Railfan Technology > Manual Focus

Considering upgrading to a mirror less camera from a Canon Rebel 6 which has served well for a decade with one exception. Occasionally I need to use manual focus (shooting through a fence or wanting to work around the auto focus with a "busy" scene with a lot of foreground elements. Any opinions out there as to which of the new crop of cameras has good manual focus capability? Specifically, I find it difficult to tell when something is in focus looking through the viewfinder while rotating the focus ring back and forth. Thanks for any insights. 

There's a method called back-button focus that is found on YT and numerous photog advice websites. Basically program a button to use the focus motor and sensors to focus on a subject and then move to the composition as intended, without refocusing when the shutter button is pressed. 

There's also discsuuions about using film style manual lenses on modern cameras, using adapters or whatever. Once again YT and specic advice websites present the idea and more details for make and models. I was really happy using the focus barrel and the f-stop marking for depth of field for landscapes. But designs change.

+ not that the exact steps to program BBF depends on camera make and model, it's not just one selection and done.



Edited 1 time(s). Last edit at 08/01/26 12:24 by TCnR.

If you have FB here's a quick video that explains back-button focus.

https://www.facebook.com/reel/2090812075195762

My Olympus (now OM System) cameras have a manual focus assist feature.  As you turn the focus ring, it will magnify the image in the viewfinder ( or screen ) so you can easily tell whether or not you're in focus.  As soon as you stop turning the focus ring, the image returns to normal.  I assume other brands have a similar feature.
Previous responses refer to back button focusing.  I don't think that is the same as manual focus.
Hope this helps,
Paul
 

I have a Nikon Z6, and these phone pictures of the screen shows the camera pointing at a label maker in manual focus-- the red square can be centered in frame, or moved anywhere within the frame such as the upper right corner if that's where your subject is, and as you turn the focus ring in manual mode, it turns green once the object within square is in focus. Works great for all sorts of uses! 

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revrobin Wrote:
> manual focus (shooting through a fence or wanting
> to work around the auto focus with a "busy" scene
> with a lot of foreground elements. 

Additional photos... The Z6 takes great photos through chainlink, or even stronger fencing. Here's an example at CalTrain's Milbrae station, which has a fence much thicker than chainlink; first image was taken with my phone showing how far back I am from the fence, and that the live view shows no visuals of the fence. The focus square is showing red because I was busy taking this pic with the phone, but same principle applies, just set the square where you want it, and it will turn green once in focus. Also note the shutter speed is 1/6400 of a second, made possible due to the large frame and lots of light coming through.

Second and third photos were taken with the Z6 + 70-200mm lens-- second photo aperture was set at f/16, so you clearly see the fence. The third photo is the same exact location and composition (camera did not move up toward the fence), but with aperture set at f/2.8, and you can barely see a hint of fuzz in the clouds at the top.

Full frame cameras require a longer focal length than a crop-sensor camera, so the longer focal length combined with the larger sensor, produce a noticeably shallower depth of field at the same f-stop, which helps with those fence shots.



Edited 1 time(s). Last edit at 08/03/26 08:24 by F40PHR231.

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Thanks, I will look into the back button and also impressed with the photos from the Nikon.