Macro lens on APSC and FF

micl161 · 06-06-2018, 09:17 PM - **1 Like**

Just wondering,

If I have a 100mm 1:1 Macro lens with MFD ~ 6". Put this lens on the APSC and FF camera, I believe the MFD of the lens will not change on both camera, then how about the following :

- If the FF photo is 1:1, will the photo from the APSC become 'super macro' like 1.5:1 ?
- Can I move away a little longer from the subject (like 1.5 X 6" to 9") on the APSC camera and still get the 1:1 photo ?

Thanks

stevebrot · 06-06-2018, 09:29 PM - **4 Likes**

Originally posted by micl161

- If the FF photo is 1:1, will the photo from the APSC become 'super macro' like 1.5:1 ?

No, 1:1 is 1:1 (1x magnification) no matter how much you crop.

Originally posted by micl161

- Can I move away a little longer from the subject (like 1.5 X 6" to 9") on the APSC camera and still get the 1:1 photo ?

1:1 is typically available at the minimum focus distance which remains the same regardless of the size of the sensor one is using. If one moves away, one may attain the same framing with APS-C as with 24x36mm FF at 1:1, but at lower magnification (0.67x). The rules are the same as with non-macro lenses. Framing (crop) is not the same as magnification, though it may influence how much magnification is required to attain final display size.

Example: If one takes a photo of a metric ruler stretched across the frame at 1:1 using a 24x36 FF camera, the number of millimeter marks visible will be 35 full marks with 1/2 mark at either side. The same ruler at 1:1 on APS-C will show 24 full marks with 0.55 mark at either side (25.1mm). Backing off so that 35 marks show with a 1/2 mark on each side requires only 1:1.5 (0.67x magnification) at capture, but 1.5x more enlargement at print time than the FF image to make a 24x36cm print.

Steve

Sandy Hancock · 06-06-2018, 09:33 PM - **1 Like**

Strictly speaking, no.

1:1 reproduction means that the image on the sensor is life size.

On a crop sensor you therefore get less of it, so when you enlarge it to the same size it looks more magnified.

[edit]In other words, what Steve said

[/edit]

swanlefitte · 06-06-2018, 10:04 PM - **8 Likes**

Its easier for me to think of 1:1 by visualizing putting the thing i am photographing on the sensor. If i took a coin and pressed it on the sensor that is what the sensor would process. Its actual size. Since the ff sensor is bigger the coin won't take up as much of the sensor as on apsc.

stevebrot · 06-06-2018, 10:17 PM

Originally posted by swanlefitte

Its easier for me to think of 1:1 by visualizing putting the thing i am photographing on the sensor. If i took a coin and pressed it on the sensor that is what the sensor would process. Its actual size. Since the ff sensor is bigger the coin won't take up as much of the sensor as on apsc.

Excellent explanation!

Steve

swanlefitte · 06-06-2018, 10:21 PM

Thanks i was puzzled at one time and this thinking is what got me through it.

Paul the Sunman · 06-06-2018, 10:21 PM - **4 Likes**

Originally posted by swanlefitte

Its easier for me to think of 1:1 by visualizing putting the thing i am photographing on the sensor. If i took a coin and pressed it on the sensor that is what the sensor would process. Its actual size. Since the ff sensor is bigger the coin won't take up as much of the sensor as on apsc.

However, the novice photographer is advised not to press a coin on their sensor.

**UncleVanya** · 06-07-2018, 05:56 AM

The practical impact of all of this is that most of the time the apsc sensor has denser pixels per mm so 1:1 on apsc will have a higher number of pixels on the subject which allows potentially larger enlargements without loss of detail.

LensBeginner · 06-07-2018, 06:19 AM

After "equivalent focal length" (?) and then "equivalent aperture" (??), some clever fellow actually came up with "equivalent magnification"

I don't remember the details, but the same question was posed on the Italian forum, citing IIRC Olympus website, and the technical specification of some macro lenses, which had confusingly different and strange magnification values, like "2:1 on m43" for a 1:1 lens...

So no worries, people who do that for a living get it wrong all the time!

normhead · 06-07-2018, 06:59 AM

Originally posted by UncleVanya

The practical impact of all of this is that most of the time the apsc sensor has denser pixels per mm so 1:1 on apsc will have a higher number of pixels on the subject which allows potentially larger enlargements without loss of detail.

And also sometimes a smaller sensor site camera will capture detail not captured with a camera with larger pixel sites. This almost always favours smaller sensor cameras.

IN a practical sense, since most to the time you are enlarging things with macro, you get more effective enlargement with a smaller sensor. There's nothing quite as disappointing as setting up a macro on a K-3 then changing to a K-1 because of light conditions. And I so often shoot close to the minimum focusing distance moving closer is not an option. On a K-1 minimum focusing distance is more likely to become an issue, because it's harder to fill the frame with a small object.

I only use the K-1 for macro when I don't have enough light to effectively use the K-3 and I want to push to the K-1 high ISO values. If you have a K-70 or K-P even the isn't much of an issue.

micl161 · 06-07-2018, 08:03 AM

Thanks for the ruler and coin example, it seems I understand the rule now, but I'm sure I'll get confuse again sooner or later !

