Mittwoch, 7. Mai 2014

CCTV Wide Angle For Nikon 1 J2


In one of my videos I tried to take a star timelapse video with my Nikon 1 J2 . The lens I used was the standard NIKKOR 10-30 F3.5. I wasn't really satisfied with the result. A major reason was that I didn't set the focus correctly but furthermore haven't I been able to get enough sky into the photos. So I needed a lens with a wider angle.

Currently the only wide angle lens for the Nikon 1 series it the NIKKOR 6.7-13 F3.5. Unfortunately it's cost of about €450,- make it unaffordable for me. I found out that some people successfully use CCTV lenses from security cameras. Unfortunately they usually don't use wide angle lenses and especially not with a Nikon 1. So I had to do some testing on my own.

Timelapse video of a trip to Sweden

CCTV lenses are available for different sensor sizes. Accordingly the first thing to find out was which one of them works best with my camera. My impression is that 2/3" is the smallest you would like to use as it already causes some severe vignetting. If you have the choice better go for 1".

I had the great opportunity to test three different lenses. The first one was a €10,- no name 8mm 1/1.3 lens. As second I had a €50,- VT 8mm 1/1.3 and as third one a €100,- Computar 8mm 1/1.4. All of them were for 2/3" sensors. Unfortunately they did not have any model numbers on them. Finally I needed a €10,- CCTV adapter.

No name 8mm 1/1.3, VT 8mm 1/1.3, Computar 8mm 1/1.4 and CCTV adapter

The camera was set up on a tripod and the pictures taken by self timer to prevent shakiness. ISO was set to 100 as I didn't want grain to effect the result. I shot in JPEG finest quality and highest resolution. Lighting was pure daylight from left behind. As first scenario I chose a close-up on the lowest possible F-value.

As you can see the no name lens offers a very shallow depth of field with a lot of bokeh. The image is sharp in the center where I had the focus. It has quite some vignetting but that's the same for all three lenses I tested.

No name F1.3

The VT image looks very similar but the bokeh structure is a bit nicer in my eyes.

VT F1.3
A little drawback of the Computar may be that its F-value goes only down to 1.4 compared to 1.3 of the other lenses but I don't find it noticeable. The image is very crisp in the focus area and the depth of field is similar to the other lenses. For me the bokeh structure is just as nice as the one of the VT.

Computar F1.4

Now I shot the close-up with F8 to achieve a higher depth of field. You will notice that the image from the no name lens is sharp all over but gets a bit blurry towards the vignetting.

No name F8
The VT doesn't show much difference in comparison.

VT F8
When it comes to the Computar one can see that the vignetting is much cleaner. Some people may think that this is a disadvantage as they like a soft vignette. My opinion is that I prefer this result as a soft vignette can easily be applied in post.

Computar F8
My second scenario was a landscape shot where I set the focus to infinity. The first run was again with the lowest possible F-value. I was a bit disappointed by the result from the no name lens as it was blurry all over.

No name F1.3
The VT didn't show much of a difference although there was at least something sharp in the center.
VT F1.3
As it came to the Computar I could see a tremendously better result. The sharpness was not overwhelming but nice enough for my purpose. Furthermore do I like the colors a lot better than from the other ones which look a bit dull.

Computar F1.4
In the following I switched to F6 to see whether I could get at least some sharpness out of the cheaper lenses. The result for the no name lens was really better but still not very good.

No name F6
For the VT lense the change in the F-value brought much more sharpness but it's very limited to a center area of the image. If you look at the building in the right of the background you could get the impression that the lens hasn't much sharpness in the distance at all. Instead look at the roof top that is hardly captured in the center and you will find that this looks pleasingly sharp.

VT F6
Considering sharpness and colors the Computar really outperforms the other two lenses in this run.

Computar F6
My conclusion is that you get what you pay for. CCTV lenses can be really cheap but lack image quality as well. Even the Computar may not be able to compete with the regular NIKKOR wide angle lense. I was able to get another used 8mm VT lense from ebay for €15,-. As video doesn't need that much of a high resolution I will try if I can get some nice night sky sequences out of it when I crop the images.

Update:

I had the time and it was suitable weather to make a star photo with the VT. The stars already show a bit of movement so the exposure time of 25 seconds was a bit too long. I didn't apply any post editing on this one but a median filter gets you rid of most noise.

VT | Exposure: 25 | F6 | ISO 400 | Focal Length : 8 mm

by XXLRay