Dahua camera lens options

[msecure 0]

Open up the IPC-HFW2100 but quite difficult to remove the lens to change it even though I don't see any screws locking the lens into position.

.

[testshoot 0]

Open up the IPC-HFW2100 but quite difficult to remove the lens to change it even though I don't see any screws locking the lens into position.

.

 

If you will notice, there is a lock ring that screws down to the base to lock it into position after you screw it in and out to find the focus. It is a knurled ring right above the base, below the exposed threads.

 

I did hear back from the Ragecams guy saying he might have some lenses but didn't elaborate other than to say 12mm was a narrow view. I am surprised he commented on that as you would think I would have known that and wanted that?

[testshoot 0]

Open up the IPC-HFW2100 but quite difficult to remove the lens to change it even though I don't see any screws locking the lens into position.

[

 

Just noticed your lens is marked 3.6mm EGA. I am guessing EGA is a brand vs. the Mega brand on the 6mm lens in the Q-See version. Since you apparently didn't change the lens (yet), I am guessing you ordered it as a 3.6mm? 3.6mm is one of the two lenses I bought for my cameras and it focused, unliked the 12mm which couldn't screw in enough. The Mega brand 3.6 screws in almost exactly the same distance as the 6mm. I am assuming the 8mm is almost the same distance as it is the other of the three offered by Dahua.

[mroek 0]

It does say MEGA, it's just that the letter M is masked by the camera flash highlight.

[testshoot 0]

You might want to try ragecams on ebay. They have quite a range of gear, claim to offer good service, and I had good luck with a lens I bought from them. Shoot them an email and see if they have any good advice.

 

The guy wanted $89.00 for the lens...he is crazy. I saw his prices for the GoPro lenses and already thought his pricing was high. They guy is making a huge profit on these lenses. The MEGA lens which is of good quality (glass lens, metal body) goes for $14 and BikeRider got a set of 4 or 5 lenses for $15...although I am guessing they were plastic.

 

Thanks anyway, but I am not desperate enough to pay that much for a lens, even if it was platinum plated.

[MaxIcon 0]

This is the basic problem with buying Chinese lenses. You can't really tell by looking if they're the same or not, though you can guess in some cases. I haven't seen the lenses you're referring to, so I can't say. Once you have them in hand, it can be easier, but that's a gamble, especially if they're expensive.

 

FWIW, I doubt MEGA is a brand name, any more than IR is, but I could be wrong.

 

If you go to CS mount lenses, you can buy $25 lenses that appear to have the same specs as a $300 Fujinon. It's easy to tell the difference, due to branding, and it's obvious when you mount them, but board cam lenses don't seem to have branding, or even labeling in many cases.

 

So, one basic law of optics applies - if it's cheap and new, it's probably not high quality. I don't think the Chinese have managed to overcome that. Unfortunately for the buyer, too cheap generally means mediocre quality, but expensive doesn't mean high quality, as some people mark DX lenses up and re-sell them for much more. Maybe RageCams is doing that - hard to say without actually comparing them.

 

http://www.m12lenses.com is the in-between alternative; hopefully better quality than DX, while cheaper than Rage. If they don't have what you need, you're probably out of luck without spending more money.

 

If you want a reference point, try pricing lenses from some of the big boys who use M12 lenses on their MP cams - Axis, Mobotix, etc. You can probably assume these are better quality than the no-name Chinese lenses, though they may well be made in the same factory.

[testshoot 0]

M12lenses.com sells what appear to be two grades. One line is simply called "board lenses" with no brand name. The 12mm lens is f2.0 and sells for$5.27.

 

They also sell a "Mega Pixel" brand that is labeled MEGA, the same labeling as the Dahua provided lens. The MEGA 12mm lens is F1.8 and marked IR and sells for $14.70.

 

The cheaper lens also appears to have a plastic body vs. metal.

 

Bikerider was able to buy a set of 4 or 5 lenses for the same price as I paid for one MEGA lens. He was able to get the 12mm and 16mm to work, as apparently their BFL was appropriate for the Dahua camera.

 

I am unable to find the BFL spec for the MEGA brand of lenses, or any other brand for that matter so I can know without buying whether they will even focus, never the less the quality of the lenses.

 

I am in contact with another company, Peau, that only sells plastic body lenses and is asking what the BFL should be, and I can't even tell them.

 

I just didn't think this would be so tough given we are working with a standard M12 lens.

 

I did check the Atrix brand but it seems the don't offer a 12mm lens.

 

Mobotix says they glue their lenses in place and want 200 Euro to swap the lens. They don't appear to sell the lenses themselves individually for those who want to attempt the replacement.

 

I checked the specs on the Mobotix site and they give no information on the BFL for their M12 line.

 

It would seem there is a potential market for people like myself who would like to buy a quality lens and swap them. I can't believe everyone is happy with the Q-See 6mm only option, especially given that Dahua at least offers the 3.6 and 8mm options.

 

I contacted Cherry who has been mentioned as a good source for Dahua and she didn't know if there was a 12mm option that worked or that she could sell.

 

If nothing else materializes, I might buy the Mega 8mm option and settle for the wider than desired width.

 

Thanks

[buellwinkle 0]

Mobotix is a little different in that they sell the lens and sensor together as one expensive unit. The Mobotix M12 lenses are glued in place, but their domes have interchangeable lenses. I believe the new M15 (replacement for the M12) will have interchangable lenses from the S14. Of course if you can afford a $1,500, why mess with Dahua

 

Bikerider I believe used 12mm and 16mm lenses from dx.com, pretty cheap, only major downside is it will take a while to get. Maybe you can buy one of the lenses from Bikerider that he's not using.

