[ablundon]

Not sure if it will be helpful or not but I decided to do a video of my unboxing and installation of a Canon S Type focusing screen from focusingscreen.com.

I also compare the new screen with the stock screen.

You Tube

You Tube

It might be a little long winded but I think it is very thorough.

I would appreciate any feed back as it is my first You Tube video.

Thanks,
AB

[newmikey]

I'm sorry but this may not be the best way of unboxing or installing. Couple of points I picked up on:
1. You put the finger cots on one finger each hand and then pick up the new screen with one protected and one unprotected finger (thumb & index) allowing skin grease from your unprotected finger to get on the screen. The finger protectors are designed to go on two fingers of the same hand.
2. You see a difference in DOF and associate that with the new screen. That seems highly unlikely. DOF is determined by focal length and aperture only. Something in your test setup must have changed, possibly due to twisting the lens in-mount as you described.
3. You used the 50mm/f1.7 SMC-A lens and advise to "twist it slightly to disengage the aperture lever" in order to see the effect of using smaller apertures. This seems to be a rather haphazard way to go as the lever might still be partly engaged leading to spurious results.
4. The differences in screen brightness going from f1.7 to f11 seem to be too large to be explained by light-transmitting differences between the screens as such. More likely, the "twist" on the lens described above was less complete on the series shot with the stock screen causing the aperture to not close completely to its preset value. I have noticed large differences in- and around the central split-screen areas on several focussing screens before but the overal brightness of the screen itself showed much smaller variations whether I was using the $20 Ebay screen or the $100+ KatzEye screen. Your variation seems to be quite extreme to be honest.

A valliant attempt nevertheless!

[ablundon]

Thanks....
1. I'm glad you picked up on the finger cot thing...in my attempt I tried to follow the instructions on the focusingscreen.com website. On step 13 they have one cot on the left thumb. On step 15 they had one cot on the right index finger. I attempted to do the same. I think touching the edge of the screen like I did didn't cause any smudges. In hindsight, a part of latex gloves may have been better or additional cots. The recorded video was actually my first attempt.

2. The DOF that I mentioned is not the real DOF of the selected aperature, focal length and focus distance but rather a simulated DOF of the screen. Perhaps DOF was not the correct term to use but the new screen definitely shows OOF areas more blurry than the in focus areas and the plane of focus is much easier to see. That is the whole point of the screen.

3. The Twist the Lens method works fine. The lens was twisted sufficiently to disengage the lever. I also repeated the method using an M42 lens and got the same results.

4. I have read that the Canon S screen does get a lot darker at smaller apertures than other screens due to its ability to provide that thin focus plane a apertures larger than f/2.8. If you read the product description of the Canon S screens, it is an advertised fact that these screens get dark past f/2.8. I think my results are valid. Again, I tried this with an M42 lens at the it is noticeably darker than the stock at f/11.

Thanks for taking the time to respond!
AB

[Deep Green Sea]

Hey, as somebody who is expecting to take delivery of a K3 from focusingscreen.com for my K-r in the next couple of days, I found your video very interesting.

Of all the videos and picture instructions I have seen online, the procedure for opening the clamp is clearest in yor video. It's good to see results too.

I knew what you meant by DOF, when speaking about the S type, as I've researched these screens a lot. Also the rate of darkness to lens aperature that you've simulated seems consistent with what I've read on these screens too.

Well done, and very useful. Thanks

[Na Horuk]

I think its an ok video.

[lammie200]

Great job!

I was surprised that you needed shims. I initially tried to install one because, as you mentioned, the website instructions seem to direct you to install one. Mine was definitely not focussing properly so I removed the shim and it is spot on. The shims are a pain. I think that if shims would have been necessary for me I probably would have done the scotch tape on the edges method. I did notice the Canon screen is much thicker than the stock K-r screen, so it didn't surprise me that shims weren't necessary. But I guess that there are variations within the cameras themselves. Hence you needed shims.

I didn't use the tool at all. I found the tweezers sufficient for handling both screens. One thing that I would recommend is folding up a piece of lens paper and putting it on the mirror. As your video shows, the retainer bracket will fall all the way down on top of the mirror. It is almost impossible to keep that from happening. Dust is an issue as well. I just continued to use a blower through out the process and everythng seems clean.

