View Full Version : Improvement: Manual Focusing Screen

04-22-2008, 08:41 PM
I went ahead and had a Katz-Eye™ manual focusing screen added to the α700


so I could make optimal use of my various TAMRON Adaptall 2 MF lenses (135 f/2.5; 200mm f/3.5; 70-200mm f/4; 200-500mm f/6.9)

That 135mm f/2.5 seems to be a super lens ... and I am interested to see how improved the quick focusing will be.

SONY α100 w/ TAMRON Adaptall 2 135mm f/2.5 lens

Unfortunately, the closest focus this particular lens can do is just under four feet, but it should make for a decent portrait lens though.

Anyway, the camera is on the return trip from Maine, where the Katz-Eye™ was installed. I am anxious to get it back and see the results. Allthough I could obtain a sharp enough focus after a few shots, with the DSLR, my eyes just don't have the twenty-year-old's acuity any more. Yes, you guys, we all get old. Just you wait ... you little whippersnappers! I am pretty certain this will tighten things up a bit ... and I'll be able to seriously use this older glass, which is still sharp as heck ... a bit more successfully.

04-22-2008, 09:54 PM
i put one in my old a100...fit like crap though...
but i got it lined up...didn't like it though..so i took it back out:rolleyes:

04-23-2008, 06:51 AM
Well ... they are insisting on doing the fitting for the customer, so let's see, eh?

04-23-2008, 07:41 AM
"they are insisting on doing the fitting for the customer"...lol.i know why. it fits so loose you have to carefully center it...the problem that i didn't like most was it would go black in low light situations...i forgot about that since my sr101 days

04-23-2008, 09:45 AM
I had the OptiBright Treatment also added ... which Katz-Eye details as this:

"Although the Katz Eye™ focusing screens look good and they are bright as they are, if you want the ultimate appearance they can be treated to improve their brightness. We provide a process called OptiBrite which is designed to improve the brightness of our screens at small apertures or in dim light. The treatment can increase the apparent brightness by about 2 stops or more in some conditions. The extra brightness is difficult to quantify exactly due to the subjective nature of human vision, but it tends to increase with smaller aperture. At f1.4, for example, the OptiBrite treatment provides only a moderate improvement — perhaps ˝ f–stop equivalent or less. But, as the aperture gets smaller, the improvement gets greater. By f6.3, it's good for about 1 full stop. By f16, it might be equivalent to 2 stops or more, depending on the conditions. It's definitely a pleasant change. For the record though, OptiBrite will not affect the ‘blackout’ phenomenon, where half the prism(s) turn black around f5.6 or so. The OptiBrite treatment only affects the brightness of the matte (ground glass) portions of the screen. If you need small aperture performance below f5.6, our Katz Eye™ “Plus” series of focusing screens will allow split prism performance well past f11. More information on the “Plus” screens can be found here. Please be aware that in most cases, the OptiBrite treatement does not change the light metering significantly. However, in some cameras the increased brightness of the focusing screen resulting from the OptiBrite treatment may slgithly affect the camera's light meter. In cameras that are affected by the treatment, the effect is usually minimal – OptiBrite treatment will typically cause no more than a 1/3 EV shift of the light meter. With DSLR's, it is a simple matter to take a quick test shot, check the histogram, and adjust your exposure compensation as required to ensure that you achieve proper exposures. The OptiBrite treatment costs an additional $55USD on all Katz Eye™ Screens."

So I guess we shall see what we shall see ...

04-23-2008, 11:59 AM
Then Are Your Eyes Good Enough To See Things Line Up...lol

04-23-2008, 08:11 PM
Then Are Your Eyes Good Enough To See Things Line Up...lol

Probably not ...


Although, I did also add this:


“Rule of Thirds” Grid

This commonly requested pattern can be very helpful for composition based on the "Rule of Thirds".

I tend to already practice it ...


but, I figure it is a good reminder.

04-25-2008, 09:38 PM
Halleluiah, the α700 is back!

α700 Katz Eye™ installed:

Okay ... I did initially notice that focusing, with normal lighting, is tremendously improved. As I dimmed the lights, it got to be more difficult.

