Nikon 105mm f2.8 Macro can't shoot at f2.8 at 1:1?

Started Apr 22, 2013 | Discussions
tinchao
New MemberPosts: 1
Like?
Nikon 105mm f2.8 Macro can't shoot at f2.8 at 1:1?
Apr 22, 2013

I was somewhat disappointed to find out my newly purchased Nikon 105mm f2.8 can not shoot at f2.8 at close range. I shoot at f4.8. Only if I move far enough to the subject like 12 feet or so, I can then shoot at f2.8, what is the point of spending all the money for a f2.8 lens.... My friend has Sigma 150mm f2.8, he can shoot at f2.8 at all ranges. I am using a Nikon D7000 camera. Any input? Thanks.

Nikon AF-S Micro-Nikkor 105mm f/2.8G IF-ED VR Nikon D7000
If you believe there are incorrect tags, please send us this post using our feedback form.
Leonard Migliore
Veteran MemberPosts: 9,964Gear list
Like?
I bet your friend has a Canon
In reply to tinchao, Apr 22, 2013

tinchao wrote:

I was somewhat disappointed to find out my newly purchased Nikon 105mm f2.8 can not shoot at f2.8 at close range. I shoot at f4.8. Only if I move far enough to the subject like 12 feet or so, I can then shoot at f2.8, what is the point of spending all the money for a f2.8 lens.... My friend has Sigma 150mm f2.8, he can shoot at f2.8 at all ranges. I am using a Nikon D7000 camera. Any input? Thanks.

This is how all lenses are. As you focus closer, the true f/stop increases. For unit-focusing lenses, when you go to 1:1 you lose 2 stops. So an f/2.8 lens focused to 1:1 will be f/5.6. The 105mm Nikkor loses focal length as it focuses closer so it does not have quite this much loss.

The difference between Nikon and Canon is that Nikon reports the effective aperture and Canon does not. So I can rack my MP-E65 out to 5X and it still reads f/2.8 even though it's actually around f/11.

-- hide signature --

Leonard Migliore

 Leonard Migliore's gear list:Leonard Migliore's gear list
Canon PowerShot G12 Nikon D300 Nikon AF-S DX Nikkor 16-85mm f/3.5-5.6G ED VR Nikon AF-S DX Nikkor 35mm f/1.8G Nikon AF-S DX Nikkor 10-24mm f/3-5-4.5G ED +9 more
Reply   Reply with quote   Complain
KCK14
Regular MemberPosts: 400Gear list
Like?
Re: I bet your friend has a Canon
In reply to Leonard Migliore, Apr 23, 2013

Its physics.  The lens is f2.8 at infinity.  As it is extended, the effective aperture gets smaller.  All macro lenses do this forever.

 KCK14's gear list:KCK14's gear list
Panasonic Lumix DMC-LX5 Nikon D90 Olympus OM-D E-M5
Reply   Reply with quote   Complain
sherwoodpete
Veteran MemberPosts: 7,761
Like?
Re: I bet your friend has a Canon
In reply to KCK14, Apr 23, 2013

KCK14 wrote:

Its physics.  The lens is f2.8 at infinity.  As it is extended, the effective aperture gets smaller.  All macro lenses do this forever.

A matter of terminology.

In the way I learned those terms, the "effective aperture" remains the same. It is the "relative aperture" which changes.

(unless there are overlapping but contradictory definitions depending on the source of the information).

Reply   Reply with quote   Complain
Guidenet
Forum ProPosts: 12,436Gear list
Like?
Normal behavior for Macro lens photography
In reply to tinchao, Apr 23, 2013

tinchao wrote:

I was somewhat disappointed to find out my newly purchased Nikon 105mm f2.8 can not shoot at f2.8 at close range. I shoot at f4.8. Only if I move far enough to the subject like 12 feet or so, I can then shoot at f2.8, what is the point of spending all the money for a f2.8 lens.... My friend has Sigma 150mm f2.8, he can shoot at f2.8 at all ranges. I am using a Nikon D7000 camera. Any input? Thanks.

As others have said, this is the way all macro lenses work. I too have the Sigma 150 f/2.8 which I think is a better lens, by the way, and it also loses effective speed as I approach 1:1 close focusing. My Nikon's show this loss. Please read the manual.

Understand how a macro lens works, or all lenses for that matter. As you focus out to infinity, the lens elements move closer to the focal plane (film or sensor). As you focus closer, the lens elements move farther away. Macro lenses have to focus very close and therefore move very far from the focal plane. This is why extension tubes and bellows work to focus closer. The lens is moved farther from the sensor.

