Focus screens

[Fruengalli]

I just picked up a fully manual lens (no focus confirmation) for my 5dii & was wondering if anyone had any experience with the split or other types of focus screen options.

[ameerat42]

F. I don't know exactly what you mean by "no focus confirmation". Do you mean no AF? Are you then linking this to
the question of whether a split-image focus screen would help? Assuming that this is what you mean, then I can only
relate some distant past stuff.

The split image is useful in cases where you have clear edges - perpendicular to the split - to work on. It slows down focusing
a bit, esp when there are none. I had a screen that had split-image centre, surrounding coarse ?"fresnel" zone, and outer normal
smooth focus zone. I tended to use all three.

Am.

[Fruengalli]

That's exactly what I meant. If i use my current lenses in manual focus I get confirmation in the viewer of correct focus but this lens (Samyang 14) has no electronics at all & so focusing is somewhat hit & miss. Apparently various screen options can be fitted for manual focus so just looking for some opinions. Yes hyperfocus & infinity focus work for the larger scheme but not at closer focal distances.

[ameerat42]

OK, ta. On my present camera I have only a clear screen with an array of focus points as little squares.

On this with manual lenses I have just twisted back and forth a bit (it's slow!) till it seemed sharpest.
Mostly, it worked.

[arthurking83]

I would have immediately recommended Katzeye as the preferred option, but they recently had some issues(personal, not business wise!), and have no closed their operation. So as an option(and I think the best) they no longer exist.

The other option is one from Focusingscreen.com (http://www.focusingscreen.com/index.php?currency=AUD&cPath=21_134)
Their screens work well, and give a much better manual focusing experience than a standard focus matte does(for faster lenses).

FWIW: I got a katzeye screen for my D300, and a focuscreendotcom screen for my D800.

The screen I got for the D800 is the super precision matte option(which is basically a Canon screen made to fit the D800) .. but no focus aid options on this one.
One day again, I may try one of their other options too, but I'm in no rush to do so.

Issue with the super precision matte (on the D800):
While the screen works great with lenses f/2 or faster(ie. f/1.8 or f/1.2 .. etc) .. with an F/2.8 lens there is considerable darkening of the view through the viewfinder.
So, as I predominantly use f/2.8 lenses(although AF types) .. overall the D800's screen is darker now than it used to be (with the std screen) for most of my photography.
But when I mount one of my generally faster manual lenses, it's not an issue at all. I don't have many slower than f/2 manual lenses that I use handheld. Those that I do have I usually use them with Lv mode(usually macro).

So for example, if I mount the 105/1.8, the vf is nice and bright. If I set it to f/2.8 tho, and use the DOFP button to stop the lens down, there is a shift in brightness that is noticeable.

To see this amount of shift, mount any of your lenses you currently have now, set it to about f/8 and press the DOF Preview button(I assume the 5D has this feature). You will see some darkening of the view.
The less light there is, the more obvious the darkening effect.

If I set any lens to f/5.6 or say f/8, and use the DOFP the vf is very dark .. more like you will see with a std screen and DOFP at say f/11-f/16.

On the D800 this is only a really big issue when I mount the 500/8 .. which is f/8 of course.
In low light the lens is close to unusable. Strangely tho I can still focus quite accurately .. as long as the subject matter has lots of contrast to separate it from the rest of the scene.

The reason I mentioned the Katzeye screen, is that there are ways to make screens both super precise in manual focusing, AND bright. Even tho the D300's viewfinder is a bit darker than the D800's in std form, with the katzeye screen in the D300, the brightness difference advantage it has is massive compared to the D800 with focusingscreen screen.
I just hope that one day soon, someone else will pick up where Katzeye had to leave it.

Remember this darkening effect is only when slower lenses are used, and (going with what I have) on the focusingscreen's super precision screen. I don't have any experience with FS's other screens to make comments.

But, if I had the option to do it all again, I'd still take the super precision version of FS's screen again. Like I said tho, one day I'll end up trying one of their other screens too.
The reason I'd still use the super precision matte, is the ability to hit focus spot on more often than not with fast lenses.

