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View Full Version : Circular polarising filter for the Kowa 8.5mm f2.8


-PQ-
16th March 2015, 08:57 PM
Hi,

Does anyone know of an 86mm circular polarising filter that will fit within the Kowa 8.5mm f2.8 lens hood? (For those who are not aware, you cannot attach a filter directly to this particular lens, it must be to the hood instead.)

I have just taken delivery of a Marumi DHG polarising filter and unfortunately it is too wide. The inside of the hood tapers and the filter will jam inside the hood before it reaches the mounting thread. Amazingly, it does not vignette fitted like this. However, I think jamming the filter in in this way is unsatisfactory as it is not convenient and obviously in use it may fall out.

The outside diameter of the Marumi DHG is 90mm and I am certain that a filter with an outside diameter of 89.5mm will fit (only half a millimetre less!).

If anyone knows of a filter that will fit, or is able to accurately measure their 86mm polarising filter, I would appreciate the information.

Thanks in advance.

PQ

Zuiko
16th March 2015, 09:36 PM
Hi PQ,

I'm afraid I can't help, my largest filter is 72mm, but welcome to the forum. Is there a camera shop near to where you live that you could visit, to check their stock?

-PQ-
16th March 2015, 09:49 PM
Hi John,

Thanks for the reply.

Funnily enough I don't live to far from you, I live in Southend on Sea. There used to be a good camera shop round here but it closed down about twenty years ago! Likely London would be my best bet for a shop but if you know of any nearer I would be grateful to find out.

PQ

Zuiko
16th March 2015, 10:06 PM
The nearest camera shop to you that I know of is Cameraworld in Chelmsford, but it is probably easier for you to go to London. If you do decide to try Cameraworld, phone them first to make sure they have filters of that size in stock. Their number is 01245 255510.

I was in Southend with my local camera club a couple of weeks ago. We started at Shoeburyness for the sunrise, moved to Leigh, then finished on Southend Pier.

pdk42
16th March 2015, 11:17 PM
Ah - you have the Kowa 8.5! !! I'd really be interested in hearing your thoughts on it - esp if you can put up some full res samples. I'm particularly interested to see what the corner rwsolution is like. I'd also be really interested to know how you get on with the filter fitting. It's its ability to take filters that really gets my attention.

Thanks!

-PQ-
17th March 2015, 06:57 AM
The nearest camera shop to you that I know of is Cameraworld in Chelmsford, but it is probably easier for you to go to London. If you do decide to try Cameraworld, phone them first to make sure they have filters of that size in stock. Their number is 01245 255510.

I was in Southend with my local camera club a couple of weeks ago. We started at Shoeburyness for the sunrise, moved to Leigh, then finished on Southend Pier.

I'll give Cameraworld a call, it's actually not to far. Thanks for the info.

I live just by the North end of Shoebury East Beach and the MOD site, likely you walked very near my house!

-PQ-
17th March 2015, 06:58 AM
Ah - you have the Kowa 8.5! !! I'd really be interested in hearing your thoughts on it - esp if you can put up some full res samples. I'm particularly interested to see what the corner rwsolution is like. I'd also be really interested to know how you get on with the filter fitting. It's its ability to take filters that really gets my attention.

Thanks!

Straight away compared to the Panasonic 7-14 I can see a difference, which surprises me as I have found that an excellent wide angle lens, and it is definitely better than either the Sigma 10-20 or Nikon 12-24 DX on my old D200 in every way (other than the lack of zoom obviously). I don't think it has quite the contrast as the Voigtlanders I have but I think it is not very far off. Perhaps it is a bit early to tell as i've only had it a week but so far so good and I am very happy with it.

-PQ-
17th March 2015, 07:04 AM
Apparently I need two more posts to be able to post an image, so here's the first!

-PQ-
17th March 2015, 07:04 AM
and the second... (after a 30 second wait!)

-PQ-
17th March 2015, 07:06 AM
https://www.dropbox.com/s/81hcsq1mdefygvj/P3110918.jpg?dl=0

-PQ-
17th March 2015, 07:26 AM
Well that was a fail, I guess the https dropbox link is not recognised within the image tags. Here is a link to one image taken last week with the Kowa 8.5:

https://www.dropbox.com/s/81hcsq1mdefygvj/P3110918.jpg?dl=0

pdk42
17th March 2015, 08:48 AM
Thanks for posting that. It's pretty sharp into the corners. There's a bit of CA, but LR removed that pretty well. It's also impressively short of distortions (and since it's a manual lens, there are no automatic software corrections).

It seems that there's not too much focus field curvature either. What aperture was it taken at?

BTW - is there a good reason you want a CPL filter? They don't tend to work too well on UWAs in my experience. Now, a 10-stop ND - that's a different matter!

PaulB
17th March 2015, 03:14 PM
SRB do 86mm spacing rings which would move your polariser out of the hood a bit and possibly let you use the marumi filter. You'd have to contact them to ask the O.D. of the spacer though.
http://srb-photographic.co.uk/86mm-fixed-spacer-ring-5713-p.asp

Could also cause vignetting too I guess.

mstphoto
17th March 2015, 04:39 PM
I've never found polarisers to be suitable for wide angles - even more so for your 8mm
They cause uneven polarisation across the frame ;)

Mike

-PQ-
17th March 2015, 10:42 PM
Hi all,

Thanks for the feedback re a polarising filter on a wide angle.

In the past I have used a polarising filter when on board sailing yachts to reduce the large amount of glare caused by shiny white gelcoat in the Mediterranean sun. The glare can throw the metering off and also create too large a dynamic range for a digital camera to handle. Obviously the cramped space on a yacht means that wide angle lenses are very useful and so I have often used a polarising filter on my Sigma 10-20mm with my Nikon D200.

I guess I may not have noticed any ill effects as the focus of that type of shot is likely what is on board the yacht and in the centre of the image rather than the sky?

However, having said all that, I have been enjoying the effect of a polarising filter on my two Voigtlander lenses (17.5mm and 42.5mm) while taking scenic shots and was hopping that I could get the same effect with the Kowa 8.5mm.

PQ

-PQ-
17th March 2015, 10:47 PM
What aperture was it taken at?

I did not record the aperture but I'm fairly sure that it was f8, but it could have been a stop slower. The ISO was 200 and the shutter speed was 1/100 second.

You are right about the CA, I'm not sure why I hadn't removed it actually!

Zuiko
17th March 2015, 11:47 PM
You are right about the CA, I'm not sure why I hadn't removed it actually!



It's good that you left it as it gives an accurate rendition of how the lens performs before any enhancement in pp. :)