How to set up varifocal lense?

[robert 0]

The problem is - I can`t turn by hand lets say 1/10 of mm to get perfect sharpness. How do you do that? Any tools?

[rapid 0]

what is the focal length of the lens?

what format is the lens and camera?

[robert 0]

what is the focal length of the lens?

what format is the lens and camera?

 

Well, it doesn`t make any difference, does it? Its just that you cannot turn ring for example by 1/10 of mm to get it in focus.

 

But its 4-8mm, 2/3 lense for megapixel camera Arecont Vision with 1/2 sensor.

[rapid 0]

the black screw at the back of the lens....twist counter clockwise slightly to loosen the screw....should be able to rotate rear ring now

[robert 0]

the black screw at the back of the lens....twist counter clockwise slightly to loosen the screw....should be able to rotate rear ring now

 

I know that and I can rotate rings. But to get perfect focus you need to turn rings by some 0.01mm 0 but how do you do that? I personally cannot.

Edited November 23, 2008 by Guest

[rapid 0]

Sounds like camera/lens back focus issue.

Robert....Can you slightly unscrew the lens from the camera mount?

Don't know this camera, but is there a brass lens mount ring between camera and lens?

[robert 0]

Sounds like camera/lens back focus issue.

Robert....Can you slightly unscrew the lens from the camera mount?

Don't know this camera, but is there a brass lens mount ring between camera and lens?

 

Yes I can. I tried with ring, without ring, but picture doesn`t seem to be 100% perfect sharp, a littlebit smooth. Its fine on one camera, but on other 2 not.

[rapid 0]

do you have any 1/2 format lenses handy?

the 2/3 may be giving you some distortion at the 4mm, although it should be fine....just a suggestion.

[robert 0]

do you have any 1/2 format lenses handy?

the 2/3 may be giving you some distortion at the 4mm, although it should be fine....just a suggestion.

 

No, i dont have any other lense. I was probably very lucky to get in focus one of them. But should it be much more easy to get varifocal lense in focus?

[ak357 0]

Sounds like camera/lens back focus issue.

Robert....Can you slightly unscrew the lens from the camera mount?

Don't know this camera, but is there a brass lens mount ring between camera and lens?

 

Yes I can. I tried with ring, without ring, but picture doesn`t seem to be 100% perfect sharp, a littlebit smooth. Its fine on one camera, but on other 2 not.

 

I can feel your pain

just finish 5 -3100 DN install

was using chinese 1/2 '' lenses

in general I dont think i will be using Arecont anymore

have a look

pix was resized 1024x768

 

http://i305.photobucket.com/albums/nn217/ak357/1024x768.jpg

 

as u can see far away is kinda blurry but i cant do any better

customer like it so for now

we decide to leave it

Edited November 23, 2008 by Guest

[robert 0]

Sounds like camera/lens back focus issue.

Robert....Can you slightly unscrew the lens from the camera mount?

Don't know this camera, but is there a brass lens mount ring between camera and lens?

 

Yes I can. I tried with ring, without ring, but picture doesn`t seem to be 100% perfect sharp, a littlebit smooth. Its fine on one camera, but on other 2 not.

 

I can feel your pain

just finish 5 -3100 DN install

was using chinese 1/2 '' lenses

in general I dont think i will be using Arecont anymore

have a look

pix was resize 1024x768

 

http://i305.photobucket.com/albums/nn217/ak357/1024x768.jpg

 

HUGE mistake - using anything else than Computar, Tamron, Fujinon Everthying else - rubbish, not talking about some kind of Chinese miracles

But picture seems to be ok to me.

 

What tools do you use to focus varifocal lenses?

[ak357 0]

Sounds like camera/lens back focus issue.

Robert....Can you slightly unscrew the lens from the camera mount?

Don't know this camera, but is there a brass lens mount ring between camera and lens?

 

Yes I can. I tried with ring, without ring, but picture doesn`t seem to be 100% perfect sharp, a littlebit smooth. Its fine on one camera, but on other 2 not.

 

I can feel your pain

just finish 5 -3100 DN install

was using chinese 1/2 '' lenses

in general I dont think i will be using Arecont anymore

have a look

pix was resize 1024x768

 

http://i305.photobucket.com/albums/nn217/ak357/1024x768.jpg

 

HUGE mistake - using anything else than Computar, Tamron, Fujinon Everthying else - rubbish, not talking about some kind of Chinese miracles

But picture seems to be ok to me.