I can't remember the exact results as I did the tests a few years back now and all relevant images were deleted as not very important images in my archive, but I have a vague recollection that I may have hit 1 in 10 attempts using the 105/1.8 lens at close to minimum focus distance and wide open.
That sort of hit ration implies that the one shot I nailed focus on with such a narrow sliver of DOF, was probably a complete fluke, and/or more of an educated guess as to where actual focus was.

I know that I have had a hit rate of 7/10 with the FS super precision screen tho. (every now and then I do a retest to keep myself in practise with manual focusing this lens)
Note that even tho my 50/1.2 has the faster aperture, the 105/1.8 is the harder of the two to focus accurately at MFD as the DOF is narrower.(or at least it appears to be).
According to DOF calculator, the 50/1.2 has the narrower DOF, but I've always found the 105/1.8 to 'feel' more difficult to focus at MFD wide open.

Anyhow, the point is that with the super precision screen, I can 'confidently' focus the 105/1.8, where with the std screen, I know I'd simply be guessing at most useful focus distances.
Of course there are other issues that compound misfocus or blur in an image, and the longer focal length is one of those issues.
(my comparison tests were done on tripod with MLU and all that stuff, to be sure that camera support wasn't an issue in any blurriness in the resulting images).

Focusingscreens products are very reasonably priced(by comparison to the katzeye at least!!) at about AUD$100-ish. Of course this goes up or down according to AU-US currency rate.
For a good example of the types of screen he offers, there is a link in the lower left showing the types of screens he offers too.
So in the link I set out, it shows you the models of screens available for the 5DIII. To see what those screens actually are, open a new tab of the screen comparison page he has.

The S-Type is the super precision one I have fitted to the D800. no focus aids.
If you check the Ec-L, is has a more precise matte screen(that is the overall screen) than the std AF screen uses, and has a 4 way split prism in the centre.
I'd expect with this type of screen, the precision matte(as opposed to the super precision matte I have) may not darken as much with f/2.8 or slower lenses.
The focus aids are great when(if!!) they work, but I found not as useful as you'd think they are.

The issue is, of course that it's rare to use always have the subject matter (that counts) in the centre of the frame!!

With the Katzeye screen I got it with all the bells and whistles. Split screen AND micro prism collar around the split screen.
Makes a very large area to 'focus on'. Note that the micro prisms works well too, as a main focusing aid too.
Why I got it on the Katzeye was that they advertised it as not having a blackout issue until very small apertures.
This I can confirm too. On the D300, on some lenses, I can confirm that their split screen doesn't blackout easily, and as the 500/8 was foremost on my mind at that point in time, I thought it'd be a good option to have.
I've set lenses to f/22 and not seen blackout on this screen. but some have caused the split screen blackout at about f/11(the fastest aperture I've seen) where blackout occurs.
So it made sense to get the split screen, and for the 500/8(which starts at f/8 and ends at f/8!! :p) it was a natural choice.

But I found that using the two lenses I preferred to use manually(the 50/1.2 and 105/1.8), I hardly ever tried to focus on any subject centred in the frame. They were almost always off centre.
So when the (really hard) decision came to get the screen for the D800, I ummed and ahhed for a long time. In the end the super precise overall matte screen was what I thought was best.
Even tho I expected darkening of the overall vf image, I didn't think it'd be so much on an f/2.8 lens.

Also, focusingscreen don't advertise any advantageous feature in their split screen aids either. So expect split screen blackout at about f/5.6 or so .. maybe f/8 if you're lucky.
This was the most important reasoning as to why I didn't get a screen with any focus aids.
The lens that NEEDS it the most(being the 500/8)... is simply too slow at f/8 to take advantage of the option.

So take that into account when(if) making the decision. If the Samyang has no electronics, which also assumes no aperture control(from the camera) .. which in turn means manual stop down too, then you could run into issues.
That is, if the lens has the issue of focus shift(unlikely) and you have to focus at f/8 to get focus accuracy, then almost certainly the split screen will be of little use due to the problem of blackout.(that is it simply turns black, and you can't see anything through it).
As long as focus shift is not an issue, you could of course set focus at the widest aperture and then stop down only for the exposure.


