Crop Factor

**Bob 256** · 12-30-2021, 07:26 PM - **1 Like**

Yes, that thread title might be designed as click bait and yes, I may have been known as a rabble-rouser in my early years, but in this case I just thought a well explained video about a subject which often finds discussion in this forum, might be of interest to those who have questions about it. I know of at least one fist fight started over the issue of "crop factor" so please no chair slinging. I happen to come across this video while looking for something totally different, but it caught my eye and I ended up watching it in its entirety. Although it doesn't feature any Pentax products, it contains some good examples and the presenter is knowledgeable in the field (not related nor do I know him other than through this video).

That said, enjoy (watch it clear to the end statement and take a deep breath):

You Tube

Last edited by Bob 256; 12-30-2021 at 07:33 PM.

pschlute · 12-31-2021, 02:53 AM - **2 Likes**

The video is an old one, and the "well explained" bit is not getting across if you read some of the comments on YT.....

like this one ... "One point unaddressed re crop sensors though is the fact they provide an instant boost in magnification for macro photography which is one advantage of not going full frame"

It seems the crop factor is as misunderstood as ever

Oldbayrunner · 12-31-2021, 06:36 AM

Crop factor would not be my main reason to use my Apsc K3 ll for some macro work vs using my Full Frame K1. Personally I think the use of the term crop factor has way out served it's useful purpose. As much as I disagree with much of TN's posted information personally I did find this one to have a lot of good information I hadn't given much thought to.

bertwert · 12-31-2021, 09:25 AM - **1 Like**

Originally posted by pschlute

The video is an old one, and the "well explained" bit is not getting across if you read some of the comments on YT.....

like this one ... "One point unaddressed re crop sensors though is the fact they provide an instant boost in magnification for macro photography which is one advantage of not going full frame"

It seems the crop factor is as misunderstood as ever

The fact that it's a 20 minute video to explain a 2 minute concept probably doesn't help - I haven't watch it but I wouldn't be surprised if the presenter was overcomplicating it.

pschlute · 12-31-2021, 09:28 AM

Originally posted by bertwert

The fact that it's a 20 minute video to explain a 2 minute concept probably doesn't help

**Bob 256** · 12-31-2021, 10:04 AM - **1 Like**

Originally posted by bertwert

The fact that it's a 20 minute video to explain a 2 minute concept probably doesn't help - I haven't watch it but I wouldn't be surprised if the presenter was overcomplicating it.

Then watch it. He goes well beyond the 2 minute concept and shows some real world examples of how CF affects three different formats. Simple enough explanations for me and the fact that "it's an old video" doesn't make it irrelevant. I have a pretty good concept of CF but still learned a few new things with this video (and there are some pretty awesome lenses shown in the examples).

**c.a.m** · 12-31-2021, 10:47 AM - **1 Like**

Originally posted by Bob 256

He goes well beyond the 2 minute concept and shows some real world examples of how CF affects three different formats.

I watched it and thought it was a comprehensive, clear, and drama-free treatment of the subject. While I don't need to compare different formats (I shoot APS-C only), I found that the tutorial presented an interesting overview of the subject. It was humorous in spots, e.g., the comparison of the Nikon 600mm f/4 beast to the M43 300/4 mini-beast. Also interesting that Tony mentioned the potential of smaller formats for certain use cases.

As for his presentation style, I think he was well-prepared and had all of his props close at hand. His examples were relevant, and he walked through the math in a way that would suit any viewer. Pretty good job, I'd say.

- Craig

**marcusBMG** · 12-31-2021, 02:37 PM - **1 Like**

Well well well, maybe Tony Northrupp has finally got it re crop factor, only taken him about 10 yrs! He has previously contributed greatly to the confusion and angst.

**Bob 256** · 12-31-2021, 02:43 PM

Originally posted by marcusBMG

Well well well, maybe Tony Northrupp has finally got it re crop factor, only taken him abut 10 yrs! He has previously contributed greatly to the confusion and angst.

I did see him do a little earlier presentation and he didn't quite seem to understand CF himself, but I think in this video he pretty much nailed it. As confusing as CF can be, 10 years is about right

**clackers** · 12-31-2021, 04:07 PM - **1 Like**

Originally posted by Bob 256

I did see him do a little earlier presentation and he didn't quite seem to understand CF himself

Yep, I advise for anyone to seek better sources of knowledge about photography than Tony and Chelsea Northrup.

