Fixed vs Vari-Focal Lenses

B

bigeye

n3wb
Feb 15, 2019
22
1
UK
Hi,
In mulling camera options I've been focusing more on vari-focal cameras. However, I have a question; are there situations where fixed is the better bet? Or is it simply budget that dictates whether to go down the fixed route?

Regards,
Dave
 
I would vote budget.

I bought a vari-focal because the guide said it was recommended.

Originally I thought it be fully zoomed out all the time so I thought about just getting a fixed camera but I thought if someone went through all that effort to make a guide, it best to learn from someone else’s mistakes.

Within a month of playing around with the camera and watching the recordings I found that during the day it’s nicer to have it fully zoomed in as you can really see and identify who is coming in your yard. At night I like it zoomed out so I can get an overall picture of the night time happenings.

All that said in my opinion it’s nice to have the flexibility and the extra cost is not a deal breaker. Worst case, if you found that you always leave it on one zoom setting and never change, the next time you buy a camera (and there will be a next time) just buy a fixed camera for that location and take the vari-focal to the new location.
 
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start with a vari-focal. you'll eventually settle on the best 'view' for that cam location (eg, maybe 6mm is best there.) then you can replace it with a fixed (cheaper) unit with the desired lens, moving the VF to your next location for tuning there...
 
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It’s mostly budget. I prefer varifocal, but if I was on a budget and had to shave $50 off of each camera I’d go with 6mm lenses in most exterior applications and 2.8 or 3.6mm at the front door.
 
If a built-in mic isn’t required, Dahua’s 2231 Starlight varifocal turret was only about $10 more than the 4231 fixed-lens Starlight turret at one point...
 
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archedraft said:
I would vote budget.

I bought a vari-focal because the guide said it was recommended.

Originally I thought it be fully zoomed out all the time so I thought about just getting a fixed camera but I thought if someone went through all that effort to make a guide, it best to learn from someone else’s mistakes.

Within a month of playing around with the camera and watching the recordings I found that during the day it’s nicer to have it fully zoomed in as you can really see and identify who is coming in your yard. At night I like it zoomed out so I can get an overall picture of the night time happenings.

All that said in my opinion it’s nice to have the flexibility and the extra cost is not a deal breaker. Worst case, if you found that you always leave it on one zoom setting and never change, the next time you buy a camera (and there will be a next time) just buy a fixed camera for that location and take the vari-focal to the new location.
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This is NOT what they were designed for, to be zoomed in and out on an on going basis. It was designed to set it up at time of installation and tweak the FOV, then leave it alone.
You want to see who did it, not just what happened....even at night.
 
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looney2ns said:
This is NOT what they were designed for, to be zoomed in and out on an on going basis. It was designed to set it up at time of installation and tweak the FOV, then leave it alone.
You want to see who did it, not just what happened....even at night.
Click to expand...

Hmm so I guess I took the sunrise and sunset program a little too far than. I am assuming you are suggesting that zooming in and out once a day will wear out the camera faster?

FWIW, I am able to clearly identify people at night assuming they get closer to my house (the driveway is 75’ long). During the day it is nice zoomed because you can clearly see the people around the street area as they typically do not come up to the house. If they do during the day, I have other cameras around the house.
 
pozzello said:
start with a vari-focal. you'll eventually settle on the best 'view' for that cam location (eg, maybe 6mm is best there.) then you can replace it with a fixed (cheaper) unit with the desired lens, moving the VF to your next location for tuning there...
Click to expand...

That's what I did. The varifocal was my first camera and was used to test various locations and focal lengths. I eventually deployed it in a location where I needed a focal length between the 3.6 mm and 6 mm available on the fixed lens models.

My final tally ended up being 3 x 2.8mm, 4 x 3.6mm, 1 x 6mm, and 1 x ~4mm. The varifocal saved me a lot of guessing.
 
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archedraft said:
I would vote budget.

I bought a vari-focal because the guide said it was recommended.

Originally I thought it be fully zoomed out all the time so I thought about just getting a fixed camera but I thought if someone went through all that effort to make a guide, it best to learn from someone else’s mistakes.

Within a month of playing around with the camera and watching the recordings I found that during the day it’s nicer to have it fully zoomed in as you can really see and identify who is coming in your yard. At night I like it zoomed out so I can get an overall picture of the night time happenings.

All that said in my opinion it’s nice to have the flexibility and the extra cost is not a deal breaker. Worst case, if you found that you always leave it on one zoom setting and never change, the next time you buy a camera (and there will be a next time) just buy a fixed camera for that location and take the vari-focal to the new location.
Click to expand...
Honestly I've not seen any specs that says you definitely should not use the focus regularly but as stated by others, that's not the intended purpose of a varifocal camera. Typically the problem you would have though is a matter of being able to zoom in on exactly what you want. Since there is no pan\tilt, a zoomed out overview of a street may get you a zoomed in view of a rock or nothing specific and would still require manual adjustment. If you just had to use it to zoom in\out daily you would need to position in zoomed in on what you want to see then be able to accept whatever FOV you are left with when zoomed out. It is not optimal by any means but I don't see why you could not do it.
 
nbstl68 said:
Honestly I've not seen any specs that says you definitely should not use the focus regularly
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Same here. I think some of the "it's not meant to change the zoom regularly" came when the 5231 varifocal turret first came out and some folks were trying to use as a cheap PTZ and were complaining about how long it can take to refocus after a zoom.
 
I think another big reason to set a varifocal at one focal length and leave it is that each time you zoom or reposition you need to rework your motion detection settings (and possibly other settings). Being able to see an overview of what's happening in your yard and being able to identify strangers at a distance are two separate user requirements that could be served with a single varifocal camera and a lot of fiddling around, but would be much better served with two cameras.
 
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May be why that double boobie cam seems to be popular...cover two areas w a small footprint...but everyone poo-poos the whole dome thing for outside. My bro-in-law has some Panasonic dome cams on all sides of his house for over 10 yrs now and only a couple of them are starting to get foggy.
 
nbstl68 said:
May be why that double boobie cam seems to be popular...cover two areas w a small footprint...but everyone poo-poos the whole dome thing for outside. My bro-in-law has some Panasonic dome cams on all sides of his house for over 10 yrs now and only a couple of them are starting to get foggy.
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The bigger issue is direct rain when you have IR on. I posted a sample in the thread for that camera. If you live in a rainy climate AND can't keep it dry AND need the onboard IR, then I wouldn't recommend it. I'm not too concerned about the dome fogging. If it happens in 5-10 years, I'll just buy a 16k starlight to replace it.
 
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