[miro]

Hello,

After unfrequent use of circular polarizers I discovered that my two Hoya CPL have some scratches at front side . At the same time I don’t have any scratches on all my lenses equipped with different brands of UV filters.

I have

1. Hoya 52mm HMC circular polarizer - green label

2. Hoya 77mm Pro1-Digital - blue label. I have some doubt about this filter /maybe fake/.



My question are

1. Where is located the polarizing film on Hoya filters?

a. front side of the glass

b. back side of the glass

c. between two glasses as B+W

2. Should I handle CPL filters with extra special care? /since I don’t have any scratches at my lenses and UV filters./

3. How durable are other brands of CPL. E.g. B+W or Helioplan?



Thanks in advance

Miro

[joachim]

[quote name='miro' timestamp='1283511570' post='2446']

Hello,

After unfrequent use of circular polarizers I discovered that my two Hoya CPL have some scratches at front side . At the same time I don’t have any scratches on all my lenses equipped with different brands of UV filters.

I have

1. Hoya 52mm HMC circular polarizer - green label

2. Hoya 77mm Pro1-Digital - blue label. I have some doubt about this filter /maybe fake/.



My question are

1. Where is located the polarizing film on Hoya filters?

a. front side of the glass

b. back side of the glass

c. between two glasses as B+W

2. Should I handle CPL filters with extra special care? /since I don’t have any scratches at my lenses and UV filters./

3. How durable are other brands of CPL. E.g. B+W or Helioplan?



Thanks in advance

Miro

[/quote]



I have various Hoya HMC filters and a few of them have scratches from cleaning. I read similar reports from other people. Hoya HMC just doesn't seem to be very hard and needing some care when cleaning. Since they are cheap, I keep buying them and chuck them when it gets to bad. I thought the coating of the Pro1 was harder, but maybe not.



I recently got some B+W MRC. So far no issues.

[Brightcolours]

[quote name='miro' timestamp='1283511570' post='2446']

Hello,

After unfrequent use of circular polarizers I discovered that my two Hoya CPL have some scratches at front side . At the same time I don’t have any scratches on all my lenses equipped with different brands of UV filters.

I have

1. Hoya 52mm HMC circular polarizer - green label

2. Hoya 77mm Pro1-Digital - blue label. I have some doubt about this filter /maybe fake/.



My question are

1. Where is located the polarizing film on Hoya filters?

a. front side of the glass

b. back side of the glass

c. between two glasses as B+W

2. Should I handle CPL filters with extra special care? /since I don’t have any scratches at my lenses and UV filters./

3. How durable are other brands of CPL. E.g. B+W or Helioplan?



Thanks in advance

Miro

[/quote]

I do not use any UV filters on any of my lenses, and none have scratches on the front element. My 67mm B&W circular pol. filter has no scratches, so I guess it must be that the Hoya coatings just are not very hard.

My Hama 77mm circ. pol. filter also has no scratches. I thought that Hama filters were actually Hoya made, though... But i also do not use that filter a lot. My Toshiba linear pol. filter also has no scratches.



The pol. film is sandwiched between glass, as far as I know (with all brands), you can not touch it.

[Guest]

[quote name='Brightcolours' timestamp='1283516988' post='2454']

The pol. film is sandwiched between glass, as far as I know (with all brands), you can not touch it.

[/quote]



Actually a circular polarizer comprises two thin plates glued together: a linear polarizer and a quarter-wave plate (whose optic axis is aligned at 45 deg to that of the linear polarizer).

[Brightcolours]

[quote name='thw' timestamp='1283520886' post='2455']

Actually a circular polarizer comprises two thin plates glued together: a linear polarizer and a quarter-wave plate (whose optic axis is aligned at 45 deg to that of the linear polarizer).

[/quote]

Hmm? A linear pol. filter still has the film sandwiched between 2 glass plates. Does not matter that a circular one adds something extra... <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/cool.gif' class='bbc_emoticon' alt='' />

[miro]

Murphy lows.... Scratches are on expensive filters only



Ok it seems that scratches are on coating only. It is locagal that hoya uses dual grass sandwich since CPL filters are ticker than UV.



Does somebody have experience with Hoya HD filers? It seems to be similar to B+W MRC

[popo]

[quote name='miro' timestamp='1283529381' post='2458']

Does somebody have experience with Hoya HD filers? It seems to be similar to B+W MRC

[/quote]

I got one each of the HD UV and polariser. Main benefit of them I see is they're quite thinner than budget HMC types. Haven't really stressed them beyond that.

[popo]

[quote name='Brightcolours' timestamp='1283516988' post='2454']

I do not use any UV filters on any of my lenses, and none have scratches on the front element.[/quote]

I used to think that too. Stopped using them once I found it caused flare in night shots. But I changed my mind again when a swan pecked the front of my brand new EF_S 15-85 leaving two small but visible marks on it. The hood was no use in that case. So now I use Hoya HMC UV(0) or UV© in wildlife cases. UV(N) coating doesn't seem as good at anti-reflection and seems to introduce a slight colour cast.

[Brightcolours]

[quote name='popo' timestamp='1283531672' post='2463']

I used to think that too. Stopped using them once I found it caused flare in night shots. But I changed my mind again when a swan pecked the front of my brand new EF_S 15-85 leaving two small but visible marks on it. The hood was no use in that case. So now I use Hoya HMC UV(0) or UV© in wildlife cases. UV(N) coating doesn't seem as good at anti-reflection and seems to introduce a slight colour cast.

[/quote]

Are you sure they wont normally clean off with lens cleaning fluid? They probably will...



Of course, nothing wrong using protective filters when there is actually something to protect against.

[popo]

[quote name='Brightcolours' timestamp='1283532685' post='2466']

Are you sure they wont normally clean off with lens cleaning fluid? They probably will...



Of course, nothing wrong using protective filters when there is actually something to protect against.

[/quote]

I've cleaned it several times with two types of fluid and they seem to be real scratches not juts marks. But they really are small you have to look for them to see them.



That of course did catch me by surprise, so now I'm more cautious when entering unknown areas.