using the rear screen to aid focus (Page 2): unless you are concerned that the camera AF and lens are not perfect and you want to manually fine tune the system.

Mike Holmes Loc: The Villages Fl

unless you are concerned that the camera AF and lens are not perfect and you want to manually fine tune the system.

Mike Holmes Loc: The Villages Fl

You could be wright. I am just repeating what I saw on a video from a British landscape photographer. His technique, according to him, was used to guaranty perfect focus on a specific object in the landscape.

User ID

Mike Holmes wrote:

I am currently using a Canon 90d dslr camera. I watched a video buy a landscape photographer showing how he used the rear screen to insure perfect focus. He would magnify the image on his rear screen and set his focus and then recompose the image keeping his focus setting and taking the image. He was able to insure his focus was perfect. I am not able to magnify my image prior to taking my photo with my canon 90d. What am I doing wrong?

Since you’ve had difficulty finding it in the printed manual, then download the keyword searchable PDF version and odds are great that you will find it.

Architect1776 Loc: In my mind

randave2001 wrote:

Go to pages 147-148 in your manual and it explains how to zoom in while using live view.

If all else fails read the book.

tcthome Loc: NJ

CHG_CANON wrote:

Consider downloading the PDF version of the manual and using text-search to speed the process of finding the useful sections for specific questions.

For the Live View and focusing, if using back-button focus, first set the position of the AF point in Live View. Then, zoom the display. Finally, hold the BBF until the focus is confirmed at that single AF point. I get much better results for landscape shots via this process.

Shouldn't he do it with a mirrorless camera?

Powergroove75 Loc: Coeur d'Alene, ID

Mike Holmes wrote:

I tried it and I do not have a + or _ selection option on my canon 90d. I suspect my camera does not have that option. Thanks for your reply!!!!!

Top right by your thumb. I have a 90D and I focus this way all the time. Maybe spend some time reading your manual?

Mike Holmes Loc: The Villages Fl

Real men DO NOT read manuals!!!!! Just kidding, you of course, are obvious correct. I think it as a way to guarantee perfect focus.

Delderby Loc: Derby UK

Mike Holmes wrote:

I am currently using a Canon 90d dslr camera. I watched a video buy a landscape photographer showing how he used the rear screen to insure perfect focus. He would magnify the image on his rear screen and set his focus and then recompose the image keeping his focus setting and taking the image. He was able to insure his focus was perfect. I am not able to magnify my image prior to taking my photo with my canon 90d. What am I doing wrong?

I presume you are referring to manual focus. Having used only Pan. M4/3 for 12 years, I am unfamiliar with Canon, but I can magnify in my viewfinder for focussing, which is great for perfect focus.

fetzler Loc: North West PA

Architect1776 wrote:

If all else fails read the book.

RR RTFM

LEWHITE7747 Loc: 33773

Triplets wrote:

I don't own a Canon camera but I was looking at an image of the back of the 90D. In the upper right corner there are 2 buttons -- a"-" and a "+". While in live view, have you tried pressing the "+" button? That works for me on a Nikon D750.

Regards,

Dennis

That is what I use.

Buckeye73

In live view there is an icon of a magnifying glass. Tap it once and the subject is magnified 5 times, tap it again and it magnifies 10 times, tap again and it goes back to a magnification of 1. This for manual focus. You can use auto focus to get it close and then refine it in manual focus. I have the 90D.

Mike Holmes Loc: The Villages Fl

Thanks everyone, I have found the ability to magnify the image in the rear view finder.

RWCRNC Loc: Pennsylvania

Should be able to. I can on my 70d

Mark Sturtevant Loc: Grand Blanc, MI

There is also the little joystick button on the back. Once the selection area is defined, you can use that to move the selection area to where you want to zoom in. With a camera mounted on a tripod, you don't need to zoom out to take the picture.

amfoto1 Loc: San Jose, Calif. USA

Mike Holmes wrote:

I am currently using a Canon 90d dslr camera. I watched a video buy a landscape photographer showing how he used the rear screen to insure perfect focus. He would magnify the image on his rear screen and set his focus and then recompose the image keeping his focus setting and taking the image. He was able to insure his focus was perfect. I am not able to magnify my image prior to taking my photo with my canon 90d. What am I doing wrong?

Hi Mike,

It sounds like you got the answer to your question. That's great.

I have a couple things to add because you mention "recomposing" after focusing:

If you're using a zoom and the recomposing involves changing the focal length, you need to be aware that many modern zooms are "varifocal" designs. What that means is that the lens doesn't maintain focus when the zoom is used. The opposite is a "parfocal" zoom, which maintains perfect focus regardless. But those are more complex designs that require very precise internal calibration, which usually translates to higher cost. Some of the most extreme of these are professional "cine" lenses for video cameras, which can cost 10X more than comparable still camera lenses. (Those cine lens prices are steep for other reasons too... it's not just their parfocal design.)

It's pretty easy to test your lenses to see whether they are varifocal or not. Just set up on a target with a lot of detail where focus errors would be obvious (like a brick wall), then focus at one end of the zoom range and take a shot, then zoom to the other end without refocusing and take a 2nd shot... later enlarge and compare the two to see if there is focus error in the second shot. You should do this at different distances, too... such as near the lens' minimum focus distance, at a middle distance and out near infinity. This because some lenses are semi-parfocal (or semi-varifocal), where the maintain focus at some distances, but not at others (Canon's 70-200s tend to be a slightly varifocal at close distances).

Also... maybe the video you watched covered this... when you recompose after focusing you MUST turn off AF or at least separate it from the shutter release button (search "back button focusing"). If your camera is set to One Shot, so long as you maintain half-press on the shutter release that can keep AF "locked" where you set it while your recompose. But if lift off the shutter release button and then reapply half-press after recomposing (or use the AF On button) while using AI Servo you'll see the camera changing focus once you've recomposed.