As I closed down the aperture, again, more difficult to focus. I found that focusing at the widest aperture and then immediately adjusting the aperture to what you want seems to solve that issue. Technique and procedure, that's all.

It definitely improves the performance of the AF lenses (135mm f/2.5, 200mm f/3.5, 70-200mm f/4.5, 500mm f/8 Reflex and 200-500mm f/6.9).

If the weather clears up, tomorrow ... I may just head for the lake (Lake Michigan) have a manual lens day ... just for the fun of it. See if I can improve my DRO experiences along the way, also.

Is it worth it? Hard to say, at this point ... but, it does speed up my manual focusing, enormously. That's definitely improved and worth something. I have five lenses that have suddenly improved in performance and usefullness.

Autofocus ... okay, here's a spot of trouble with α700. The α700 has three focusing modes: WIDE, SPOT & LOCAL (Camera defaults to WIDE, when in the AUTO). "Wide" and "Spot" seem to work fine ... "Local" control ... if you select anything other than center ... I think it's kind of lost, which effectively has killed it. Personally, I have never use "Local" ... so I don't suffer with its loss, but I am sure there are others, out there, who might resent losing it.

Anyway ... that's it for now

04-26-2008, 09:05 PM
did you get snow today?..lol...winter just won't quit in mn

04-26-2008, 11:09 PM
Nah ... actually ... the rains dried up, around 10AM .. and it was windy as heck, but nothing too serious. Amazing weather this year ... thank goodness nothing ever came of that "Global Thingy", eh?

04-28-2008, 09:11 AM
Well, after several images and trials, I have to admit ... the Manual Focusing screen seems to be quite useful compared to the naked-eye. No matter how I can recall it, this split screen has gotten me closer than any other method I have used on the digital SLR ... so I feel it has been a worthwhile investment.

I liken it to using bifocals ... if you don't need them and are using AF on your camera, most of the time, don't bother. But if you do manually focus ... it can be a heck of an assist.

Speaking of which, I have not really noticed much impact to the autofocus system ... it seems to work without any detrimental effect. YMMV.

I need to use it with the two MACRO lenses (90mm & 180mm) I have to get the overall feel for it, but without a doubt ... practical use of the manual lenses is, once again, back.

11-25-2008, 01:58 PM
I do appreciate TAMRON ceasing their support of their own Adaptall2 prduct line on SONY, Canon, Nikon and Pentax camera bodies, by discontinuing the Adaptall2 adapter collar. "Appreciate" in the sense that these lenses simply cannot provide a sharp enough resolution without the aid of an addition MF focusing screen. I believe our eyes (perhaps just mine ... and I felt I was pretty good at that) just are not that great at picking up the visual cues better than the digital sensor can.

Even with the MF focusing screen, it is a still struggle. Also, the these older lenses do NOT have the coatings and treatments necessary to be competative with today's standards in lenses. Color aberration (CA) and purple fringe run amok with them and based on comparative shots that I have done ... well, let's just say that I have gone ahead and methodically replaced ALL of my Adaptall2 lenses (135, 200, 70-210, 200-500), in one way or another, with digital AF types ... basically all of them with TAMRON, except for the SONY CZ 135mm f/1.8.


I still keep these manual lenses for use on the film bodies, but when it comes to use on the digital ... overall, it's just been a bust. :( C'est la vie!

As far as the MF focusing screen goes, it has been an excellent tool, for use with AF glass, when I could not obtain focus "automagically", such as shooting through weeds, tree branches or other interference, like screens and windows. If you routinely find your self in manual focus, or using DMF, I highly recommend having it, but you need to be aware that it offers small challenges, too, when it gets darker. :cool:

11-27-2008, 11:25 PM
I wonder if I could get the rule of thirds grid on my contacts LOL I had read about Katzeyes when researching my camera, just way to much other stuff to learn how to do and use before I start adding things I guess. And speaking of eyes and age yea it sucks! I have been wearing 'zoned' contacts for about 3 years now, pretty handy, but the dilema, I am left eye dominate, rather near sighted, have better far vision in left eye then right, slight to moderate astigmatizm in both eyes, more in the right. contacts are adjusted for close and midrange vision in right eye, midrange and far in the left. I have even thought about trying to learn to shoot with my left eye? Life is the adventure, but it's the getting old that blows!