Cliff Notes document has a bunch of good camera info from nayr and others in one spot.

Thanks! I'll check that out!

 

[nother newbie]

@nother newbie:
Welcome to the forum!


1) Let Me Google That <--- I hope you can take a joke!
2) use the search feature on this website.
3) use google search, with a search term like: nayr, ptz, site:ipcamtalk.com. The "site" command restricts the search to his forum, and you'll get more hits for ipcamtalk threads.

Thanks!! I think I tried to search buy couldn't come up with anything. I'll try again.