Converting focal length to full-frame is pointless

Saturday 14 June 2025, 22:11 by Nando Harmsen | 4,067 views | 3 comments

This article was translated from Dutch with the help of AI. Read the original.

Do you use a camera with a crop factor? Do you still convert the focal length to what it would be on a full-frame camera? Stop doing that. It is no use at all. It certainly does not help your photography.

I know there are still photographers who convert the focal length to what it would be on a full-frame camera. First of all, focal length does not change. It is the angle of view, but that is beside the point.

Too much in the frame: Zoom in. It is about how large it is in the frame, not what it would be on another camera.
The angle of view of a focal length is indeed different on a full-frame camera than on a crop sensor. If you are comparing them, you do indeed need to convert it. But ask yourself, why do you want to compare them?

What added value does converting it give you? Do you use a full-frame camera and a crop camera side by side? If so, do you need an angle of view that is exactly the same on both cameras? Or do you simply use a camera with a smaller sensor?

Too little in the frame? Zoom out. It is about the angle of view you have, not what it would be on another camera.
Forget about converting it. There is no need. It gives you absolutely no useful information. It only causes headaches and confusion. You do not use a full-frame camera, only a crop camera. That is why converting it is pointless.

Zoomed out. It does not matter which number goes with it, or which sensor size. It is about having the angle of view you want.
Just look through your camera or at your screen. Look at what you have in the frame. Is there too little? Zoom out. Is there still too little, choose a lens with a wider angle. The number that goes with that focal length is unimportant. What you have in the frame is what matters.

Zoomed in. It does not matter which number goes with it, or which sensor size. It is about having the angle of view and magnification you want.
Do you have too much in the frame and want to see something larger in the frame? Zoom in. If it is still shown too small, choose a lens with more telephoto reach. The number that goes with that focal length is unimportant. Only what you have in the frame counts.

Forget about converting to full-frame. There is no need. The number belonging to the focal length you are using is not even important. Only the angle of view you have matters, and you can see that when you look through the viewfinder or at the screen.

Share: WhatsApp Facebook

About the author

Nando Harmsen has been photographing for more than 40 years. He specialises in wedding photography and landscape photography. Nando also gives talks, workshops, masterclasses and photo trips, and regularly reviews new and interesting equipment.

Why the crop factor also affects depth of field
by Nando Harmsen
Difference in depth of field when cropping or using a teleconverter
by Nando Harmsen
The opposite of cropping
by Nando Harmsen
Cropping is good, but don't overdo it with animal photos
by Nando Harmsen
Crop or use a teleconverter?
by Nando Harmsen
Photographing or cropping a panorama
by Nando Harmsen

Show every article in Personal

home

3 comments

Mac wrote on Monday 16 June 2025 at 07:58 | reply
I converted it at first, because that way I knew what angle of view I had on FF. Which was useful after years of analog photography, where I knew which lens I had to use for which photo.
But after years of photographing with an APS-C camera, I know which lens to use when I want a certain angle of view, so I don't convert anymore
Translated from Dutch.

Hans van Oers wrote on Tuesday 17 June 2025 at 10:53 | reply
Canon has indeed now made an RF 24-105mm 2.8, okay. The reason I have been using a 24-70mm 2.8 for home portraits for years on a 1.6x crop camera is the pleasure and convenience of photographing with 2.8 aperture between an angle of view of 70 and 112mm on my Canon R7 now, without having to change lenses all the time. The EF-S 17-55mm and the Tamron 35-150mm were not really my favourites.
Translated from Dutch.

Paul van Aken wrote on Tuesday 17 June 2025 at 15:33 | reply
Converting is indeed pointless, but if you've worked with SLR for more than 40 years before switching to DSLR in DX format, it's something to hold on to.
Translated from Dutch.

Have your say

Please note: Articles older than a week can only be commented on by signed-in visitors.
Would you still like to comment? sign in or create a free account.

Become a better photographer every week

A practical photography tip in your inbox every week.
39,178 photography enthusiasts already receive the tips! More about the weekly mail. Or keep up to date via Facebook. Sign-up secured with Google reCaptcha.

Elja Trum

Photofacts; everything to do with photography!

Would you like to take better photos and keep up with what is happening in photography? Photofacts publishes articles that teach you something about photography — from a product announcement to a practical shooting tip or a look at a website. Photofacts covers photography every day and is a hobby project of Elja Trum's that got out of hand. The articles are written by a team of volunteer authors. If you would enjoy writing one or more articles for Photofacts, do get in touch.More about Photofacts

Photofacts is made possible in part by