This lens ok?

[jdowning 0]

Hi there

 

I will be installing a Dahua IPC-HF3500 camera and I was wondering if this lens would be compatible? If not, would it still work but what would the disadvantages be?

 

http://www.dahuasecurity.com/products/ipc-hf3500--4.html

http://www.sourcesecurity.com/technical-details/cctv/image-capture/lenses/tamron-m12vg412.html

 

 

Many thanks in advance

 

Jack

[Q2U 0]

You've probably forgotten more then I will ever know bro...but isn't that a manual lens for a camera that supports an electronic lens? Or am I missing something.

[MaxIcon 0]

It's compatible, but not optimal. Here are the issues:

 

- The HFW3500 has auto-iris, and the lens is manual iris. It'll work on the camera, but you lose the auto-iris advantages, which are mostly getting sharper pics in bright light with better depth of field due to the iris closing down, as well as giving you a broader range of lighting flexibility. Still, this isn't a big deal, and many people run this way.

 

- The HFW3500 has a 1/2.5" sensor, and that lens is for a 1/2" sensor. The good thing is that the center is generally better quality than the edges of a lens, so you'll get improved image quality. The downside is that you'll only be capturing part of the image, so you won't get the full benefit of the 1.4 f-stop, and your focal length will be equivalently longer than the same focal length in a 1/3" lens.

 

That is, at 4mm on this lens, your sensor will only capture the middle part of the image, so will act more like a 6mm lens (for example). Figuring out the exact scaling factor depends on the actual dimensions of your sensor.

 

- The HFW3500 can use a C or CS mount lens, and this is a C mount lens. It'll work, but you'll need a CS mount adapter, which adds some length so it'll focus on the sensor correctly:

http://en.wikipedia.org/wiki/C_mount

 

Ideally, a good quality 1/3" auto-iris lens of the appropriate length will do the job. The good news is that these are easier to find and less expensive than 1/2" lenses, though picking the right one can be tricky. Good brands are Fujinon, Computar, CBC, and others.

 

You'll also want an IR corrected lens if you'll be using IR illumination, and a 5MP rated lens to get the best quality. If you go to ebay and search on mpir, you'll see some reasonably priced lenses, though I don't think they're 5MP - you'd have to check the vendor's specs to see for sure.

[Q2U 0]

...Here are the issues...

 

Wow. What a great post. Thank you. " title="Applause" />

[MaxIcon 0]

Been down that road, bought the wrong lens more than once, and I still do it now and again. Happy to help!

[jdowning 0]

It's compatible, but not optimal. Here are the issues:

 

- The HFW3500 has auto-iris, and the lens is manual iris. It'll work on the camera, but you lose the auto-iris advantages, which are mostly getting sharper pics in bright light with better depth of field due to the iris closing down, as well as giving you a broader range of lighting flexibility. Still, this isn't a big deal, and many people run this way.

 

- The HFW3500 has a 1/2.5" sensor, and that lens is for a 1/2" sensor. The good thing is that the center is generally better quality than the edges of a lens, so you'll get improved image quality. The downside is that you'll only be capturing part of the image, so you won't get the full benefit of the 1.4 f-stop, and your focal length will be equivalently longer than the same focal length in a 1/3" lens.

 

That is, at 4mm on this lens, your sensor will only capture the middle part of the image, so will act more like a 6mm lens (for example). Figuring out the exact scaling factor depends on the actual dimensions of your sensor.

 

- The HFW3500 can use a C or CS mount lens, and this is a C mount lens. It'll work, but you'll need a CS mount adapter, which adds some length so it'll focus on the sensor correctly:

http://en.wikipedia.org/wiki/C_mount

 

Ideally, a good quality 1/3" auto-iris lens of the appropriate length will do the job. The good news is that these are easier to find and less expensive than 1/2" lenses, though picking the right one can be tricky. Good brands are Fujinon, Computar, CBC, and others.