Sorry for the long post, and even more importantly, sorry if I've made your choice even more confusing too! :D


The other point to consider is this (http://www.leitax.com/Leica-lens-for-Canon-cameras.html):
That's a link to a Dandelion chip for Canon.
I don't know if you know what these things do, but in brief(as this post has already gone from a 'bit of info', to 'arduous diatribe' :D):
You stick this on the lens, and it turns it into a CPU'ed lens.
It needs to be programmed, which is easy .. all info is there on that page.

Those dandelion chips are also available on ebay(I've had both types for my Nikons).
Exactly the same products .. the Nikon ones easily break. These Canon types don't look as fragile tho.
programming is easy to do too via the camera. Ebay is cheaper.

Note tho: Nikon cameras always give you manual focus confirm, no matter the lens.
In my experience focus confirm is less accurate than a good visual confirmation of focus.
With the D300 and 105/1.8, I hit focus 10/10 times with the katzeye screen. going back to the std screen and relying on focus confirmation indication is hit or miss.
The issue (whether for me, or for my gear setup or overall.. I don't know) but if I focus from one direction on the lens(say from MFD) I can hit focus 9 or 10 out of 10.
But if I focus from the other direction(say infinity), then focus confirmation is always out.
That is, the DOF indication of focus confirmation has too much play in the system to be accurately accurate in some situations.
In saying that tho, in most situations a 14mm lens used in most normal situations, there would be enough DOF in the scene where any tolerances in the DOF wouldn't be a factor.


Hope that helps .. sorry for the long post.

[bushbikie]

Apparently various screen options can be fitted for manual focus so just looking for some opinions. Yes hyperfocus & infinity focus work for the larger scheme but not at closer focal distances.

Any reason why using LiveView would not help?

[arthurking83]

Liveview works well in some situations, but not all.

[Fruengalli]

Thanks Arthur for the bit of info. For the amount of time I will need close manual focus I think the negatives outweigh the positives for when I go back to my other lenses & as Bush bikie says there is always Live View.

- - - Updated - - -

Live view is OK sometimes & is looking like the option I'm stuck with.

[arthurking83]

Happy to help.

The issue with f/2.8 lenses is 'workable' .. in that while there is obvious darkening, even in night photography you can still see well enough to compose a shot.
AF isn't affected in any way tho.
With an f/4 lens, the issue may be significant enough to be a problem.
Trying to use the Sigma 12-24 f/4.5 - 5.6 can be a bit of a pain in some conditions with this matte screen mounted.
Although I say that without any experience of that lens with the std screen fitted to see how much light loss there is. I've only seen that with other variable aperture lenses of similar speed.

if I do relent soon, rather than later, and try another screen type from FS, I'll post again if there is enough improvement in those other screens.

The other thing I forgot to mention about split screen focus aids is that they apparently also affect some metering modes(mainly spot and/or centre weighted).
I can't really say that I've noticed this on the D300 myself, especially considering I use spot metering 99.9% of the time.

[dodgyexposure]

Hi,

I have a 6D and some manual focus lenses (including the Samyang 14/2.8). My approach to using the 14/2.8 is different to using my other MF lenses, so I'll start with the general MF comments.

Your 5D2 and my 6D can both use a Canon Eg-S super precision matte focus screen which aids in manual focussing. The Eg-S screen costs about $40, and makes manual focussing through the viewfinder feasible - areas in focus are much better differentiated in the viewfinder than OOF areas. The process to swap focussing screens takes about 2 minutes, and is straightforward. I find manual focussing thorugh the viewfinder hit and miss with the default EG-A screen, but enjoyable with the Eg-S screen.

On my camera, there is a custom function to tell the camera that I am using the Eg-S screen, rather than the default Eg-A screen, and this is meant to make any adjustments to focussing and metering that may be required. In my experience, AF and metering have not been affected by using te Eg-S screen.

What does change, as mentioned by another poster above, is the viewfinder will be noticeably darker for lenses with a maximum aperture narrower than f2.8. You can still see through the viewfinder to frame a shot, but the effect is sufficiently noticeable that I usually swap back to the Eg-A screen if I'm going to specifically use my 100-400.