Also thanks for pointing out the advantage of APSC when shooting macro, so many to learn..!

BrianR · 06-07-2018, 08:17 AM

Originally posted by swanlefitte

Its easier for me to think of 1:1 by visualizing putting the thing i am photographing on the sensor. If i took a coin and pressed it on the sensor that is what the sensor would process. Its actual size. Since the ff sensor is bigger the coin won't take up as much of the sensor as on apsc.

Good explanation.

Before I purchased a macro lens I had taken pieces of cardboard and cut rectangles out of them corresponding to the framing I'd get with aps-c at different magnifications. A 16x24mm rectangular with "1:1" label, a 32x48mm hole with a "1:2" label, etc. This let me compare the framing I could get with the macro vs. the lenses I had at their minimum focusing distance. Easy enough to repeat for different sensor formats.

LensBeginner · 06-07-2018, 08:23 AM

Originally posted by BrianR

Good explanation.

Before I purchased a macro lens I had taken pieces of cardboard and cut rectangles out of them corresponding to the framing I'd get with aps-c at different magnifications. A 16x24mm rectangular with "1:1" label, a 32x48mm hole with a "1:2" label, etc. This let me compare the framing I could get with the macro vs. the lenses I had at their minimum focusing distance. Easy enough to repeat for different sensor formats.

It's a great idea!
A variation could be an A5 sized sheet with the various size printed (I think an A4 is too big for that, you don't need to go all the way to 1:10...), that one could laminate and bring with them.
One could also cut it, and get the transparency and resilience from the plastification.

**UncleVanya** · 06-07-2018, 08:27 AM

The Q with a macro lens would be pretty crazy with most subjects!

LensBeginner · 06-07-2018, 08:43 AM - **1 Like**

There you go, I took the liberty of practicing what I preached!

Due credit is given, of course.
And it's another small bit towards the month's quota... I'm just dying to get that K-1...

Remember it's an A5 sheet, not A4! So 148 x 210 mm

06-06-2018, 09:17 PM - 1 Like	#1
micl161 Senior Member Join Date: Mar 2014 Location: Hong Kong Posts: 127	Macro lens on APSC and FF Just wondering, If I have a 100mm 1:1 Macro lens with MFD ~ 6". Put this lens on the APSC and FF camera, I believe the MFD of the lens will not change on both camera, then how about the following : - If the FF photo is 1:1, will the photo from the APSC become 'super macro' like 1.5:1 ? - Can I move away a little longer from the subject (like 1.5 X 6" to 9") on the APSC camera and still get the 1:1 photo ? Thanks

06-06-2018, 09:29 PM - 4 Likes	#2
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by micl161 - If the FF photo is 1:1, will the photo from the APSC become 'super macro' like 1.5:1 ? No, 1:1 is 1:1 (1x magnification) no matter how much you crop. Originally posted by micl161 - Can I move away a little longer from the subject (like 1.5 X 6" to 9") on the APSC camera and still get the 1:1 photo ? 1:1 is typically available at the minimum focus distance which remains the same regardless of the size of the sensor one is using. If one moves away, one may attain the same framing with APS-C as with 24x36mm FF at 1:1, but at lower magnification (0.67x). The rules are the same as with non-macro lenses. Framing (crop) is not the same as magnification, though it may influence how much magnification is required to attain final display size. Example: If one takes a photo of a metric ruler stretched across the frame at 1:1 using a 24x36 FF camera, the number of millimeter marks visible will be 35 full marks with 1/2 mark at either side. The same ruler at 1:1 on APS-C will show 24 full marks with 0.55 mark at either side (25.1mm). Backing off so that 35 marks show with a 1/2 mark on each side requires only 1:1.5 (0.67x magnification) at capture, but 1.5x more enlargement at print time than the FF image to make a 24x36cm print. Steve Last edited by stevebrot; 06-06-2018 at 09:49 PM.

06-07-2018, 05:56 AM	#8
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,452	The practical impact of all of this is that most of the time the apsc sensor has denser pixels per mm so 1:1 on apsc will have a higher number of pixels on the subject which allows potentially larger enlargements without loss of detail. Last edited by UncleVanya; 06-07-2018 at 06:06 AM.

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06-06-2018, 09:33 PM - 1 Like	#3
Sandy Hancock Moderator Site Supporter Join Date: Feb 2012 Location: Adelaide Hills, South Australia Photos: Gallery \| Albums Posts: 11,275	Strictly speaking, no. 1:1 reproduction means that the image on the sensor is life size. On a crop sensor you therefore get less of it, so when you enlarge it to the same size it looks more magnified. [edit]In other words, what Steve said [/edit]

06-06-2018, 10:04 PM - 8 Likes	#4
swanlefitte Pentaxian Join Date: May 2015 Location: Minneapolis Photos: Gallery Posts: 4,068	Its easier for me to think of 1:1 by visualizing putting the thing i am photographing on the sensor. If i took a coin and pressed it on the sensor that is what the sensor would process. Its actual size. Since the ff sensor is bigger the coin won't take up as much of the sensor as on apsc.

