Haoda/Katz Eye Focusing Screen...

[Khanh M]

I plan on purchasing one of these focusing screens in the near future and I am a little curious as to how it works in terms of AF.

If I understand correctly, in MF the part of the image in the inner circle (split prism?) of the focus screen needs to line up to achieve correct focus...

What happens to the same inner focus circle when you use AF?

If the AF is not perfect...I assume that I would still see the mis-aligned center...

If I had a lens that could MF full time (17-40L) could I AF and make minor adjustments (if needed) to get it perfect?

--
Regards,

Khanh M

http://www.pbase.com/khanh007
http://khanhmai.com

 

[Don Glenn]

I plan on purchasing one of these focusing screens in the near
future and I am a little curious as to how it works in terms of AF.

I don't have one, but I have thought about getting one for some time.

The focus screens can effect the metering, but no the AF. AF mechanism is below the mirror box, and gets its image source from a secondary mirror behind the primary mirror. The metering mechanism is above the mirror box, and above the focus screen.

If I understand correctly, in MF the part of the image in the inner
circle (split prism?) of the focus screen needs to line up to
achieve correct focus...

What happens to the same inner focus circle when you use AF?

Nothing. It will show as normal.

If the AF is not perfect...I assume that I would still see the
mis-aligned center...

Yes

If I had a lens that could MF full time (17-40L) could I AF and
make minor adjustments (if needed) to get it perfect?

Yes

--
Regards,

Khanh M

http://www.pbase.com/khanh007
http://khanhmai.com

 

[rachp]

I plan on purchasing one of these focusing screens in the near
future and I am a little curious as to how it works in terms of AF.

If I understand correctly, in MF the part of the image in the inner
circle (split prism?) of the focus screen needs to line up to
achieve correct focus...

What happens to the same inner focus circle when you use AF?

If the AF is not perfect...I assume that I would still see the
mis-aligned center...

If I had a lens that could MF full time (17-40L) could I AF and
make minor adjustments (if needed) to get it perfect?

--
Regards,

Khanh M

http://www.pbase.com/khanh007
http://khanhmai.com

I have the Katz Eye screen and love it. I do a lot of macro shooting and it is so much help. You are right on all of your points - you have a great understanding of how it works and how it will benefit you. When I got mine, it made it very easy to tell when the AF was even slightly off.
--
Rachel
CATS member #51 > ^..^
Hummingbird Hunter #6

 

[semorg]

I plan on purchasing one of these focusing screens in the near
future and I am a little curious as to how it works in terms of AF.

If I understand correctly, in MF the part of the image in the inner
circle (split prism?) of the focus screen needs to line up to
achieve correct focus...

What happens to the same inner focus circle when you use AF?

If the AF is not perfect...I assume that I would still see the
mis-aligned center...

If I had a lens that could MF full time (17-40L) could I AF and
make minor adjustments (if needed) to get it perfect?

--
Regards,

Khanh M

http://www.pbase.com/khanh007
http://khanhmai.com

I have Hoodas. And he was very fast delivering the screen. I do not know how it compares against Katz.

I am glad I put the screen on my 20D. It even helps when i am looking through my 500 lens and see if I am off or not.

As other memebers said all your points are correct.
--
My Latest Gallery: From Peru to Chile: http://www.pbase.com/salim/peruchile2005

 

[PpAeagle]

Ordered a Haoda split diagonal screen for the 20D, was convinced after reading some reports, have lots of Nikkor manual lenses and can't get a correct focus with the 20D, hope it help's...
--
1DMKIIn-20D
50mm F1.4 16-35mm L
24-70mm L 70-200mm IS USM L
100-400mm L 500mm F4 L
580EX Flash Tamrac 7755 Bag
Gitzo 1327 Tripod Arca Swiss B1 etc, etc...

 

[Khanh M]

--
Regards,

Khanh M

http://www.pbase.com/khanh007
http://khanhmai.com

 

[Walsh_uk]

I have one on my 10D and have never looked back.

say hello to tack sharp stills!!

Its a Haoda screen.

You lose the squares marking focus on the 10D

You can mod them to light up by marking the matt side with a soft pencil dot...Haodas yahoo forum says more on the subject.

Plus its a great way to check auto focus by observing the split line after auto focus is confirmed.

When using the centre focus area the split prism centre line still lights up red to confirm focus when in manual with a canon lens!

The best part about it all is the cheap (very cheap cost) lenses that can be picked up all over the place. For example the 55mm Super Takumar f1.4 for £15 mint! or a Zeiss 35mm f2.4 Flecktogon for similar

Fit a simple eos to M42 thread adapter and have alot of fun.

A lot of fun for little cash....

--
Walshy

 

[Walsh_uk]

In fact this shot was taken from my car window hand held with a Auto Chinon 200mm f3.5 @ f5.6

I paid ..... £1.20! yes... £1.20!! on an auction site for it. And have seen several not even getting a bid on them!

Enjoy those old manual lenses...



this is a 100% crop



--
Walshy

 

[Khanh M]

If the Haoda focusing screen blacks out (bottm half) by f5.6 or f6.3... then it cannot confirm focus anymore (manually)...ciorrect?

--
Regards,

Khanh M

http://www.pbase.com/khanh007
http://khanhmai.com

 

[T3]

If the Haoda focusing screen blacks out (bottm half) by f5.6 or
f6.3... then it cannot confirm focus anymore (manually)...ciorrect?

Yes. You need to be able to see both halves of the circle in order to see if their respective images line up. If you can only see half the circle (when it blacks out, only half the circle blacks out), then you can't see if they are aligned. But this has no effect on autofocus since autofocus doesn't use the viewfinder screen for focusing. It's also not an issue for manually focusing unless you have lenses that are at f/6.3 or smaller (like if you are using a f/5.6 lens with a teleconverter).

 

[RiverSide Photography]

is the only difference the blacking out at f/5.6 or greater apertures or there are other differences?

--
I see dead pixels

 

[Khanh M]

I will probably pay a litte extra and get the Katz Eye screen simply because I have the 400mm 5.6L, which I am not willing to part with or use less of....

Too bad it blacks out so soon... =(

--
Regards,

Khanh M

http://www.pbase.com/khanh007
http://khanhmai.com

 

[bronxbombers]

If the Haoda focusing screen blacks out (bottm half) by f5.6 or
f6.3... then it cannot confirm focus anymore (manually)...ciorrect?

true to some extent, but if you shift your eye a little and place it well, you can still focus with f5.6 lenses. it seems to work pretty naturally for me, however I have heard others say that they can't align their eyes well with f5/6 lenses and it is a nightmare for them to get it to work, so easy for me, but perhaps not for you, who knows.