20D - improved Katz Eye focsuing screen - Part 1/1

Started Aug 13, 2005 | Discussions
OP Doug Kerr Forum Pro • Posts: 20,898
AF point indications for the 10D

Hi, Jason,

Jason wrote:

Is it just a supply/demmand thing on why a 10d prism screen
couldn't be made with the focusing boxes added? Does the
technology exist outside of Canon's manufacturing plant to do that?

Certainly, but is a whole new layer (excuse the pun) of the manufacturing process, and evidently none of the suppliers have yet implemented it. It would require apparatus that perhaps they don't have at the present.

Best regards,

Doug

 Doug Kerr's gear list:Doug Kerr's gear list
Leica V-Lux 4
Rachael7 Forum Member • Posts: 82
Re: Sorry for the repetition, but what about the 10d?

Jason wrote:

I know that on the 10d, the focusing box screen gets sacrificed if
you want to add a split-prism focusing screen. The reason for this
is that the 20d has two separate screens, whereas the 10d only has
one.

Is it just a supply/demmand thing on why a 10d prism screen
couldn't be made with the focusing boxes added? Does the
technology exist outside of Canon's manufacturing plant to do that?

Hi Jason,

It is mainly a supply and demand problem. I have the technology to add the marks, although not the same exact way they are done by Canon. Unfortunately, in the quantities of screens that I sell, it is just too cost prohibitive to do at this point. I continue to research better ways of making the marks, but at this time there is no realistically priced option. Sorry about that.

Rachael Katz

PaulyOly Veteran Member • Posts: 7,723
That was the 50 1.8............

on the digital rebel, i shot that at f4 iso400 i think, i just shoved it up to the 20d viewfinder, i think i could have done better with my 100mm macro because there was still a lot of vignetting with the 50mm. Of course I sold the macro so that isn't going to happen.

I tried using autofocus, but couldn't get the right things infocus so i started using manual with better results.

this shows how the image splits in the center circle when out of focus.

but to my eye the wood railing looked more infocus yet I couldnt' seem to get that result, probably need a smaller aperture, but that would require mounting the camera to the 20d viewfinder. I try some smaller aperture shots after it stops raining. :^(

-- hide signature --

Narrow depth of field ahead
Use extreme caution

http://www.pbase.com/paulyoly/root

PaulyOly Veteran Member • Posts: 7,723
katz eye microprism?

Doug is the Katzeye microprism circle larger than the haoda or is it the same size? As you can see from the pic the haoda microprism is slightly larger than the 20d center circle.

-- hide signature --

Narrow depth of field ahead
Use extreme caution

http://www.pbase.com/paulyoly/root

OP Doug Kerr Forum Pro • Posts: 20,898
No, I meant on teh 20D (nt)
n/t
 Doug Kerr's gear list:Doug Kerr's gear list
Leica V-Lux 4
PaulyOly Veteran Member • Posts: 7,723
same question for the split prism part.........

is the split image circle larger with the katzeye screen?

-- hide signature --

Narrow depth of field ahead
Use extreme caution

http://www.pbase.com/paulyoly/root

PaulyOly Veteran Member • Posts: 7,723
sorry.......

I just realize what you meant. That was looking through the 200 2.8L.

I'll do one through the 50 1.4 or 135 f2L if the sun comes back out.
--

Dasigmaguy wrote:

However, the thing is that it is almost never necessary to > use anything higher than ISO200 as the SD10 has such a > good dynamic range.

Narrow depth of field ahead
Use extreme caution

http://www.pbase.com/paulyoly/root

OP Doug Kerr Forum Pro • Posts: 20,898
Re: katz eye microprism?

Hi, Pauly,

PaulyOly wrote:

Doug is the Katzeye microprism circle larger than the haoda or is
it the same size? As you can see from the pic the haoda microprism
is slightly larger than the 20d center circle.

On the Katz Eye screens, the split image prism has precisely the same diameter as the partial metering indciator circle. The radial "thickness" of the microprism collar is about 25% the radius of that circle (I haven't measured it) - that is, its outside diameter is about 125% that of the circle.

