Manual focus?magic lantern?

Hi all. Recently picked up a rokinon 85-1.4 and having some focus issues on the 60d. I tried focus peaking in ml but it doesn't seem to work in the view finder only on live view. Is there a chip one can install easily on MF lens to get focus confermation. Also seperate question how does a split screen ficus screen help on MF lens. I am making a amazon order later this week wondering if I shiyjd get a split screen. Will that help me focus the rokinon and if imnot using the rokinon will it affect my view with other lenses. Thanx in advance

Chips are available, and inexpensive, and could probably be glued to the Rokinon mount, but none of the focus confirm chips I have tried have been accurate enough to give satisfactory results on a fast lens like an 85/1.4 wide open.

Magnified Liveview, followed by ML focus peaking are the best bets, I don't know if the crop bodies have focus screens that are easily interchangeable. On the full frame bodies the precision screen helps a lot.

ML, at least on the 5Dii version, has a feature where there is a small box in Liveview that shows the magnified view inside the fullsized image, like picture-in-picture, and that box can be joysticked to the area desired to be in focus so that you can focus zoomed in and still maintain framing. It is a little cumbersome until you get used to it, but it does work. It will even show contrast detect focus confirmation based on parameters that you can choose when you set it up in the menu.

thanx for the reply,yes the 60d and other crops have replaceable focus screens,how do they assist in focus on manual lenses,also ml has the feature your talking about,i fooled around with it last night,i was hoping for something to help me with focus thru the view finder,i only use live view on a tripod,i use the view finder for hand held shots,thanx again for any info

On the 60D the viewfinder is strictly optical. Therefore, the software of ML will have absolutely no effect on manual focusing using only the VF, as you have found out.

A split prism focusing screen was the standard focusing screen back in the pre-AF days of SLRs.

I assume that you are asking an honest question about it's use. The split in the focusing screen is found inside a circle at the center of the viewfinder. One should place the split on something in your scene that includes a vertical line. The split will shift the bottom half of the split from the top half of the split, making your vertical line not "line up." That is, the vertical line will not look continuous throughout the circle if it is out of focus.

|...............|
_ (in focus) vs............... _ (out of focus)
|...............|

Other features of the that type of focusing screen included a "ground glass" type of circle around the split circle that was more precise than the rest of the viewfinder.

What made this really work well, though, was that back in that day lenses were made with a much longer focusing "throw". That is, you had to rotate the focusing ring on the lens much further than today's lenses to move from one focal distance to another.

Today's lenses are made with a very short throw so that AF motors don't have to move the focusing ring very much to move the focusing elements. This makes the AF focusing faster and provides less wear to the focusing motor. But, it makes MF with such a short throw VERY painful. I miss my old MF lenses!

While changing your focus screen to a split screen will make your your manual focusing easier, it MAY negatively affect the accuracy of your exposure metering. Be sure to research that effect before purchasing. Some cameras allow a setting in the menu to somewhat offset this inaccuracy that the different focus screen introduces.

I hope that this (and my crude drawing) are helpful to you.

Dwain

Honestly it just takes practice in the beginning. Even with a split prism/AF confirm chip, use it for a couple of weeks and you'll get the hang of it.

DwainRowe wrote in post #17059391
On the 60D the viewfinder is strictly optical. Therefore, the software of ML will have absolutely no effect on manual focusing using only the VF, as you have found out.

A split prism focusing screen was the standard focusing screen back in the pre-AF days of SLRs.

I assume that you are asking an honest question about it's use. The split in the focusing screen is found inside a circle at the center of the viewfinder. One should place the split on something in your scene that includes a vertical line. The split will shift the bottom half of the split from the top half of the split, making your vertical line not "line up." That is, the vertical line will not look continuous throughout the circle if it is out of focus.

|...............|
_ (in focus) vs............... _ (out of focus)
|...............|

Other features of the that type of focusing screen included a "ground glass" type of circle around the split circle that was more precise than the rest of the viewfinder.

What made this really work well, though, was that back in that day lenses were made with a much longer focusing "throw". That is, you had to rotate the focusing ring on the lens much further than today's lenses to move from one focal distance to another.

Today's lenses are made with a very short throw so that AF motors don't have to move the focusing ring very much to move the focusing elements. This makes the AF focusing faster and provides less wear to the focusing motor. But, it makes MF with such a short throw VERY painful. I miss my old MF lenses!

While changing your focus screen to a split screen will make your your manual focusing easier, it MAY negatively affect the accuracy of your exposure metering. Be sure to research that effect before purchasing. Some cameras allow a setting in the menu to somewhat offset this inaccuracy that the different focus screen introduces.

I hope that this (and my crude drawing) are helpful to you.

