Split focus screens, ie: Katzeye, etc.

[Rocco Penny]

I have a Katzeye split focus screen I've been using pretty successfully.
I do find it helpful in very static shooting conditions, but have always been able to take the time for critical focus when I use it.
In low light and with my 600mm f/5.6 MF it becomes a burden sometimes.
Specifically when I'm trying to make an exposure of an animated target, or in low light, or generally speaking, at anytime I don't really just take the time to
get the most out of my split screen,
the exposures are muddy.
Simple as that.
No focus, no Star, no F#*% (Thank you Brautigan)
So my muddy exposures depend on my critical focus through a split focus screen that although a real help in static situations, is a hindrance to me while shooting moving subjects or in low light.
I'm sure the aperture causes limitations, but specifically,
should I replace the brand new focus sreen with a katzeye considering the warranty period is coming to a close anyway.
Alternately,
would you just wait and see the % of critically focused exposures using the OEM screen?
It may seem a silly thought, but if I get the same percentage of good exposures using either,
I'd rather use the OEM because it is easier to really see the whole shot in that perspective.
IDK
I just don't want to replace it if I am going to get the same %
OK thank you all for the space,
and learning everyday
RP

[marcmccalmont]

When you say "muddy" do you mean slightly out of focus?
what camera?
Marc

[Rocco Penny]

Hi thank you for the response,
I hope I'm not in the wrong forum,
Nikon D300 using manual focus, aperture priority, usually f/8 usually PRESET color with a graycard on location
ISO 200 to 800 usually gets me to a speed I can use with the 1.5 crop sensor ON A TRIPOD-
Mirror up and 30 second delay for static shots
The minute I deviate from the above described condition, I get slightly out of focus exposures.
Not every exposure, just many or most even depending on how good the day went.
I can get pretty good exposures when very deliberate and concentrated.
Even a moments distraction can throw the whole thing into big smears of color.
Well not that bad, but I have many images of wildlife I try to capture cleanly that generally look crappy
I want to up my percentage.
I will try without the split focus screen for a while.
See what happens.
Won't know if I don't try.
I've answered my own question with your help,
thanks

[marcmccalmont]

Is it in autofocus that it's not sharp?
Is it manually focusing handheld?
Is it manually focusing on a tripod?
When on a tripod focusing with liveview (100%) bypasses all the miss alignments with your mirror/focusing screen/prism etc
I have great luck manually focusing either a Katzeye or a Maxwell precision optics screen, both are good but Bill Maxwell will custom make them to your needs
put a texture on the surface based upon the maximum aperture of your most used lenses and vacuum anneal them for flatness since all factory screens are a bit "potato chipped"
On a tripod, MLU, cable release and hanging a backpack on the hook (mass damping) will all help
If auto focus is the problem, My Canon 5DII allows micro adjustments for autofocus with each lens (I use a lens align lite)  My Mamiya/Phase One DF does not so factory alignments/adjustments are more critical. Another thought is have you analyzed your exif data after the fact to see if you are using too slow a shutter speed for your shot?
If manually focusing without a split screen I use a military technique for getting artillery on target (not needed today with guided munitions) Over, Under, On. Focus until blurred in one direction focus until blurred in the other direction then set the focusing ring in the middle of the 2 by feel. I get almost 100% accuracy with the Mamiya and do a better job than autofocus most of the time.
When I get a new lens I test all apertures to see which is sharpest. Most of my Canons are around f8/f9, most of my Mamiya's are around f9/f11 (I need to retest this with the IQ180 because it could be diffraction limits due to pixel size?)  and my Rodenstocks are f8
So I would use f8, MLU, manual focus using OUO or liveview, use a cable release and hang a backpack on the tripod hook, for shorter lenses one hand on top of the mirror box/prism helps for long lenses a bag full of rice over the top of the lens. There is vibration somewhere in your out of focus shots or miss-focusing somewhere in your workflow. 
Marc

[Rocco Penny]