Now, the Samyang 14mm/2.8. If I'm using it on a tripod (astro or landscape), then I just focus using liveview.

For handheld, I use zone focussing. This lens is so wide that the hyperfocal distance is very large. My experimentation indicated that focussing at 0.8m at f8 means that (practically) the entire scene is in focus, so if I am using the lens while walking around I tend to set the focus distance to 0.8 and just fire away. Close ups require an adjustment, obviously. Hyperfocal focussing at f8 works for me with this lens - this wide, there is very little separation to be had from using a wider aperture.

As to the AF confirmation beep/light, I honestly can't remember whether it even works with the 14mm. I have tried using AF confirmation with other manual focus lenses, and found it so unreliable that I never bothered with it again.

[andi]

Not sure if it's okay to post in another members thread, or if I should create my own - so I'll just ask here first.

I've got a EG-S screen for my 6D and when I use it with an F1.8 or F2 aperture I can never focus correctly via the viewfinder? I've take several pair shots (MF through viewfinder & lens AF) to compare: and the lens AF is also spot on.

The weird thing is that when the AF is spot on, what I see in the VF seems OOF to my eye?

Is there any explanation for this? I have also set the CF setting on the 6D to EG-S screen.

[ameerat42]

Andy.
Your post is borderline between adding to this thread and asking for help. As there's some relevance to the topic I will leave it here.
If you want actual help, though, put the post into General Help (http://www.ausphotography.net.au/forum/forumdisplay.php?21-General-Help).
Am.

[Gazza]

The weird thing is that when the AF is spot on, what I see in the VF seems OOF to my eye?

Gi'day andi, you could start here and adjust your 'Diopter' ... :url: (https://www.youtube.com/watch?v=R9JurnY4PC4) ... That should help with the OOF VF.

Hope that helps and sends you in the right direction? - Cheers - :beer_mug:

[arthurking83]

Yeah, my initial reaction to andi's reply is to be 100% sure that the dioptre is adjusted.

If your dioptre is adjusted well then hopefully the following can help somewhat:

Don't be disappointed that your eyes aren't as good as the cameras phase detection system in determining contrast to a high degree!
The focal length and focus distance will also have an impact on how accurate your manual focusing is going to be(ie. DOF)

If your f/1.8 lens is 105mm and you're focusing at 1m, then DOF is only a few mm deep so the precision(or possible lack of) from your eyes may be fooling you a little.
Also, assuming that you are doing this handheld ... in the time you have 'focused' and then exposed, are you 101% sure that you haven't moved fore/aft of the distance to the subject?

ie. are you doing your testing with the camera on a tripod or are you testing handheld?

For the purpose of testing the screen's precision, you need to test on a tripod(or just a stable system) where you will be sure that slight camera movements aren't affecting your results.

Even tho setting up a testing system on a tripod may seem to be trivial, for example if your preference is to shoot handheld all the time, testing on a tripod will give you a starting point for working out what the issue may be.
So once you can determine that with camera on tripod, focusing as carefully as you possibly can, and then using mirror lockup to effect the exposure(or a suitably high shutter speed!!) .. and your images are still slightly OOF, what you then need is a way to determine if these images are focused forward or backward of the plane of focus.

if you do test this issue in an easy reproducible manner and confirm that the issue is definitely OOF(and not due to a misadjusted dioptre) .. then the two most likely explanations would be a sightly unsettled focusing screen, or a slightly misadjusted primary mirror.

[andi]

Thanks for the tips guys, next time I'll start a new thread.

I was indeed hand holding the camera, I'll re-test with a tripod and hopefully that'll help! :)

[arthurking83]

Actually looking at the opening post, I reckon that your reply is probably more suited to this thread, rather than a new one.

The OP asked for experiences with focusing screens, and yours was an experience(even tho it's a less than positive one).

I can't see why keeping your current issues in this thread isn't acceptable .. an experience is an experience and for and for future reference for others it's handy to have it all in one place.
The only issue with adding your problem to this thread is that it may get 'messy' if the replies come in from all over the place.

either way you do it(if you do ask for any help) .. it doesn't matter too much.