 

You'll also want an IR corrected lens if you'll be using IR illumination, and a 5MP rated lens to get the best quality. If you go to ebay and search on mpir, you'll see some reasonably priced lenses, though I don't think they're 5MP - you'd have to check the vendor's specs to see for sure.

 

You know your stuff - thank you so much for taking the time to reply. I really appreciate it.

 

I noticed you said the HFW3500 - is this the same as the HF3500? Also, I noticed on the spec page for this particular lens that it says that it is 'Auto Iris'. Do I still need a CS adapter even though the camera supports it?

 

Many thanks for your help again.

[tomcctv 187]

Hi. yes the tamron will fit direct to your dahua ... and the lens you listed is auto iris.

 

 

tamron are one of the best around ...... you can buy direct there in the US and UK

[jdowning 0]

Hi. yes the tamron will fit direct to your dahua ... and the lens you listed is auto iris.

 

 

tamron are one of the best around ...... you can buy direct there in the US and UK

 

Hi Tom, but maxicon says otherwise? Would a 1/2.8" be a lot different over a 1/3 lens?

 

What about adapters and such? Many thanks

[MaxIcon 0]

Sorry, Tom's right - the spec says auto-iris. The picture is manual iris - you can see 3 manual adjustments - so that's not the actual lens they have listed.

 

It looks like that site has their pictures crossed up, as this one is an auto-iris lens (the bump on the base is the motor), and is described as manual iris:

 

I was on autopilot on the HFW bit, due to typing HFW3300 a lot.

 

1/2.8 is about the same as 1/3. You can mount a CS lens directly to the camera, but will need an adapter to mount a C lens, like this:

http://www.ebay.com/itm/5mm-CCTV-Camera-C-CS-C-CS-mount-Lens-Adapter-Ring-Extension-Tube-/251070787493?pt=US_Filter_Rings_Holders&hash=item3a74fc2fa5

 

You can't go the other way - CS mount lens on a C mount camera.

Edited April 12, 2013 by Guest

[ssmith10pn 0]

Hi. yes the tamron will fit direct to your dahua ... and the lens you listed is auto iris.

 

 

tamron are one of the best around ...... you can buy direct there in the US and UK

 

I have to respectfully disagree.

We have had an awful time getting good pictures on Avigilon 5MP box and dome cameras. The focus is so touchy you can never really nail the focus.

 

Fujinon on the other hand is much better. The Fujinon DV3.4x3.8SA-SA1 is an awesome lens with good feel on the focus mechanism but it is a C mount though.

It seems like the IR cut filters hurt daytime image quality on the higher megapixel cameras.

[jdowning 0]

Sorry, Tom's right - the spec says auto-iris. The picture is manual iris - you can see 3 manual adjustments - so that's not the actual lens they have listed.

 

It looks like that site has their pictures crossed up, as this one is an auto-iris lens (the bump on the base is the motor), and is described as manual iris:

 

I was on autopilot on the HFW bit, due to typing HFW3300 a lot.

 

1/2.8 is about the same as 1/3. You can mount a CS lens directly to the camera, but will need an adapter to mount a C lens, like this:

http://www.ebay.com/itm/5mm-CCTV-Camera-C-CS-C-CS-mount-Lens-Adapter-Ring-Extension-Tube-/251070787493?pt=US_Filter_Rings_Holders&hash=item3a74fc2fa5

 

You can't go the other way - CS mount lens on a C mount camera.

 

Hello MaxIcon, many thanks for your reply and to the others that have replied here.

 

On the Dahua website, it says the following 'Lens Type C/CS' - correct me if I'm wrong, but does that not mean it can do both?

Also - with the lens that I mentioned, would night time images be any good? Of course I'd have a bit of small light, but I heard CMOS cameras are typically worse than CCD cameras?