Thank you Marc,
mounted on a gitzo 1325 tripod,
all manual settings,
shutter speed between 1/80 and 1/1200 usually
I know the slow shutter speed doesn't help,
but neither does ISO 1600
So I usually want 1/800 second at ISO 200 and f/8
Hard to achieve in natural light and while moving the thing around to capture angles and light
I don't have a cable release.
Will this help?
I thought a 30 second delay in MuP would negate the need for one.
I know it sounds crazy long to get a few images, but I can easily shoot all day w/o fatigue
So,
yes I think maybe some vibration is happening.
I use a Kirk BH1 and don't think that is the problem.
I wonder if getting a nice heavy beanbag for the top of my lens would solve some of my problem

[ErikKaffehr]

Hi,

I'm not on Nikon but I'd say that live view with highest magnification is the only option. I have a Sony Alpha 55SLT (with non moving mirror) that I use with 400 mm + 2x extender and have neither problems with vibration nor focus, except the 400/4.5 is not made for manual focus. The lens/extender combo is nit very sharp, but 400/4.5 + 1.4 extender can achieve critical sharpness in the center. So I'd say that Live View, nonmoving mirror and self timer works for me. I use either a Gitzo GT3541LS or a Velbon Sherpa Pro 630, with an Arca Swiss D4 head.

Best regards
Erik

Thank you Marc,
mounted on a gitzo 1325 tripod,
all manual settings,
shutter speed between 1/80 and 1/1200 usually
I know the slow shutter speed doesn't help,
but neither does ISO 1600
So I usually want 1/800 second at ISO 200 and f/8
Hard to achieve in natural light and while moving the thing around to capture angles and light
I don't have a cable release.
Will this help?
I thought a 30 second delay in MuP would negate the need for one.
I know it sounds crazy long to get a few images, but I can easily shoot all day w/o fatigue
So,
yes I think maybe some vibration is happening.
I use a Kirk BH1 and don't think that is the problem.
I wonder if getting a nice heavy beanbag for the top of my lens would solve some of my problem

[marcmccalmont]

Don't forget hanging a backpack from your tripod that makes a big difference!!
I will no longer buy a tripod without a hook!
Marc

[Rocco Penny]

Hi again,
I have lightened my grip and backpack to the point they're only a couple pounds without gear.
I sometimes take a tin of peaches or the sort of thing-  I can tell the difference right away.
40 pounds is much less than 50 or 60 when you walk long distance.
I go less than 10, more than 5 whenever I shoot usually,
sometimes it is impossible to hang the backpack because of tripod height(low shooting obstacles etc)
Besides, sometimes the backpack would be in danger of getting dirty.
I am pretty fussy about dirt in my gak
I think of Jack LaLane's rubber thong exerciser.
Remember the one that housewives were to slip over doorknobs to keep in shape,
and that made for fearsome weapons fallen into the wrong hands?
One of those slipped around my lens on one end,
and taut to the ground with ??ummm??
So in other words,
I'd rather not haul more heavy stuff.
Considering ways to lighten the load actually-
If Thunderpooch could just carry something!
That darn tripod/ballhead combo is heavy as well as bulky.
I was reading the recent tripod review on the main page, that thing looks perfect for me.
Even shooting resting the outfit on a large beanbag (10"x24"beanbag) yields too many
OOF exposures.
I can make perfect exposures some small percentage of the time.
I mostly like my impressionist view of nature anyway, and don't necessarily want to take shots as perfectly rendered as with say D. Oakes Or Mr. Fisher
I like my own way,
But and the big darn but,
is that simply stated, I get at least 50% OOF exposures when I want them to be perfectly focused.
You see?
So really I have some wonderful snapshots of my many adventures, but when I'm trying to make that one darned good exposure entirely focused, I'll miss at least half the time.
So I have stalked for instance a particular butterfly in a large farmyard, and taken hours to try and capture the thing on a particular flower it was on yesterday.
Take my time,
butterfly shows up,
I miss 50% of the shots.
I'd like to get more focused shots-
Not sure if the katzeye helps or hinders my shooting style.
I suppose if I was good yet I'd know right away.
Remember I'm still working out the fundamentals of making the shots possible.
So the execution of the exposures is my real weakness.
I find terrific subjects and just blow it half the time.
I want to rule out my camera support as a cause of vibration
Tethering the lens to the ground would help absolutely, no?
Thank you and forgive the ramble