Thus evdiently the doodads on the Katz Eye screen are larger in diameter than those on the Hoada screen.

Best regards,

Doug

 Doug Kerr's gear list:Doug Kerr's gear list
Leica V-Lux 4
OP Doug Kerr Forum Pro • Posts: 20,898
Oops, my error

Hi, Pauly,

What I wrote was wrong (and it is wrong in my report as well!).

In the Katz Eye screen, the OD of the microprism collar is identical to the diamater of the Partial metering circle. It is much the same as seen on the Haoda screen.

The split prism is about 75% that diamater.

Sorry for the confusion.

Best regards,

Doug

 Doug Kerr's gear list:Doug Kerr's gear list
Leica V-Lux 4
David Kieltyka
David Kieltyka Veteran Member • Posts: 5,434
Just installed my Katz Eye screen

Came today...yay! The installation, following Doug's instructions, was quite easy. Except that I managed to install the screen wrong-side-up the first time and had to do it over again. When I removed the screen to flip it over the shim fell out too so I had to put that back in as well. But it's all set now and the screen works great.

Here are two test shots with my modded 20D and two of my favorite Pentax M42 screwmount lenses. I took the first with an SMC Takumar 135mm f/2.5, lens wide open. The subject matter is my usual long-distance test target: a church building about 80m from my backyard fence.

And here's a full-res crop from the point-of-focus:

Note that this is a lens not designed for flat-out performance wide open. Pentax lenses typically trade off some resolution & contrast at wider apertures for smooth out-of-focus rendition (bokeh). Yet it's still pretty darn good. Note also that it cost me US$75.

I took the second shot with a Super Takumar 55mm f/2, also wide open. This is a late Super Tak with the same coating technology as the SMC (Super MultiCoated) version. I deliberately put my dad in front of a busy background to see what the out-of-focus character would be like.

And again a full-res crop from the point-of-focus (the glasses):

I think the 55mm will make a very nice portrait lens on the 20D. Again it's not razor sharp wide open but this is a plus for people pics. Cost: US$25.

-Dave-

 David Kieltyka's gear list:David Kieltyka's gear list
Leica M9-P Leica M8.2 Pentax 645D Pentax 645Z Panasonic Lumix DMC-GX8 +8 more
OP Doug Kerr Forum Pro • Posts: 20,898
Good show!

Hi, David,

David Kieltyka wrote:

Came today...yay! The installation, following Doug's instructions,
was quite easy. Except that I managed to install the screen
wrong-side-up the first time and had to do it over again.

I hate to ask it this way, but were my instructions in that regard wrong, or unclear, or confusuing, or did you just not pay attention?

Best regards,

Doug

 Doug Kerr's gear list:Doug Kerr's gear list
Leica V-Lux 4
David Kieltyka
David Kieltyka Veteran Member • Posts: 5,434
Re: Good show!

Doug Kerr wrote:

David Kieltyka wrote:

Came today...yay! The installation, following Doug's instructions,
was quite easy. Except that I managed to install the screen
wrong-side-up the first time and had to do it over again.

I hate to ask it this way, but were my instructions in that regard
wrong, or unclear, or confusing, or did you just not pay attention?

I'm not sure. I think I flipped the screen over without realizing it while giving it some air blasts with my blower just prior to installation.

Your suggestion to insert a paper guard into the lens mount during installation worked out real well. Thanks!

-Dave-

 David Kieltyka's gear list:David Kieltyka's gear list
Leica M9-P Leica M8.2 Pentax 645D Pentax 645Z Panasonic Lumix DMC-GX8 +8 more
David Kieltyka
David Kieltyka Veteran Member • Posts: 5,434
Forgot to mention

I'm impressed with how the split-image behaves when I stop down. Even at f/11, at least with longer lenses, it doesn't black out, though you have to position your eye just right to keep both halves equally bright. This is good stuff...even my Contax (and Leica back when I used Leica SLRs) split-image focusers black out just past f/5.6.