Dwain

thank you so much for taking the time to fully explain the split,i totally get it now,i think for 25 i will try one out,that drawing u made makes good sense,i have 2 mf lenses and i enjoy using them so if the split screen will help a bit ill give her a go,i think my 60d has a menu for changing the screen,how would the view finder affect metering,forgive me if i sound stupid does metering bounce off the mirror,does metering come after the focus screen,so the light comes thru the lens bounce off the mirror thru the focus screen into the camera,sorry if that doesn't make sense but I'm not sure how metering works,again thanx for the great explanation

genesimmons wrote in post #17059928
thank you so much for taking the time to fully explain the split,i totally get it now

You're welcome.

genesimmons wrote in post #17059928
forgive me if i sound stupid does metering bounce off the mirror,does metering come after the focus screen,so the light comes thru the lens bounce off the mirror thru the focus screen into the camera,sorry if that doesn't make sense but I'm not sure how metering works,again thanx for the great explanation

Katzeye is the brand with which I most familiar. From their website:

Metering Information

The KatzEye™ focusing screen for the Canon 40D/50D/60D has little to no effect on light metering in Evaluative or Center Weighted metering modes. Partial and Spot metering modes are somewhat more affected, depending on conditions. We recommend use of the Ef-A selection in the camera’s focusing screen type custom function for most accurate results. Please see your owner’s manual for instructions on adjusting the custom function settings. Detailed test results for each of the four metering modes are as follows*:

Evaluative Metering Mode: Our testing showed evaluative mode to be within factory tolerance for all lenses having a maximum aperture of f4.5 or larger (lower f number). AF lenses with a maximum aperture of f5.6 or slower (higher f number) will overexpose slightly. With an f5.6 AF lens, we recommend an exposure compensation of -2/3EV. Manual (non-CPU) lenses with a maximum aperture of f5.6 or slower (higher f number) will underexpose slightly. With an f5.6 non-CPU lens, we recommend an exposure compensation of +2/3EV.
Center Weighted Average (CWA) Metering Mode: Our testing showed CWA metering mode to be within factory tolerance for all lenses having a maximum aperture of f4.5 or larger (lower f number). Lenses with a maximum aperture of f5.6 or slower (higher f number) will underexpose very slightly. With an f5.6 lens, we recommend an exposure compensation of +1/3EV.
Partial Metering Mode: Our testing showed partial metering mode to be within factory tolerance for all lenses having a maximum aperture of f2.0 or larger (lower f number). Lenses having a maximum aperture smaller than f2.0 (lager f number) will show a shift toward increased exposure. The shift will be greater for lenses with smaller maximum apertures. When using partial metering mode, it is advisable to first take a test shot, check the histogram, and adjust exposure compensation as required. Starting points for exposure compensation are as follows: f2.8 lens: -1/3EV, f4.0 lens: -2/3EV, f5.6 lens: -1EV.
Spot Metering Mode: Our testing showed spot metering mode to be within factory tolerance for all lenses having a maximum aperture of f2.0 or larger (lower f number). Lenses having a maximum aperture smaller than f2.0 (lager f number) will show a significant shift toward increased exposure, with the shift increasing for lenses with smaller maximum apertures. Spot metering mode is not recommended when using a split prism focusing screen except with very fast prime lenses. However, if spot mode must be used, it is strongly advised to first take a test shot, check the histogram, and adjust exposure compensation as required.

* Note: Metering test results presented are based on testing of the 40D model. While results are expected to be similar for the 50D and 60D, users of these models are strongly encouraged to take a test shot and check the histogram before beginning any critical shooting.


Katzeye LINK

This focus screen is more than $25 so the one you choose for that dollar amount may not perform as well.

If I remember correctly, the exposure sensors are above the focus screen somewhere (??) in the pentaprism housing. So the light has to pass through the focus screen first. I'm sure some optical physicist will chime in here to correct me soon.

Dwain

again thanx for the great informative reply,the screen i was looking at was a fotodiox brand,it has decent reviews on amazon,if the focus screen is such an important part of manual focus why doesn't canon have a better one from the factory,is it because most users of dslrs use af?i noticed some dust particles on my focus screen last night,i though it was view finder but i cleaned that and they were still there,i took the lens off and looked up at the focus screen and literally barely touched the door clip and the door opened and the screen almost fell out in front of me,i carefully cleaned it and used my blower to blow inside the door opening while camera was held upside down,i carefully put the screen back in and checked,dust was gone,seemed like a cheap pice of plastic and hard to see thru,does the split one look the same kinda opaque looking plastic,could u shoot without the screen at all,i could see thru the view finder very clear when the screen was off,didn't put lens on and take a photo though,again thanx for the info