How to focus better? Use of focusing screen?


Camelah

New Member
Aug 20, 2010
13
0
0
#1
Hi pro's,
I have been playing with my canon 40D now for 2+ years. Now and then I experience some tricky situations, and I'm thinking of buying a Ef-S focusing screen. But I'm not sure that this solves the problem, so here is my problem:
typically, I found I can rely on the autofocus. However, when shooting some head portrait of my young daughter with aperture wide open (2.8 to 1.4), the DOF is so shallow that proper focusing is utmost important.
I typically apply 2 methods: either just shoot ahead several shots and later select the best one, or use live view, magnify 10x, and focus manually.
Is there a better way?
I found the viewfinder only of little help at wide aperture. Is this just me?
Will the Ef-S be >>significantly<< better (value for money)?
I also saw some 3rd party split focus screens, with split opinions about usefulness.
Would split focus screen work on 40D, as the firmware does not have a specific setting for metering with it?
Thanks guys. I'm asking this since in my research, I did not find much info on the usability of focusing screens.
 

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Rashkae

Senior Member
Nov 28, 2005
19,105
12
0
#2
Why can't you focus accurately using the other focus points on the 40D?

That being said, the focusing screen will help in manual focusing through the viewfinder, but will be zero help in liveview mode.
 

daredevil123

Moderator
Staff member
Oct 25, 2005
21,644
63
48
lil red dot
#3
Focusing screen does not affect metering and do not need special settings.

I would look at focusingscreen.com, a company in Taiwan. Their screens are mostly cut from original Nikon or Canon screens meant for other cameras (mostly film). They also have a couple of ranges that are 3rd party manufactured.

You can also try KatzEye which are very expensive.
 

midicity

Senior Member
Mar 14, 2006
681
0
16
#4
Focusing screen does not affect metering and do not need special settings.

I would look at focusingscreen.com, a company in Taiwan. Their screens are mostly cut from original Nikon or Canon screens meant for other cameras (mostly film). They also have a couple of ranges that are 3rd party manufactured.

You can also try KatzEye which are very expensive.
Actually, some Focusing screens do affect metering. Eg EG-S.
You have to change settings in the camera to let it know you are using EG-S or metering will be off as it's darker than the standard focusing screen
 

Apr 7, 2010
2,560
0
0
Southern Enclave
#5
Focusing screen does not affect metering and do not need special settings.

I would look at focusingscreen.com, a company in Taiwan. Their screens are mostly cut from original Nikon or Canon screens meant for other cameras (mostly film). They also have a couple of ranges that are 3rd party manufactured.

You can also try KatzEye which are very expensive.
So I gather you've changed yours on your D300s? :D

I was contemplating changing mine, but I think I should wait until the warranty runs out... (this was suggested by a friend a month ago)...
 

Camelah

New Member
Aug 20, 2010
13
0
0
#6
Why can't you focus accurately using the other focus points on the 40D?
Please help me to understand your point. I mainly use the center point, true. So let us say I use aperture 1.4. And to eliminate body and camera movement, let us say I shoot a picture on the wall, using the center focus on one eye.
If I repeat this several times, I noticed that the camera will not produce 100% equal results, depending on where exactly I hit the eye, and how good it can focus on that particular spot.

That being said, the focusing screen will help in manual focusing through the viewfinder, but will be zero help in liveview mode.
So which one would you recommend, the Ef-S or a split prism screen? And is the difference significant enough to see it? Imagine you have a face in the viewfinder, and you want to notice whether the eye is really totally sharp, or whether there is a slight imperfection... an eye can be quite small on a viewfinder :-S

I also thought of a viewfinder magnifier. Would that help more compared to a Ef-S focusing screen? Or apply both? Just wondering whether anyone is using this and got good (or bad) experience.
 

Camelah

New Member
Aug 20, 2010
13
0
0
#7
Focusing screen does not affect metering and do not need special settings.
For Canon, the Ef-S is one of them that does affect metering, and the Camera provides settings for it to adjust, as the viewfinder (and the metering system) gets darker.

