2.8mm or 4mm lens? (Photo added with 4mm lens, is 2.8mm is better for me?)

[Cossie]

I have connection problems with 2032, I was planning to upgrade 8MP, now it's time. I want to buy 2085

I have this field of view with 3MP 2032 with 4mm lens:



As you can see I can't record the first line of cars. Is 2.8mm lens is better for me? Licence plate readability is OK with 4mm and 3MP. Is 2.8mm and 8MP is better or worse for licence plate readability from this view?

 

[mlapaglia]

Are there lights on this location at night? What are your goals with the camera?

 

[Cossie]

Are there lights on this location at night? What are your goals with the camera?

Night lighting is like this:


My goal is knowing the what happened, getting the best licence plate readability for the money. One day my neighbour said he could not find the keys for the home. We looked at the records. He had forgotten the keys on the trunk of his car and he drove the car. We was able to see it from records. Now I want more detail and more field of view.

 

[cyberwolf_uk]

To be honest I think there may be a lot of wasted pixel area you don't need to cover (highlighted in red) and some area do you really need? (highlighted in green)
Would it make sense to lower you cameras slightly to achieve better face ID's / number plates and add more cameras cover the areas with the cars say 3 x 6mm or 12mm cameras covering cars and workers and one 3.6mm for overhaul view?

 

[Cossie]

To be honest I think there may be a lot of wasted pixel area you don't need to cover (highlighted in red) and some area do you really need? (highlighted in green)
Would it make sense to lower you cameras slightly to achieve better face ID's / number plates and add more cameras cover the areas with the cars say 3 x 6mm or 12mm cameras covering cars and workers and one 3.6mm for overhaul view?

View attachment 21977

Yes it's an old snapshot and it wasn't my adjustment. Electrician man was adjusting it according to my instructions. He endangered himself. I scared from the height and I said him it's OK. Now I learned how to remove the glass of the window. I reach the camera safe and easily now. I tried another adjustments but it still hasn't enough field of view.



So my question is which has more detail for licence plates? 2.8mm - 8MP or 4mm - 3MP ? Or are they equal? If I buy 2.8mm - 8MP, field of view is an upgrade for sure but how about the details?

 

[adamg]

You definitely want a wider field of view. The cameras you are looking at should list their field of views in the specifications. And if you don't see enough resolution for reading license plates on a wider field of view, then add a second camera that is zoomed it at a bottleneck point where the cars have to pass to enter/exit the area.

 

[bp2008]

8MP with 2.8mm should be better pixel density than 2-3MP with 4mm.

I'd get 2.8mm and use it for the overview.

I would not rely on an overview camera to read license plates. Put narrower lens cameras (6mm+) at the choke points where all vehicles much pass to get in and out of the parking lot. Limit their exposure time to 1/500th or 1/1000th second so they can get a clear plate reading at night.

 

[Ookie]

This is correct. You are playing with fire trying to get plates with your current 4mm. You may be able to get them from some angles in good lighting conditions. But absent that, your reliability is suspect now. Go to 2.8 and you are going to be hosed.

If you want to do it right, take bp2008's suggestion and set up a specific cam at a choke point to get plates.

2.8 4K overwatch would be great. My only question is the lens quality (e.g. clarity of the glass)--will everything get through to the sensor. I'm not sure with Chinese glass. Also, keep an eye on storage--you are going to eat it up really quick at 4K.

 

[Cossie]

I bought 2.8mm 2085 from aliexpress, after 10 days he said no 2.8mm in the stock. Can I change the lens?

 

[bp2008]

Unfortunately that isn't very surprising, this guy wasting your time like that. That is why people on this forum cling to the good sellers they find.

Technically you can change the lens on most cameras, however it isn't always simple and straightforward. Some lenses have poor optical clarity and are blurry in some spots and sharp in others. Some lenses are too long or too short and won't fit in the camera or can't be focused properly. Some lenses might focus well during the day but be blurry at night with infrared.

Consider a varifocal 4K model if you can't find one with the right fixed lens. Many basic varifocals are 2.8mm at their widest setting, and another benefit is that varifocal lenses usually bring in more light due to being physically larger, and that makes night vision better.

 

[Cossie]

Unfortunately that isn't very surprising, this guy wasting your time like that. That is why people on this forum cling to the good sellers they find.

He entered a tracking number 4 days ago, but he asked for 4mm 2 days ago. Is it normal?

 

[Tolting Colt Acres]

Just because he entered a tracking number doesn't mean he's sent anything. All it means is he generated a label. I've had sellers waste my time like this as well, they do it to get around the AliExpress processing time requirement.

 

[Cossie]

I ordered at Sept. 28. 4 days after I asked "Is everything OK?". After a day with no reply, I tried to cancel the order. He rejected and said it's a national holiday. I said "OK ship it after holiday". This is the full message history:



Now the tracking number he entered blocks me for canceling the order.

 

[RBW]

Who’s the seller?

 

[Cossie]

Who’s the seller?

A Plus Electronics Ltd. - Small Orders Online Store, Hot Selling and more on Aliexpress.com | Alibaba Group

 

[Cossie]

4mm 2085 is arrived. It's not showing up in the network. Also red leds doesn't turning off. The 12v/1A adapter is not enough I think? It says use a 12v/2A-5A adapter on the Quick User Guide.

 

[Cossie]

Still not the best field of view but much more detail

 

[bp2008]

I like the picture, but I agree it would be a more satisfying overview if it had a wider lens.

 

[Cossie]

Do you recommend IR on or off?

Also what decoding do you recommend? H264 - H265 - H265+

H265 is selected now.

 

[mat200]

I bought 2.8mm 2085 from aliexpress, after 10 days he said no 2.8mm in the stock. Can I change the lens?

Hi Cossie,

Sounds like you should be looking at 2 cameras.

Here is a great example of changing lens on a 4K fixed lens dahua camera:
FYI - Some local Costco B&M have a Lorex / Dahua OEM 4K 6x camera kit and 8 port NVR for $800