How to tell if a CS-mount lens is IR corrected?

[camera-newbie 0]

So, I've got one camera on it's way and it's got a 1/3" CS mount and I was looking at some Fujinon lenses but they don't apparently use the phrase "ir corrected" which I'm assuming I want for an outdoor camera for use in low-light situations (in this case the camera is the 1.3Mp Basler).. I was thinking, for example, of this one which has a decent focal range and has the needed DC iris this camera supports. Is the linked lens an IR corrected lens? Is their "ND filter" feature the give-away here? Please advise.. Thx!

 

Signed -- CS mounted lens newbie

[Soundy 1]

IR-corrected lenses will generally say, at the very least, "IR" right on them. Some also go as "day/night" lenses.

 

These are not required for low light... they ARE preferred for true day/night cameras (ie. those with movable IR cut filters).

 

If the camera doesn't state that it's TDN or ICR (or other similar acronym), then you don't need an IR lens.

[camera-newbie 0]

Thanks Matt.. This camera does have the removable cut filter.. so I'll see about finding a lens with IR correction.. I see pricing on these things is all over the map..

 

I did find this document on their site which does list which lenses are day/night so I'll stick with those if I buy a Fujinon lens.. Thx!

[camera-newbie 0]

Turns out there is no Fujinon that does what I want exactly so I looked over at Computar.. They've got two lenses that are both IR rated but one has an f1.3 aperture and the other is f1.8.. I'm thinking I ought to spring for the f1.3 since it will bring in more light.. Correct?

[Soundy 1]

Correct - almost twice as much.

[camera-newbie 0]

Thx! I might be buying multiples IF that other local guy sells me a few IQEye cameras since they have no lenses either..

[Soundy 1]

The 511 isn't TDN so you don't need an IR lens for it. You SHOULD try to get megapixel lenses for these, though - standard lenses will work, but you won't get the full quality possible with a megapixel cameras.

 

BTW, remember that the 511s don't have auro-iris controls, so those will need manual-iris lenses as well.

[Soundy 1]

Er, oops, you didn't say what models the IQs were...

[camera-newbie 0]

The iq's are the older (not current model) Sentinel's -- I'm specifically looking at the IQ853 -- unfortunately the specs don't really tell me everything I need to know about the lens -- I'm looking at the 1/2" varifocal IR lenses with CS mount -- unfortunately it does not specify what type of iris it needs -- DC, manual,etc..? Do you know by chance? I'm hoping it's not manual..

[Soundy 1]

Yeah, I don't see anything that indicates it supports auto-iris. It is a TDN camera so it will need an IR lens... the 3MP version is a 1/3" sensor though, so you don't HAVE to go to a 1/2" lens (it'll work, but it's not required).

[camera-newbie 0]

Thanks.. From your perspective is there any benefit to, at least in this case, using one over the other? I'll probably pop a note to IQEye (or I guess I could drive down there on Friday and pester them since they're only about 50-60 miles south of me here in So-Cal) and get the answer.. If it turns out I buy a lens with a DC iris but the camera uses a manual iris -- is it safe to assume they can't really be used together since there'd be no way to control the iris outside or jury-rigging a control circuit of some sort..?

 

I just sent a note to one of their guys -- hopefully I'll get an answer..

Edited March 14, 2012 by Guest

[Soundy 1]

If it turns out I buy a lens with a DC iris but the camera uses a manual iris -- is it safe to assume they can't really be used together since there'd be no way to control the iris outside or jury-rigging a control circuit of some sort..?

That is correct.

[camera-newbie 0]

Ok.. Got my reply from Bud at IQeye a little while ago..

 

All of our cameras have manual lenses. We don’t have an auto iris in the house. Thanks for your inquiry.

 

At least I know they respond to emails.. I sent an email to KT&C last week and haven't received any replies yet.. I'm not expecting one either at this point.

[Soundy 1]

That's one thing with IQ, I've always found their support responsive and very helpful.

[camera-newbie 0]

Good to know.. I've got a note into Pentax CCTV lens people in Denver asking some more lens questions.. The one issue with the small basler's (assuming you're using their recommended Aigis enclosure) is getting a lens that will also fit the enclosure -- some with the DC iris are a little iffy size-wise -- the computar I mentioned earlier may be a fraction of an inch too wide to fit -- I suppose I could try to 'adjust' the case to make it fit but will keep looking.. It's hard to find a IR corrected 2.8-12mm, F1.2 Varifocal DC Iris Megapixel lens apparently.. Many lens places just don't have the combination needed.. If I were in the market for a 5MP capable lens, my choices would be even more restricted unless you ditch the MP need and get a regular lens. Many places go up to 3MP and a few to 5MP from what I've seen..

 

P.S. I was reading the spec sheet for one of the Computer/Ganz lens and noticed the street addresses listed on the bottom -- their California office is located about 5 minutes from my house.. Go figure!