Manual focus impossible for some?

Is it possible some people simply can't achieve a good manual focus? I wear contacts and have good vision in general, but there is no way I can manually focus any of my lenses as well as the auto focus does. Sometimes I'll play around with it and stop when I think I'm there, then auto focus, only to find I was way off. Or at least enough to scrap the photo.

The camera and lens will have something to do with it. DSLRs aren't built with manual focus in mind, and as such they don't have the precision matte or split screens older film cameras came with. You can buy precision focusing screens for some models though. I had an EG-S precision matte screen in my old 5DII and it made a huge difference.

Manual focusing through the VF is difficult but try using live view and zoom in 10x.

As Scatterbrained said, dSLRs aren't built with manual focus, but they prioritized giving the user a brighter viewfinder because half of the light was passing thru the reflex mirror to be diverted downward to the AF sensor rather than it going out to the eyepiece (like in a manual focus SLR). In view of the brightness goal, a 'finer' texture to the focus screen lets more light thru the focus screen but decreases the precision of the focus seen by the eye. Compound that with the lack of a center focus aid that does not hurt the accuracy of the light metering, and you have all the makings of a suboptimal manual focus experience.

gjl711 wrote in post #18413427
Manual focusing through the VF is difficult but try using live view and zoom in 10x.

X2. Even better is live view through a Camranger or such to an iPad. I use a 12" iPad Pro. Shoot a lot of tripod mounted low angle pics, which my back and knees don't support anymore. Manual Focus is a breeze.

Then I used MF lenses on DLSR it was hard and slow. SLRs with fancy circles in the middle of the focusing screen not giving me confidence either. TLR ground glass focusing was even more difficult and LF camera ground glass focusing was nothing but annoying to me. The only MF focusing I'm comfortable with is RF.
New arrivals from Sony and Fuji have good options for MF as well.

I used to shoot video (which forces LiveView) with old Nikon lenses with EF adapters on my 60D and 70D. I used a 3x magnifying hood on the LCD and also Magic Lantern replacement firmware with Focus Peaking enabled. I could manually focus pretty well. But there are some caveats here.

1. You need Magic Lantern to do focus peaking on Canon. Not all models are supported. The 5D2, 5D3, T2i, 60D and 70D are supported (though not fully with the 70D). Note, however, that Sony and Panasonic (maybe other) mirrorless cameras do support focus peaking.

2. To get the magnifying hood to stick on the camera requires either a special mount that screws into the tripod socket (and usually provides some kind of quick release clamp compatibility, either Arca Swiss or Manfrotto) or you have to glue a frame to LCD.

3. Manual focus lenses are easier to focus manually because they have a long throw on the focus ring (e.g., the ring turns more in either direction to change focus). Auto focus lenses have a short throw for faster auto focusing, but are more difficult to manually focus precisely.

4. The wider the lens the harder it is to hit precision focus because details are smaller.

5. Manual focus on moving subjects is more about knowing the "feel" of the lens' focus ring and checking/adjusting on the LCD. It takes a lot of practice and is complicated by some lenses focus ring turning the opposite direction (Nikon vs Canon).

Since moving to the 80D I've given-up on manual focus, both because I can't get focus peaking (no Magic Lantern support) and because the camera's subject tracking and touch-to-focus capabilities are so good I really don't need it. I still have the manual lenses and the 60D as a backup, but haven't used them in more than a year.

I also wear contact lenses and also need reading glasses (+1) when wearing the contacts. I find it impossible to focus through the eye level viewfinder with this combo. When not wearing contacts I don't need the reading glasses, but still it's very hard to manually focus through the viewfinder. It does get better with practice, but autofocus has become so quick and accurate I don't bother unless I'm doing a very shallow DOF portrait, and then I'll use LiveView with 10x magnification on the subject's eyes.

Manual focus confirmation works OK with EF lenses. When I had a 5Dc, I got a third party split prism screen to be able to manually focus. I don't do as much MF now, but if I did with the 5D3 or 7D2, I'd have a zone active and then manually focus. They do a pretty good job of showing what AF point is in focus.

Scatterbrained wrote in post #18413423
The camera and lens will have something to do with it. DSLRs aren't built with manual focus in mind, and as such they don't have the precision matte or split screens older film cameras came with. You can buy precision focusing screens for some models though. I had an EG-S precision matte screen in my old 5DII and it made a huge difference.

I thought those screens worked only on the 1Dxx bodies. Does it affect AF in any way? Do you really have the best of both worlds?

Alveric wrote in post #18413720
I thought those screens worked only on the 1Dxx bodies. Does it affect AF in any way? Do you really have the best of both worlds?

There's 3rd party brands that offer split prism, or various "precision", screens for most Canon models. For some Canon models, it's easier to replace a screen (they'll have a tab in front of the screen that will release the holding bracket). 5D3/5D4 doesn't have that (they're assuming you're using focus point confirmation). For models like the 5D3/5D4, you have to remove front screws to release the holding bracket for the focus screen. I've never felt the need to get one for the 5D3. The main thing that it might effect is metering: it has slightly less EV then the standard Canon focus screen.

I used it on the 5DII for years. Worked fine. There is a menu setting in the camera to tell it which focusing screen you are using, then it will compensate. I haven't bothered trying with my 1Dx because I have the Sony for those time when I'm using a MF lens.

On my IR converted T2i I used a combination of Magic Lantern (for the focus peaking) coupled with a Hoodman Loupe Cinema Crane kit. This allowed me to use the rear LCD with a hood loupe that attached via the hotshoe so I could hold the camera and shoot as I normally would, and there was no need to glue anything to the LCD or give up my tripod socket.

Ach, I was confusing it with a split prism focusing screen. Never mind, then. Though, I'm now curious about it. Guess $50 isn't too expensive if it turns out to be really useful with my Zeiss 35mm that is always missing focus.

For trying to get focus in the center, I found the 3rd party split screen worked fine on my 5Dc. Metering wasn't as much effected as well, since you could select the precision screen in the menu. For other Canon models that don't natively offer different focus screens, you might find yourself nudging EC just a tad.

davesrose wrote in post #18413784
For trying to get focus in the center, I found the 3rd party split screen worked fine on my 5Dc. Metering wasn't as much effected as well, since you could select the precision screen in the menu. For other Canon models that don't natively offer different focus screens, you might find yourself nudging EC just a tad.

POTN members have verified up to 2EV error. KatEye used to be very open about changes to metering

https://photography-on-the.net …showthread.php?​p=16465415

https://photography-on-the.net …showthread.php?​p=16465505

KatzEye is no more, though.