Now, as you move this elements of the lens farther from the focal plane, you're creating a long, dark tube the light has to travel down. Not as much light makes it to the sensor. It works the same way when you add an extension tube, teleconverter, or anything else between the lens and camera. You lose light. Nikons report this loss, showing you the effective f/stop. Some cameras, you have to calculate it yourself. Regardless, it's a fact of life. You still have an f/2.8 lens. You didn't get ripped off.

As you approach 1:1 close focusing, things become more of a manual focus on a tripod game. VR or other stabilization methods become ineffective too. You're just getting too close. Most macro shooters find it handier to mount the camera and lens on a focusing rail. You mount that rail on a tripod head and set your lens on manual focus and then move the camera via the rail in and out to achieve focus using liveview or the optical viewfinder.

Good luck and have fun.

-- hide signature --

Cheers, Craig
Follow me on Twitter @craighardingsr : Equipment in Profile

 Guidenet's gear list:Guidenet's gear list
Nikon D300 Nikon D700 Nikon D3S Nikon D800 Nikon AF-S DX Nikkor 18-135mm f/3.5-5.6G ED-IF +24 more
Reply   Reply with quote   Complain
Bjorn_L
Veteran MemberPosts: 4,457Gear list
Like?
aperture at 1:1 should seldom be wide open
In reply to tinchao, Apr 23, 2013

tinchao wrote:

I was somewhat disappointed to find out my newly purchased Nikon 105mm f2.8 can not shoot at f2.8 at close range. I shoot at f4.8. Only if I move far enough to the subject like 12 feet or so, I can then shoot at f2.8, what is the point of spending all the money for a f2.8 lens.... My friend has Sigma 150mm f2.8, he can shoot at f2.8 at all ranges. I am using a Nikon D7000 camera. Any input? Thanks.

Your DOF will be VERY thin at 1:1 even at f/5.  Most of the time you are shooting 1:1 you will want to stop it down to f/8 or more.  Most macro photos I've seen are in the f/11-16 range with some running in to the diffraction zone (f/22 for example) for more DOF.

-- hide signature --

See my plan (in my profile) for what I shoot with. See my gallery for images I find amusing.

 Bjorn_L's gear list:Bjorn_L's gear list
Panasonic Lumix DMC-TZ5 Canon PowerShot SX30 IS Nikon D700 Nikon AF-S Nikkor 70-200mm f/2.8G ED VR Nikon AF-S Nikkor 50mm f/1.4G +9 more
Reply   Reply with quote   Complain
Thorbard
Contributing MemberPosts: 677Gear list
Like?
Re: I bet your friend has a Canon
In reply to Leonard Migliore, Apr 23, 2013

Leonard Migliore wrote:

This is how all lenses are. As you focus closer, the true f/stop increases. For unit-focusing lenses, when you go to 1:1 you lose 2 stops. So an f/2.8 lens focused to 1:1 will be f/5.6. The 105mm Nikkor loses focal length as it focuses closer so it does not have quite this much loss.

The difference between Nikon and Canon is that Nikon reports the effective aperture and Canon does not. So I can rack my MP-E65 out to 5X and it still reads f/2.8 even though it's actually around f/11.

-- hide signature --

Leonard Migliore

I agree, but I would call what Canon reports the "nominal" aperture.

 Thorbard's gear list:Thorbard's gear list
Canon EOS 7D Canon PowerShot G15 Canon EF 85mm f/1.8 USM Canon EF-S 15-85mm f/3.5-5.6 IS USM Canon EF 40mm f/2.8 STM +1 more
Reply   Reply with quote   Complain
Leonard Migliore
Veteran MemberPosts: 9,964Gear list
Like?
That's what Kodak called it
In reply to sherwoodpete, Apr 23, 2013

sherwoodpete wrote:

KCK14 wrote:

Its physics.  The lens is f2.8 at infinity.  As it is extended, the effective aperture gets smaller.  All macro lenses do this forever.

A matter of terminology.

In the way I learned those terms, the "effective aperture" remains the same. It is the "relative aperture" which changes.

(unless there are overlapping but contradictory definitions depending on the source of the information).

Back in the dark ages of manual exposure, you could purchase an "Effective Aperture Kodaguide" that gave you the corrected f/stop as you racked out for close focus. So that's where I got the term.

-- hide signature --

Leonard Migliore

 Leonard Migliore's gear list:Leonard Migliore's gear list
Canon PowerShot G12 Nikon D300 Nikon AF-S DX Nikkor 16-85mm f/3.5-5.6G ED VR Nikon AF-S DX Nikkor 35mm f/1.8G Nikon AF-S DX Nikkor 10-24mm f/3-5-4.5G ED +9 more
Reply   Reply with quote   Complain
Keyboard shortcuts:
FForum MMy threads