06-06-2018, 10:17 PM	#5
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by swanlefitte Its easier for me to think of 1:1 by visualizing putting the thing i am photographing on the sensor. If i took a coin and pressed it on the sensor that is what the sensor would process. Its actual size. Since the ff sensor is bigger the coin won't take up as much of the sensor as on apsc. Excellent explanation! Steve

06-06-2018, 10:21 PM	#6
swanlefitte Pentaxian Join Date: May 2015 Location: Minneapolis Photos: Gallery Posts: 4,068	Thanks i was puzzled at one time and this thinking is what got me through it.

06-06-2018, 10:21 PM - 4 Likes	#7
Paul the Sunman Pentaxian Join Date: Aug 2011 Location: Melbourne Photos: Gallery Posts: 4,846	Originally posted by swanlefitte Its easier for me to think of 1:1 by visualizing putting the thing i am photographing on the sensor. If i took a coin and pressed it on the sensor that is what the sensor would process. Its actual size. Since the ff sensor is bigger the coin won't take up as much of the sensor as on apsc. However, the novice photographer is advised not to press a coin on their sensor.

06-07-2018, 06:19 AM	#9
LensBeginner Veteran Member Join Date: Sep 2014 Photos: Albums Posts: 4,696	After "equivalent focal length" (?) and then "equivalent aperture" (??), some clever fellow actually came up with "equivalent magnification" I don't remember the details, but the same question was posed on the Italian forum, citing IIRC Olympus website, and the technical specification of some macro lenses, which had confusingly different and strange magnification values, like "2:1 on m43" for a 1:1 lens... So no worries, people who do that for a living get it wrong all the time!

06-07-2018, 06:59 AM	#10
normhead Pentaxian Join Date: Jun 2007 Location: Near Algonquin Park Photos: Gallery \| Albums Posts: 40,451	Originally posted by UncleVanya The practical impact of all of this is that most of the time the apsc sensor has denser pixels per mm so 1:1 on apsc will have a higher number of pixels on the subject which allows potentially larger enlargements without loss of detail. And also sometimes a smaller sensor site camera will capture detail not captured with a camera with larger pixel sites. This almost always favours smaller sensor cameras. IN a practical sense, since most to the time you are enlarging things with macro, you get more effective enlargement with a smaller sensor. There's nothing quite as disappointing as setting up a macro on a K-3 then changing to a K-1 because of light conditions. And I so often shoot close to the minimum focusing distance moving closer is not an option. On a K-1 minimum focusing distance is more likely to become an issue, because it's harder to fill the frame with a small object. I only use the K-1 for macro when I don't have enough light to effectively use the K-3 and I want to push to the K-1 high ISO values. If you have a K-70 or K-P even the isn't much of an issue.

06-07-2018, 08:03 AM	#11
micl161 Senior Member Join Date: Mar 2014 Location: Hong Kong Posts: 127 Original Poster	Thanks for the ruler and coin example, it seems I understand the rule now, but I'm sure I'll get confuse again sooner or later ! Also thanks for pointing out the advantage of APSC when shooting macro, so many to learn..!

06-07-2018, 08:17 AM	#12
BrianR Veteran Member Join Date: Dec 2010 Location: Ontario Photos: Gallery Posts: 3,332	Originally posted by swanlefitte Its easier for me to think of 1:1 by visualizing putting the thing i am photographing on the sensor. If i took a coin and pressed it on the sensor that is what the sensor would process. Its actual size. Since the ff sensor is bigger the coin won't take up as much of the sensor as on apsc. Good explanation. Before I purchased a macro lens I had taken pieces of cardboard and cut rectangles out of them corresponding to the framing I'd get with aps-c at different magnifications. A 16x24mm rectangular with "1:1" label, a 32x48mm hole with a "1:2" label, etc. This let me compare the framing I could get with the macro vs. the lenses I had at their minimum focusing distance. Easy enough to repeat for different sensor formats.

06-07-2018, 08:23 AM	#13
LensBeginner Veteran Member Join Date: Sep 2014 Photos: Albums Posts: 4,696	Originally posted by BrianR Good explanation. Before I purchased a macro lens I had taken pieces of cardboard and cut rectangles out of them corresponding to the framing I'd get with aps-c at different magnifications. A 16x24mm rectangular with "1:1" label, a 32x48mm hole with a "1:2" label, etc. This let me compare the framing I could get with the macro vs. the lenses I had at their minimum focusing distance. Easy enough to repeat for different sensor formats. It's a great idea! A variation could be an A5 sized sheet with the various size printed (I think an A4 is too big for that, you don't need to go all the way to 1:10...), that one could laminate and bring with them. One could also cut it, and get the transparency and resilience from the plastification.

06-07-2018, 08:27 AM	#14
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,452	The Q with a macro lens would be pretty crazy with most subjects!