Comments on: Long Exposure Daylight Photography Strong ND filter test

By: Dave Kennard

Dave Kennard — Sat, 19 Dec 2015 15:26:49 +0000

Hi Carl

I didn’t find any (or at least not much) reduction in image quality from the Zomei 10 stop, you can see my sharpness test results here: https://www.davidkennardphotography.com/blog/1016-long-exposure-daylight-photography-strong-nd-filter-test.xhtml#iq

Regards

Dave

By: Dave Kennard

Dave Kennard — Sat, 19 Dec 2015 15:07:43 +0000

In reply to Datum.

Hi Datum

I just took a photo without the filter, then one with the filter and with the camera settings adjusted to compensate for the filter. For the visible light images, this just meant adjusting the exposure by the number of stops the filter was rated at. For the IR photos, doing that just resulted in images overexposed, so I had to adjust the exposure down a couple of stops and try again. When I had an image with the filter that was around the same exposure as the image without the filter, I loaded both into ACR and used exposure compensation until both images looked the same in terms of exposure. Then I could use the amount of exposure compensation in ACR combined with the difference in exposure between the no filter and with filter images to work out the total difference in exposure between both images.

Regards

Dave

By: Datum

Datum — Sat, 19 Dec 2015 01:32:26 +0000

Great post!

Could you explain how you determined how many stops a filter actually blocks visible light as well as infrared?

One thing to keep in mind when using ND filters is the need to use a highly stable tripod, anything less might introduce blur that has nothing to do with the quality of the filters.

As for vignetting… It can easily and quickly be fixed in Lightroom so long the software has a profile for the lens.

Cheers

By: carl yammine

carl yammine — Fri, 18 Dec 2015 14:53:06 +0000

In reply to carl yammine.

thi si sthe site btw http://www.the-digital-picture.com/Reviews/10-Stop-Neutral-Density-Filter.aspx

By: carl yammine

carl yammine — Fri, 18 Dec 2015 14:52:15 +0000

Does the Zomei 10 stop reduce sharpness in anyway? for example look at the difference between those two pictures. You can clearly see how the hoya filter has reduced the sharpness in the picture which is a horrible deflect. Does the Zomei filters have this problem? Thanks

http://media.the-digital-picture.com/Images/Other/10-Stop-Neutral-Density-Filter/As-Shot/Control.jpg

http://media.the-digital-picture.com/Images/Other/10-Stop-Neutral-Density-Filter/As-Shot/Hoya.jpg

By: Dave Kennard

Dave Kennard — Mon, 27 Jul 2015 21:35:59 +0000

In reply to Bill Lanahan.

Hi Bill

The filters I’m using are screw thread rather than slot type filters. I did notice that vignetting increased with the filter, but as you can see from the images, it’s not particularly problematic.

Are you sure the vignetting is from the filter itself, and not the filter holder?

Dave

By: Bill Lanahan

Bill Lanahan — Mon, 27 Jul 2015 02:31:18 +0000

I just bought a Zomei 10 stop 4×4 ND filter and noticed two shortcomings. One was a color cast that I am not too worried about and I can easily take care of in Photoshop. The other was a strong dark vignetting around the border of the photo. This can also be fixed in Photoshop but is more difficult and raises the amount of time in editing. I would like to know if you noticed the vignetting in your filter?