[cola]

Paper to protect the mirror is needed AND another tipp is to put small adhesive tape stripes to the end of the tweezers, so that nothing can be damaged if you have more contact with the screen as only with the little grab edge at the right front.

[SyncGuy]

Don't you just love this screen? Hahaha.... It gave new life to all old lenses... :P

Congratulations!

[ablundon]

I was surprised that you needed shims.

So after a week of testing and using the screen I've noticed that the focus was still slightly back focused, and that was with 2 shims. I therefore decided to install all 3 supplied plastic shims with the kit.

Installing 3 of these light plastic shims on top of each other straight was quite a challenge. I would get all three placed on top of the screen and when I tried to close the bracket...the shims would dislodge and move and I'd have to start over. After about an hour of trying I finally got it.

The focus is now spot on using my 50 mm f/1.7.

It would be good for focusingscreen.com to include shims of varying thickness rather than 3 thin shims. That way you would only ever need to use one shim.

AB

[lammie200]

Installing 3 of these light plastic shims on top of each other straight was quite a challenge. I would get all three placed on top of the screen and when I tried to close the bracket...the shims would dislodge and move and I'd have to start over. After about an hour of trying I finally got it.

That's why I would have opted for scotch tape if I would have needed shims. I had enough trouble putting one in and was relieved that I didn't need any after all. Glad you got yours sorted.

[ablundon]

I'm not sure about scotch tape...if you put too much on how do you remove it without risking damage to the screen?

I found a single shim pretty easy to install...just wish they were different thicknesses.

[lammie200]

I'm not sure about scotch tape...if you put too much on how do you remove it without risking damage to the screen?

I found a single shim pretty easy to install...just wish they were different thicknesses.

I received three thin plastic ones and a thicker plastic one from focussingscreen.com IIRC.

The fellow that started all this Canon E screen info had a thread where described cutting the OEM Canon screen down to fit the K-5. He mentioned using scotch tape for shimming in his thread. It wouldn't be easy to do but thin strips on the two sides would work. Exacto knife skills are necessary I am sure.

[JohnBee]

It wouldn't be easy to do but thin strips on the two sides would work. Exacto knife skills are necessary I am sure.

Yes, that is exactly how its done.

I've adjusted my share of screens back in the day and all my fine tuning was done this way. I'd just take the shim and stick it to the piece of tape. I'd then trim the edges with my knife and it was good to go.

FTR. The reverse was done using Goo Gone, which disintegrates the tape in a mater of a second(easy-peezy)

[Deep Green Sea]

My K3 type focusing screen arrived from focusingscreen.com, with package contents the similar to what ablundon received above (with a different screen type).

My experience of installing it was mixed, so I thought I'd let you guys know how I got on.

I am usually fairly good with intricate kind of work, and I'm quite patient. I wanted to try and keep this procedure as smooth and quickly as possible, so as to avoid dust getting into my camera.

What I rather foolishly didn't anticipate though, was just how fiddly the tray that holds in the focusing screen is. More importantly, I didn't realise that when this tray is dropped down to its maximum ie. agains the mirror (protected of course), that the tray itself can easily come away from the camera.

So the initial removal of the factory screen and shim, and then the installation went without a hitch.

A quick test confirmed that at least one shim was going to be required, and that's where the fun started.

The supplied shims are light plastic, and quite flimsy. Trying to get the first one in place was what caused the tray to come out of the camera the first time, and I was lucky not to damage the new screen when this happened. I eventually managed to get the screen + 1 shim into the camera.

Another test confirmed than one shim wasn't enough.

After several failed attempts to get a second shim in place, and after the tray had come out of the camera again, and after the new focus screen had plenty of dust on it, I decided to chance my arm, and try the thicker metal factory shim on it's own.


I tried to blow away as much dust as I could from the new screen, and managed to get it installed with just the factory shim.

Focusing was perfect. The screen is great, apart from some annoying dust that's still there.

[ablundon]

So it seems the installation of multiple shims is a real issue. For me, the metal stock shim was too thick.

Also, since the shims are light plastic, they bend very easily. If the shim is slightly off you can still close the tray but the shim will get bent. If you need to remove and install a 2nd shim that is where the fun starts. Trying to place shims that are no longer flat but bent!

They could improve their product by including shims of varying thicknesses and even better...metal shims.

AB