[testshoot 0]

Hello,

 

I think the 16mm would be too narrow and I think he had chromatic aberration on the 12mm or it wasn't IR compatible. I checked the DX page and it doesn't mention IR for the lenses.

 

His sample show was in a cloudy condition and he mentioned fringing when the sun came out.

 

He also said the 6mm in the kit was lower quality than the 6mm that came with the camera indicating that the whole set of lenses is of lower quality that the Mega Pixel brand.

 

I am in email communication with the person from m12lenses. They are trying to help me find an appropriate 12mm lens. Since the Mega Pixel 12mm lens couldn't screw in far enough, they are suggesting that changing the mount might be the solution. Don't know what that will take. They asked for the length from the PCB to the top of the mount to see if they have a shorter mount that will let the 12mm lens screw in the 2-3mm more that it needs.

[MaxIcon 0]

They also sell a "Mega Pixel" brand that is labeled MEGA, the same labeling as the Dahua provided lens. The MEGA 12mm lens is F1.8 and marked IR and sells for $14.70.

 

Yeah, I have several of these lenses, bought from a variety of places, and some that came on cams. Again, I really doubt that "Mega Pixel" or Mega is a brand name.

 

I've got a fair bit of experience with Chinese optics outside the IP cam arena, and I'd guess there's a factory or three that stamp their lenses with this. Whether it's even true (MP rated, that is, and how many MP is that?) is not something I'd bet on without testing, and even then, I wouldn't apply the results to a lens bought from another vendor or manufactured in another lot.

 

Folks who have mid- to high-end optics gear manufactured in China will tell you that quality control and spec control require constant supervision of the manufacturing facility, and that you can't take anything for granted without verification. You're just not going to get that with these inexpensive lenses unless a vendor has jumped through the required QC hoops.

 

Seriously, even a $30 lens isn't something that would give me a warm, fuzzy feeling when it comes to quality control.

[dexterash 0]

You have a very good point.

 

As a general rule, optics are what make an image look good, right? (ask the photo people, they know that)

 

MEGA/MEGA PIXEL/ETC are not brands, are just some lens that are rated to work with "megapixel" cameras...

But megapixels cameras can be 1 to 10, let's say... So how do you know you bought an 1 or 10MP lens? (we, usually, exclude the IR filter, since that can be done at sensor level - thus making the lens changing easier)

 

You don't know, unless you test and confirm it (talking about China). Also, you don't know it if you have a lot of good MP lens or just 1/10 are MP and the rest are D1.

[testshoot 0]

Image quality is primarily the optic, the sensor, and the software that takes the raw data and makes it into an image. About all we can change on a camera is the lens.

 

I have to assume a lens that cost $15 is better than if you pay $14 for six of them. Also, as a general rule, lenses sold with a metal mount are better than ones sold with a plastic mount.

 

I am working with two vendors to find a good quality compatible 12mm lens. Rage's price of $89 is outrageous no matter how good it is and I am not desperate enough to pay as much for a lens as the whole camera, or nearly so.

[teknologs 0]

Samples part 2.

 

I'm not sure why the bottom of the 16mm image is dark. Might be cloud shadow, might be my finger over the lens. This might be the best lens in the set.

 

The 12mm isn't great. There is a lot of edge softness.

 

I don't have any samples of the 2.8mm because they do not fit correctly. I dn't have a comparable sample from the 3.6mm because it is installed in another camera. The 3.6 works well, but does have some port holing effect.

 

please send pay link...?

[gilligan 0]

Image quality is primarily the optic, the sensor, and the software that takes the raw data and makes it into an image. About all we can change on a camera is the lens.

 

I have to assume a lens that cost $15 is better than if you pay $14 for six of them. Also, as a general rule, lenses sold with a metal mount are better than ones sold with a plastic mount.

 

I am working with two vendors to find a good quality compatible 12mm lens. Rage's price of $89 is outrageous no matter how good it is and I am not desperate enough to pay as much for a lens as the whole camera, or nearly so.

 

I'm talking completely out of my arse here, but could you not cut down the lens by a few millimeters to allow it to then screw down far enough?

[mroek 0]

I'm talking completely out of my arse here, but could you not cut down the lens by a few millimeters to allow it to then screw down far enough?

That's not possible. The rear lens element is located, you guessed it, at the rear. Cutting would just render the lens unuseable.

[gilligan 0]

I gotcha... yep, talking out of my arse as usual.

 

I've just been reading this thread with much interest because I'm probably gonna pick up some dahua cameras soon and I really like the 1.3MP mini bullet for some internal applications but would rather a 2.8 or less lens for my application.

 

Hoping these will just slip right on with out much fuss.

[mroek 0]

I wrote a separate post about lens(es) bought from Anykeeper:

 

viewtopic.php?f=19&t=34667

 

I bought several lenses, but I have only tested the 3.6 mm version, which fitted without issues, and which actually had quite a bit wider view than the factory installed 3.6 mm lens.

[testshoot 0]

I'm talking completely out of my arse here, but could you not cut down the lens by a few millimeters to allow it to then screw down far enough?

That's not possible. The rear lens element is located, you guessed it, at the rear. Cutting would just render the lens unuseable.

 

Actually, on the lenses I tested the rear lens was not all the way at the back of the threads. One each of the lenses I am guessing there was about 2.5mm space from the last element to the end of the threads. I am guessing on the lenses where I wasn't able to screw the lens in far enough that I could have either cut down the lens mount or cut some threads off of the back of the lens, depending on where the obstruction was.

 

One supplier did suggest buying a shorter lens mount which would be the same as cutting some threads off of the lens mount if you were talented enough to do that without messing things up.

 

I haven't been able to get a BFL spec from Dahua and some of the lens suppliers won't give or don't have a BFL spec for their lenses so it is a bit of a crap shoot.