Split image filter?

I'm wondering if it's possible to buy a proper split image filter designed for accuracy? In this video this guy has made something similar to what I'm looking for.
However, for what I want to try and achieve, I really need it to be dead accurate when you rotate it for the second exposure, otherwise there will be a visable line in the photo.
What I was hoping to do was to go back to a tube station and do this photo again, but try and achieve the same effect all analogue and straight out of the camera. I'd need a split image filter and probably one that clicks in place so you know you have it on the other half of the frame exactly. Then I can have the camera on a sturdy tripod, very carefully move the filter to the other side, wait for a second train and expose for the same amount of time at the same aperture.
Shooting at f/11 with an ultra-wide angle lens there wont be that much margin for error. Does anyone make such a filter, because I'm struggling to find one.

I have not come across such. Have you considered making arrests yourself?
For instance with a leave spring and two indents? Or even faster working, but theoretically a tiny bit less acurate, with a pin and two pin arrests?

A different approach would be a sliding shade with an opening, and again two arrests.

You can search for Double Exposure Filter in Google and you should get some results (depending on where you are located)

I got the following:




https://www.bhphotovideo.com/c/product/1416568-REG/nisha_de67_67mm_double_exposure_attachment.html

https://www.ebay.com/itm/2010904568...VY8PF2iboZ65/4xZx2cVuqXerfc=|tkp:BFBMqILu3sRg

Foc, the OP's issue is that he wants the change of setting:
-) fast
-) precise
-) during looking through the finder

That is why I hinted at arrests.

foc's idea is a good 'un.
looking through the finder.........good.
Fast, not needed; ..................he's waiting for another train.

precise? with interchangeable screen, mark or scribe a line on a spare screen.
.......or....scribe a line on the filter ring.

Yes, I misread that "second", thinking that was planning two takes within a second, at highest edge precision.

I'm surprised such a filter, with positive clicks so you know it gone exactly to the other side doesn't exist.
I'm not sure if this does that or not.

I won't repeat the suggestions for getting the line accurate, but I will mention that diffusing the line means as little DOF as possible. The line will be more apparent as you stop down and as the angle of view increases -- so use as long a lens as possible, and as wide an aperture as possible.

Sonia double-exposure filters have a handle -- like some PL filters -- that might help:

https://www.ebay.com/itm/165595933354

That's just it, it's going to wide angle and small aperture, I could of course use an ND filter, it's still likely to be f4 or f5.6.

The Kood one looks like it might have clicks for accuracy however if it's on a Cokin P mount I'd have to be really careful not to nudge that.

As the parting line between the two shots doesn't always pass through the middle of the image, nor is it always straight, I don't see much utility in the pre-made masks.

Attach a gel filter holder to the lens to give a flat working surface in front of the lens. Cut a bit of black paper with the desired parting line. Move the first half of the mask into position, looking through the finder to line it up, and tape it into position. Take the shot. Slide the other half of the mask so it is tight against the edge of the first mask. Tape the second mask into place, remove the first mask and take the second shot.

ajuk said:

I'm surprised such a filter, with positive clicks so you know it gone exactly to the other side doesn't exist.

Click to expand...

The typical approach with any split-image attachment is to set the camera on a tripod, carefully check at subjects, backgronds etc. where the dividing line must be located, even which shape it must have . Then, in the most simple case, just rotate the divider by 180°, or even mount successively two (or more...) complementary masks.
Thus there is no timeliness, and there is no problem viewing and adjusting the attachment.

Of course arrests of some kind are in any case benefitial, but for the most common cases one (read: the manufacturer) may wonder if it pays off economically for him.

I would make two little marks like this (- - ) that line up exactly on your filter w/ a bit of paint on a small brush. You'll have to look at it to know it's aligned, but I don't see that as an issue. You should still be able to get that shot.