Kodak Retina 1b vignette?

Laci Toth said:

Hi all,

I just swapped a Kodak Retina 1b and love it.
Would like to give Rollei Infrared a go and will use two rings to be able to use ir72 filter. As I need two step rings one 49-37 and the other 37-29.5, I’m wondering if I’ll face with vignetting problems or not?

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bernard_L said:

You can find out for yourself without even using film. Mount the two step rings and a clear (UV, haze) 49mm filter. Open back. Open shutter on B setting, diaphragm fully open. Facing a uniform surface (sky, wall), peek from the back, line of eyesight near each corner of the film gate; Can you see a darkening from the edge of the filter ring?

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Helge said:

Here’s what i did:
Get a plain glass filter holder for 29.5 filters, with the possibility of screwing in a shade. Like the Omag ones.

You really really need a shade for IR.

Get a Zomei 720nm 30.5mm https://www.ebay.com/itm/174348617441

It’s absolutely as good as the Hoya.
I have tested.
If it does let a smidgen (not that I can detect it) more visible light through, it’s only good with this film to lower the contrast a tiny amount and give the shadows a bit more information.

Take out the front ring of the filter. Flip the glass out onto a napkin, and held by the edges insert into the holder.
It should fit perfectly.
View attachment 269081

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Laci Toth said:

I don’t know if I understand how to do this.
So first I need a 29.5mm filter holder. I then screw this in the front of the lens. Then I need a 30.5mm ir filter which will fit in this holder. How can I take this ir filter out from the ring? Is there a tool or any tricks how to take that out?
If I succeed I then screw in a lens hood in the filter holder with the ir filter between the filter holder and the lens hood?

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Helge said:

Exactly.
The glass on most filters, including this one is easily removable with a slide caliber (buy a cheap plastic one for this job) or lens spanner tool, put into the notches, on either side of the retaining ring.
You can even use pointy scissors if you have a steady hand and are not planning on using the filter ring.

Edit. Sorry, just saw that it’s a 27 filter holder I have. It will not work for you on a Ib.
Your best bet is to get a 29.5 to 37mm converter for the Zomei filter, and then a push on shade.
I’m not even completely sure a larger filter will fit within the folding bed. Under any circumstance it will look and work better with a smaller filter.

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