 

What tools do you use to focus varifocal lenses?

 

I do have in stock all "famous" lenses

cant see big difference

I use my hands as "tools"

dont have big problem to focus

[rapid 0]

although the lense is rated for 4 mm, I've come across something similar where I had to sacrifice the focal length to say 4.2 mm, so that I had enough realestate to focus the lens.

[robert 0]

Sounds like camera/lens back focus issue.

Robert....Can you slightly unscrew the lens from the camera mount?

Don't know this camera, but is there a brass lens mount ring between camera and lens?

 

Yes I can. I tried with ring, without ring, but picture doesn`t seem to be 100% perfect sharp, a littlebit smooth. Its fine on one camera, but on other 2 not.

 

I can feel your pain

just finish 5 -3100 DN install

was using chinese 1/2 '' lenses

in general I dont think i will be using Arecont anymore

have a look

pix was resize 1024x768

 

http://i305.photobucket.com/albums/nn217/ak357/1024x768.jpg

 

HUGE mistake - using anything else than Computar, Tamron, Fujinon Everthying else - rubbish, not talking about some kind of Chinese miracles

But picture seems to be ok to me.

 

What tools do you use to focus varifocal lenses?

 

I do have in stock all "famous" lenses

cant see big difference

I use my hands as "tools"

dont have big problem to focus

 

But do you notice that varifocal lenses have less sharper images than fixed focal lenght lenses?

[robert 0]

although the lense is rated for 4 mm, I've come across something similar where I had to sacrifice the focal length to say 4.2 mm, so that I had enough realestate to focus the lens.

 

Arecont Vision 1/2 camera +Computar 4-8mm varifocal 2/3 lense. I dont remember wich end, but 4 or 8 mm - complete fog, so you dont really get full range 4-8. I think probably because of format difference. I have few mm less to play with.

[ak357 0]

[

But do you notice that varifocal lenses have less sharper images than fixed focal lenght lenses?

 

yes i kinda agree with u

and impossble to get focus from zoom in to zoom out range

[robert 0]

I even tried to use Arecont software, digital zoom and then focusing - but still no success on 2 cameras, I dont like it myself, so I wont leave it like that for a customer. Just one camera looks super sharp, great, I love it.

[ak357 0]

I even tried to use Arecont software, digital zoom and then focusing - but still no success on 2 cameras, I dont like it myself, so I wont leave it like that for a customer. Just one camera looks super sharp, great, I love it.

 

any pix samples ?

What soft do u use ?

[robert 0]

This is image from the camera i did get in focus and I do like it myself. I dont have those out in focus at the moment.

 

http://img517.imageshack.us/img517/7559/kr1qk8.jpg

[robert 0]

I even tried to use Arecont software, digital zoom and then focusing - but still no success on 2 cameras, I dont like it myself, so I wont leave it like that for a customer. Just one camera looks super sharp, great, I love it.

 

any pix samples ?

What soft do u use ?

 

Luxriot - rocks. Based on Arecont SDK.

[ak357 0]

quote]

Luxriot - rocks. Based on Arecont SDK.

 

Thx

 

I use original Arecont or ExacqVision

 

just for fun

I can get u video clip done by soft which use true H.264

just incredible

10 frames per second for 20 sec at 1600x1200

only about 2.2 MB

[robert 0]

Luxriot - rocks. Based on Arecont SDK.

 

Thx

 

I use original Arecont or ExacqVision

 

I can get u video clip done by soft which use true H.264

just incredible

10 frames per second for 20 sec at 1600x1200

only about 2.2 MB

 

woow, thats impressive Luxriot are going to release new version in next few weeks, H264 will be supported there.

Please drop me that video to rbsarg AT gmail.com

[robert 0]

I was looking at ExacqVision once, load of video on youtube.

But it did seem a bit complicated to me.

Whats your experience with it? Have you used Luxriot?

[ak357 0]

I was looking at ExacqVision once, load of video on youtube.

But it did seem a bit complicated to me.

Whats your experience with it? Have you used Luxriot?

 

Hmm i have opposite opinion

Luxriot is kinda awkward and Exacq no problem

but I did not play with Luxriot for long time

I guess I should give them another try

[robert 0]

Then I should look at it again. I cannot download any software from their website, its asking for username and password.

Do you know where I can get some demo or trial?

 

What about price - which one is cheaper?