not vignetting filter+hood combo for P645 35/3.5 lens?

[gbaida]

Hi Photonetters,

 

Recently I used Pentax 645 35/3.5 manual focus lens with 77 mm Tiffen

81A warming filter and 77 mm rubber wide-angle no-brand-name hood. I

got some corner vignetting on some of my wide-angle shots. I suppose

that it probably happened when both the filter and hood were used.

Probably focusing distance also might influence a degree of the

vignetting.

 

Can you recommend me filter+hood combination for P645 35 mm lens,

which would allow me to avoid vignetting?

 

I have learned that Pentax makes its own 77 mm wide-angle rubber

hood, probably namely for the 35/3.5 lens. Any info about it? Maybe I

have to use a step-up ring to 82mm and use bigger hood or even bigger

filter? The Tiffen filter has pretty thick mount. It is thicker than

the 58mm B+W SE (or ES) filter I have. I also have 58mm Pentax

skylight filter which has the slimmest mount of all of them. I do not

know however if the mount thickness varies with the diameter. Are

Heliopan filters thinner than those of Pentax? I am quite satisfied

with Pentax filters as judged by apparent quality, slim mount and

lower level of light reflected from them. But Pentax makes only 81A

filters and I do not know how identical or different are their from

other 81As "by their color" and if I could complement Pentax's 81A

with 81B from Heliopan or elsewhere. So I might have to choose one

brand for the system.

 

 

I would appreciate your advice,

[andrew_schank]

I had the pentax hood and it was useless. In general, hoods on superwides are ineffective, as they hardly shade the front element at all, (or they would cause vignetting). Use the lens without the hood and remove the filter if shooting directly into the sun. Most common Tiffen filters are uncoated and I do not recommend them.