Lord Lucan · 01-01-2022, 06:49 AM

Originally posted by Bob 256

I did see him do a little earlier presentation and he didn't quite seem to understand CF himself

Maybe that was the one I saw, or maybe he gets it wrong in other videos too. I was watching him, and thought I had misheard or misunderstood what he was saying. So I re-played it and then realised that the man did not know what he was talking about. I've not watched him since.

The trouble is that Northrup sounds so authorative, coming over as if he knows everything. He doesn't, but many people assume that he does.

**Pål Jensen** · 01-01-2022, 08:11 AM

Originally posted by pschlute

The video is an old one, and the "well explained" bit is not getting across if you read some of the comments on YT.....

like this one ... "One point unaddressed re crop sensors though is the fact they provide an instant boost in magnification for macro photography which is one advantage of not going full frame"

It seems the crop factor is as misunderstood as ever

Technically you are correct but we photographers are not concerned with magnification but frame filling properties. 1:1 magnification on APS fill 50% more of the frame than on FF.

normhead · 01-01-2022, 08:18 AM - **1 Like**

10 years ago, when all this started my response was "forget 'crop factor' look through the viewfinder of your camera, figure out what you need to get the image you want." Nothing has changed. Zoom lenses have removed any use of crop factor type calculations. Frame through the viewfinder, not with the aid of a crop factor table. For comparison purposes I used my wife's k-5 and DFA 28-105, at ~35mm, used my K-1 with the same lens at ~50mm. I kept the edges of the frame constant and used the zoom to get the desired view, on both images. This produced no discernible difference in the image viewed at the size of the APS-c image.

I guess if you use two formats that use the same lenses and mostly use primes, being able to figure out crop factor might be a thing. Personally, I've never found it any use at all. I know what lens I want to use on which system when I look at the scene. Experiential knowledge trumps math in that it's instant.

The viewfinder is real.( At least with an OVF) The crop factor is derivative, it's only as good as your math skills.

12-31-2021, 02:53 AM - 2 Likes	#2
pschlute Moderator Loyal Site Supporter Join Date: Mar 2007 Location: Surrey, UK Photos: Gallery Posts: 8,214	The video is an old one, and the "well explained" bit is not getting across if you read some of the comments on YT..... like this one ... "One point unaddressed re crop sensors though is the fact they provide an instant boost in magnification for macro photography which is one advantage of not going full frame" It seems the crop factor is as misunderstood as ever Last edited by pschlute; 12-31-2021 at 05:01 AM.

12-31-2021, 02:37 PM - 1 Like	#8
marcusBMG Site Supporter Join Date: Nov 2012 Location: North Wales Photos: Gallery \| Albums Posts: 2,870	Well well well, maybe Tony Northrupp has finally got it re crop factor, only taken him about 10 yrs! He has previously contributed greatly to the confusion and angst. Last edited by marcusBMG; 01-01-2022 at 03:59 AM.

01-01-2022, 08:18 AM - 1 Like	#13
normhead Pentaxian Join Date: Jun 2007 Location: Near Algonquin Park Photos: Gallery \| Albums Posts: 40,451	10 years ago, when all this started my response was "forget 'crop factor' look through the viewfinder of your camera, figure out what you need to get the image you want." Nothing has changed. Zoom lenses have removed any use of crop factor type calculations. Frame through the viewfinder, not with the aid of a crop factor table. For comparison purposes I used my wife's k-5 and DFA 28-105, at ~35mm, used my K-1 with the same lens at ~50mm. I kept the edges of the frame constant and used the zoom to get the desired view, on both images. This produced no discernible difference in the image viewed at the size of the APS-c image. I guess if you use two formats that use the same lenses and mostly use primes, being able to figure out crop factor might be a thing. Personally, I've never found it any use at all. I know what lens I want to use on which system when I look at the scene. Experiential knowledge trumps math in that it's instant. The viewfinder is real.( At least with an OVF) The crop factor is derivative, it's only as good as your math skills. Last edited by normhead; 01-01-2022 at 08:35 AM.

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12-31-2021, 06:36 AM	#3
Oldbayrunner Pentaxian Join Date: Mar 2013 Posts: 1,665	Crop factor would not be my main reason to use my Apsc K3 ll for some macro work vs using my Full Frame K1. Personally I think the use of the term crop factor has way out served it's useful purpose. As much as I disagree with much of TN's posted information personally I did find this one to have a lot of good information I hadn't given much thought to.