-Dave-

 David Kieltyka's gear list:David Kieltyka's gear list
Leica M9-P Leica M8.2 Pentax 645D Pentax 645Z Panasonic Lumix DMC-GX8 +8 more
OP Doug Kerr Forum Pro • Posts: 20,898
Good to hear (nt)
n/t
 Doug Kerr's gear list:Doug Kerr's gear list
Leica V-Lux 4
OP Doug Kerr Forum Pro • Posts: 20,898
Re: Good show!

Hi, DAvid,

David Kieltyka wrote:

I'm not sure. I think I flipped the screen over without
realizing it while giving it some air blasts with my blower just
prior to installation.

I's easy to do. I blow it off and then set in place on the paper pad, paying attention at that time to orientation. (Note the order of steps 8 and 9 in my instrauctions - that's why it is that way!)

Your suggestion to insert a paper guard into the lens mount during
installation worked out real well. Thanks!

Glad that worked. I myself get skin oil, jelly fromf lunch, etc. on everything I work with, so for me this prophylactic practice is a ncesssity!

Best regards,

Doug

 Doug Kerr's gear list:Doug Kerr's gear list
Leica V-Lux 4
rachp Senior Member • Posts: 1,821
Improved Katz Eye focsuing screen

I just installed my new screen! It was soooo easy and thank goodness it was easy because I have to do it again!!!

Doug's instructions are perfect and easy to follow. All I can say is DO NOT skip his step on blowing off the screen. I didn't have a bulb blower and skipped that part. Now I have to pull the screen and clean it and reinstall it First, I have to get a blower

I cannot describe how easy it was!! Covering the mirror with the paper is a lifesaver - I would have never thought to do that. The toothpick is a wonderful tool! Get your own tweezers - don't rely on the supplied tweezers (maybe I am not smart enough but I couldn't figure them out)! I had more difficulty cleaning my sensor for the first time than I did installing this screen!!

The screen is amazing!! Using the new screen, I can see that my AF seems to be off just a tiny bit - I cannot wait to give it a try w/Macro. Don't hesitate to buy this product - I got the HiLux for $150 and it is worth every penny (and more)! Wonderful product Rachael!!!
--
Rachel
CATS member #51 > ^..^
Hummingbird Hunter #6

jerryk Veteran Member • Posts: 6,625
Re: Just installed my Katz Eye screen

What is the difference between the focus you obtain manually with what the camera does automatically?

-- hide signature --

Canon 20D owner
jerryk.smugmug.com

David Kieltyka
David Kieltyka Veteran Member • Posts: 5,434
Re: Just installed my Katz Eye screen

jerryk wrote:

What is the difference between the focus you obtain manually with
what the camera does automatically?

From the few photos I took with the Canon 60mm macro after installing the Katz Eye screen AF seems spot-on. I haven't had any AF problems in the past either. Of course I got the screen mainly for use with manual focus lenses like my Zeiss stuff (Y/C mount & M42) and the old Pentax Takumars.

-Dave-

 David Kieltyka's gear list:David Kieltyka's gear list
Leica M9-P Leica M8.2 Pentax 645D Pentax 645Z Panasonic Lumix DMC-GX8 +8 more
Jason Senior Member • Posts: 1,418
Fair enough, thanks for the answer.

Rachael,

Thanks for the straight answer. That's kind of what I figured. If for some reason the technology/materials do get cheaper, I'm all for it. I'm planning on skipping at least 2 maybe 3 generations of DSLRs if I can help it. The 10d is just perfect for what I need, except for the manual focus capability.

-- hide signature --

--Laws alone can not secure freedom of expression; in order that every man present his views without penalty there must be spirit of tolerance in the entire population.
--Albert Einstein

OP Doug Kerr Forum Pro • Posts: 20,898
I'm not sure what you;re asking (nt)
n/t
 Doug Kerr's gear list:Doug Kerr's gear list
Leica V-Lux 4
Keyboard shortcuts:
FForum MMy threads