I would look at focusingscreen.com, a company in Taiwan. Their screens are mostly cut from original Nikon or Canon screens meant for other cameras (mostly film). They also have a couple of ranges that are 3rd party manufactured.

You can also try KatzEye which are very expensive.
Yes, I found earlier comments on the Katzeye. I also found a few China-made split focus screens as well. I'm just afraid (due to some comments in the web) that it might be too hard for me to adjust to this method, as so far I'm only using a plain screen (or formerly P&S LCD).

Also, since Canon 40D has these options for the three available Canon focusing screens but not for 3rd party, I'm afraid that the metering might be off, too.

So two reasons that keep me away from split focusing screens, unless I would find more supporting opinions in favor of such screens, particularly on 40D.
 

Anthony Lee

Senior Member
Feb 12, 2009
2,465
2
38
Shunfu Road, Singapore
#8
Hi pro's,
I have been playing with my canon 40D now for 2+ years. Now and then I experience some tricky situations, and I'm thinking of buying a Ef-S focusing screen. But I'm not sure that this solves the problem, so here is my problem:
typically, I found I can rely on the autofocus. However, when shooting some head portrait of my young daughter with aperture wide open (2.8 to 1.4), the DOF is so shallow that proper focusing is utmost important.
I typically apply 2 methods: either just shoot ahead several shots and later select the best one, or use live view, magnify 10x, and focus manually.
Is there a better way?
I found the viewfinder only of little help at wide aperture. Is this just me?
Will the Ef-S be >>significantly<< better (value for money)?
I also saw some 3rd party split focus screens, with split opinions about usefulness.
Would split focus screen work on 40D, as the firmware does not have a specific setting for metering with it?
Thanks guys. I'm asking this since in my research, I did not find much info on the usability of focusing screens.
If you are mainly using AF lenses with constant aperture f2.8, you can use the Canon Ef-S focusing screen to improve your view through the VF as the Ef-S focusing screen is a super precision matte screen and provides better contrast. Also google "focus shift" and understand how this can cause certain F1.2 or F1.4 lenses from suffering from such effect and how you can handle them better. There is no necessity in using split focusing screen unless you intend to do alot of manual focusing, especially with manual focusing lenses.
 

Camelah

New Member
Aug 20, 2010
13
0
0
#9
If you are mainly using AF lenses with constant aperture f2.8, you can use the Canon Ef-S focusing screen to ...
Yes indeed, I am, except the Sigma 50 f1.4. Had Canon 50 1.8 and 1.4 before but found the AF are a lot more unreliable. And I prefer the Sigma Bokeh, too.

Also google "focus shift" and understand how this can cause certain F1.2 or F1.4 lenses from suffering from such effect and how you can handle them better.
Thank you a lot for this advise. This is the first time I find mention of this. I will surely investigate it.

There is no necessity in using split focusing screen unless you intend to do alot of manual focusing, especially with manual focusing lenses.
No, not a lot. Only in exceptional cases. Also another reason why I would prefer not to use a split focusing screen.
 

Camelah

New Member
Aug 20, 2010
13
0
0
#10
Also google "focus shift" and understand how this can cause certain F1.2 or F1.4 lenses from suffering from such effect and how you can handle them better.
Wow, this explains a lot (but not the specific problem I was mentioning above, focusing on the same spot without recomposing).
To share with others, here is a great site that explains the focus shift when recomposing:
http://visual-vacations.com/Photography/focus-recompose_sucks.htm

I was not aware of this, but it will probably explain some of the focus errors that I experienced earlier, as I enjoy shooting wide open.

Also, finally makes me understand why there is more than just one (center) AF sensor. I found recomposing easier than selecting another AF sensor.

I'm now glad that I asked the question. In fact, I thought: "why not just buy it, it's only 50 bucks". Had I done it, I would not have learned!

I will read up more on focus shift; it appears that recomposing is not the only source for this phenomenon.