 

Thanks again

 

Jack

[MaxIcon 0]

C/CS means that it's a C mount lens, and can work on a CS mount body with an adapter. C mount cams mount the lens further out (they call this the flange back length), so to get the focal point onto the sensor, you need an adapter to move it out a little for the CS body. It's a physical difference, and the lens may come with an adapter, since CS mount is what most cameras take these days. I've bought a few lenses with CS adapters already installed.

http://www.vision-doctor.co.uk/optical-basics/lens-mount-and-flange-back.html

 

This is a reasonably fast f1.4 lens, but not super fast. The smaller the number, the more light it lets in. The image will be for a 1/2" sensor, so some of that light will miss your 1/2.5' sensor, making it the equivalent of a slower lens. 1/2" sensors with fast 1/2" lenses give the best low light performance in general, as you've got a large sensor, with larger pixels, with more light hitting the sensor. These systems tend to be more expensive, though. There are some 2/3" and 1" systems out there, but these tend to be special purpose systems.

 

Generally, a fast lens is F1.2 or below. Faster lenses can cause difficult focusing, similar to what ssmith10pn mentioned, as the depth of field gets smaller as the f-stop gets smaller. Like everything in optics, there are trade-offs.

 

The lens is only one part of the night performance, and Dahua, in general, doesn't have great performance in terms of their sensors and processing. I don't know about this camera, but the only way to tell for sure is to give it a try. If there are demo videos posted somewhere, that will help too.

 

I got confused over the sensor size; it's 1/2.5", or approx 0.4" diagonal. 1/3 is 0.33" diagonal, 1/3" is 0.5" diagonal, so a 1/3" lens may not work well on this cam, giving dark corners. A 1/2" lens will definitely do the trick; a 1/3" lens may or may not, and a 1/2.7" lens like this one (http://computarganz.com/file.cfm?id=620) is right on the edge. Check the PDF for this Computar lens for some illustrations of sensor size issues.

 

Sensor and lens size descriptions are a holdover from an earlier day of glass tube encased sensors, so it's hard to say exactly what the compatibility is without knowing the actual sensor dimensions. This is complicated by the change from 4:3 sensors to 16:9 sensors, so it's a bit of a jungle out there.

 

I don't really follow the CCD vs CMOS differences, but these are pretty well documented on the web.

[ssmith10pn 0]

Good info Max!

[blakem 0]

Hi I had a similar question. I am trying to get one of the new Hikvision box cameras DS-2CD2820F, but the sensor size is 1/2.8"(0.357"). Being just over 1/3" I am not sure if a 1/3" CS lens will fit without vignetting. It is only about a 7% difference in size so it doesn't seem like much. I personally think I will be ok, but I was wondering what others with some experience think.

 

I was looking to get a Fujinon 3 MP Varifocal Lens (15-50mm, 3.3x Zoom) YV3.3X15SA-2 which is a 1/3" CS lens. Hoping to use this setup to capture a mid to tight shot of a public speaker indoors at a podium with quality good enough to post to youtube.

 

So will the slightly larger than 1/3" image sensor give me trouble with a 1/3" lens?

[MaxIcon 0]

 

This should be good. Most lenses have image circles a fair bit larger than the sensor they're rated for, and 1/2.8 sensor cams tend to use 1/3" lenses in general.

 

I tried to test some 1/3" M12 lenses on a 1/2" sensor cam to measure the image circle, but it was just too big, and I only had vignetting on one side of the sensor.

 

You won't know for sure until you try, but I'd guess you won't see a problem.

 

[blakem 0]

This should be good. Most lenses have image circles a fair bit larger than the sensor they're rated for, and 1/2.8 sensor cams tend to use 1/3" lenses in general.

 

I tried to test some 1/3" M12 lenses on a 1/2" sensor cam to measure the image circle, but it was just too big, and I only had vignetting on one side of the sensor.

 

You won't know for sure until you try, but I'd guess you won't see a problem.

Thank you maxicon. I thought there would be a little extra designed into it. Probably the quality outside of the designed image circle loses quality but I don't think i will notice for my purposes. I think i will give that lens a shot once i can get a hold of the camera.

[LorenzoS 0]

http://www.fujifilm.com/products/optical_devices/cctv/security/#megapixelvarifocal