12-31-2021, 09:25 AM - 1 Like	#4
bertwert Veteran Member Join Date: Jun 2015 Location: Golden, BC Posts: 15,172	Originally posted by pschlute The video is an old one, and the "well explained" bit is not getting across if you read some of the comments on YT..... like this one ... "One point unaddressed re crop sensors though is the fact they provide an instant boost in magnification for macro photography which is one advantage of not going full frame" It seems the crop factor is as misunderstood as ever The fact that it's a 20 minute video to explain a 2 minute concept probably doesn't help - I haven't watch it but I wouldn't be surprised if the presenter was overcomplicating it.

12-31-2021, 09:28 AM	#5
pschlute Moderator Loyal Site Supporter Join Date: Mar 2007 Location: Surrey, UK Photos: Gallery Posts: 8,214	Originally posted by bertwert The fact that it's a 20 minute video to explain a 2 minute concept probably doesn't help

12-31-2021, 10:04 AM - 1 Like	#6
Bob 256 Site Supporter Join Date: Jun 2008 Location: Idaho Photos: Gallery Posts: 2,378 Original Poster	Originally posted by bertwert The fact that it's a 20 minute video to explain a 2 minute concept probably doesn't help - I haven't watch it but I wouldn't be surprised if the presenter was overcomplicating it. Then watch it. He goes well beyond the 2 minute concept and shows some real world examples of how CF affects three different formats. Simple enough explanations for me and the fact that "it's an old video" doesn't make it irrelevant. I have a pretty good concept of CF but still learned a few new things with this video (and there are some pretty awesome lenses shown in the examples).

12-31-2021, 10:47 AM - 1 Like	#7
c.a.m Site Supporter Join Date: Jan 2013 Location: Ottawa, Canada Photos: Gallery \| Albums Posts: 4,192	Originally posted by Bob 256 He goes well beyond the 2 minute concept and shows some real world examples of how CF affects three different formats. I watched it and thought it was a comprehensive, clear, and drama-free treatment of the subject. While I don't need to compare different formats (I shoot APS-C only), I found that the tutorial presented an interesting overview of the subject. It was humorous in spots, e.g., the comparison of the Nikon 600mm f/4 beast to the M43 300/4 mini-beast. Also interesting that Tony mentioned the potential of smaller formats for certain use cases. As for his presentation style, I think he was well-prepared and had all of his props close at hand. His examples were relevant, and he walked through the math in a way that would suit any viewer. Pretty good job, I'd say. - Craig

12-31-2021, 02:43 PM	#9
Bob 256 Site Supporter Join Date: Jun 2008 Location: Idaho Photos: Gallery Posts: 2,378 Original Poster	Originally posted by marcusBMG Well well well, maybe Tony Northrupp has finally got it re crop factor, only taken him abut 10 yrs! He has previously contributed greatly to the confusion and angst. I did see him do a little earlier presentation and he didn't quite seem to understand CF himself, but I think in this video he pretty much nailed it. As confusing as CF can be, 10 years is about right

12-31-2021, 04:07 PM - 1 Like	#10
clackers Otis Memorial Pentaxian Join Date: Jul 2013 Location: Melbourne Photos: Albums Posts: 16,397	Originally posted by Bob 256 I did see him do a little earlier presentation and he didn't quite seem to understand CF himself Yep, I advise for anyone to seek better sources of knowledge about photography than Tony and Chelsea Northrup.

01-01-2022, 06:49 AM	#11
Lord Lucan Pentaxian Join Date: Sep 2017 Location: South Wales Photos: Gallery Posts: 2,977	Originally posted by Bob 256 I did see him do a little earlier presentation and he didn't quite seem to understand CF himself Maybe that was the one I saw, or maybe he gets it wrong in other videos too. I was watching him, and thought I had misheard or misunderstood what he was saying. So I re-played it and then realised that the man did not know what he was talking about. I've not watched him since. The trouble is that Northrup sounds so authorative, coming over as if he knows everything. He doesn't, but many people assume that he does.

01-01-2022, 08:11 AM	#12
Pål Jensen Site Supporter Join Date: Dec 2007 Location: Norway Photos: Albums Posts: 4,371	Originally posted by pschlute The video is an old one, and the "well explained" bit is not getting across if you read some of the comments on YT..... like this one ... "One point unaddressed re crop sensors though is the fact they provide an instant boost in magnification for macro photography which is one advantage of not going full frame" It seems the crop factor is as misunderstood as ever Technically you are correct but we photographers are not concerned with magnification but frame filling properties. 1:1 magnification on APS fill 50% more of the frame than on FF.