Thanks again to all that contributed here!
 

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ovaltinemilo

Senior Member
Sep 12, 2009
2,819
0
0
Sin jia Po lah
#11
Actually, some Focusing screens do affect metering. Eg EG-S.
You have to change settings in the camera to let it know you are using EG-S or metering will be off as it's darker than the standard focusing screen
my focusing screen affects spot meter...not so on matrix metering...probably due to the darker split prism..

anyway, split prism has it's short coming too since the split is only in the middle...focus and recompose using wide f1.4 etc will still give a prob...it's better to choose af point in this kinda case...

most likely AF is accurate if lens is not experiencing focusing prob...
 

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cichlid

Senior Member
Dec 2, 2006
5,066
3
38
S'pore
#12
Hi all

I found some viewfinder magnifyer at our Mass Sale here, does it help?
 

Anthony Lee

Senior Member
Feb 12, 2009
2,465
2
38
Shunfu Road, Singapore
#14
Wow, this explains a lot (but not the specific problem I was mentioning above, focusing on the same spot without recomposing).
To share with others, here is a great site that explains the focus shift when recomposing:
http://visual-vacations.com/Photography/focus-recompose_sucks.htm

I was not aware of this, but it will probably explain some of the focus errors that I experienced earlier, as I enjoy shooting wide open.

Also, finally makes me understand why there is more than just one (center) AF sensor. I found recomposing easier than selecting another AF sensor.

I'm now glad that I asked the question. In fact, I thought: "why not just buy it, it's only 50 bucks". Had I done it, I would not have learned!

I will read up more on focus shift; it appears that recomposing is not the only source for this phenomenon.

Thanks again to all that contributed here!
You should also read "spherical aberration".

This is also good. http://diglloyd.com/articles/Focus/FocusShift.html
 

pinholecam

Moderator
Staff member
Jul 23, 2007
10,925
84
48
#15
Hi all

I found some viewfinder magnifyer at our Mass Sale here, does it help?
It does. To me it does more than a split screen. The drawback is that they are limited to 1.2 to 1.3x mag. Any larger and some of the viewfinder will be cropped off (need to move the eye around to see).
 

cichlid

Senior Member
Dec 2, 2006
5,066
3
38
S'pore
#16
It does. To me it does more than a split screen. The drawback is that they are limited to 1.2 to 1.3x mag. Any larger and some of the viewfinder will be cropped off (need to move the eye around to see).
Ok, thanks. I was thinking to fix a magnifyer for macro shooting....
 

Rashkae

Senior Member
Nov 28, 2005
19,105
12
0
#17
Please help me to understand your point. I mainly use the center point, true. So let us say I use aperture 1.4. And to eliminate body and camera movement, let us say I shoot a picture on the wall, using the center focus on one eye.
If I repeat this several times, I noticed that the camera will not produce 100% equal results, depending on where exactly I hit the eye, and how good it can focus on that particular spot.
I use all focus points, and usually shoot with an f/1.8 lens. It's almost always focused where I told it to. :)

So which one would you recommend, the Ef-S or a split prism screen?
In your case, EF-S. But you also need to note that proper handling and learning how to use all focus points is important too, even if the 40D's AF is notoriously inaccurate.
 

Camelah

New Member
Aug 20, 2010
13
0
0
#19
Just want to update you all:
I finally bought the Ef-S focusing screen last Wednesday. After my initial testing, I thought I wouldn't notice a difference at all.
Today I took a lot more pictures with my sigma 50 f1.4, and By now I am totally amazed.
For me, I can say it was worth the 50$. I can manually focus at f1.4, and will be right on spot. It is amazing. I can really notice a significant improvement. With the original screen, I often missed the spot at wide apertures, unless I used live view and magnifier. But with the new focusing screen, it appears as if you can see the shallow depth of field right in your viewfinder! You can see exactly where you focus. I took many shots, and almost all were right on target.
So thumbs up...
 

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