Macro lenses? at DVinfo.net

Dave Allen · March 10th, 2014, 05:41 PM

If you really wanted to nail tight macro, would use use a fixed length macro lens, considering the subject might be 1-4 feet away, and if so, what mm length, or would you use a zoom lens with an achromatic diopter screwed on, and if so, what zoom strength? I already have a full set of achromatic diopters.

Here's an example of how tight I might want to get:

Olof Ekbergh · March 10th, 2014, 06:03 PM

I have a Canon 100mm f2.8 Macro V1 and it takes wonderful stills and works great with the Metabones adapter on the FS700. The image is very sharp the SDOF is nice and the Boketh (no harsh edges around lights and high contrast OOF objects) is very soft.

Alastair Traill · March 11th, 2014, 04:29 AM

Hi Dave,

A huge advantage in using a zoom lens is that it is much easier to find the subject using a wide-angle setting. However when you start adding close up lenses your ‘infinity’ setting is approximately the focal length of the close up lens in use e.g. a 2 diopter close-up lens gives you an ‘infinity’ distance of ~ 0.5 meter. Your closest distance with a 2 diopter close up lens will probably be around 0.4m depending on your camera lens. This means you have to set your camera to subject distance to somewhere between 0.4 and 0.5 m if focus is to be achieved. As you add stronger close-up lenses the tolerances become even tighter and the depth of field reduces also. All this makes setting up more critical and if your subject is mobile it may move out of range.

A prime macro lens makes it less critical when setting the camera to subject distance as it will give you a greater focusing range. I have several macro lenses including a Nikon 70-170 mm zoom – although it is called a Macro lens it does not reach a 1:1 image at 170 mm. A 1:1 image means that the area covered is equal to the size of your camera’s sensor. If you are using a ¼” or 1/3” sensor at 1:1 you will only cover a portion of your ladybird whereas with a full 35mm frame sensor at 1:1 the ladybird will have room to move within the frame.

There is an advantage using a small sensor for macro work because to achieve to the same coverage you use a shorter focal length lens and thus gain a greater depth of field.

Another problem with macro work is that any unintended camera movement is much more obvious.

March 10th, 2014, 05:41 PM	#1
Dave Allen Major Player Join Date: Apr 2008 Location: Boston Posts: 497	Macro lenses? If you really wanted to nail tight macro, would use use a fixed length macro lens, considering the subject might be 1-4 feet away, and if so, what mm length, or would you use a zoom lens with an achromatic diopter screwed on, and if so, what zoom strength? I already have a full set of achromatic diopters. Here's an example of how tight I might want to get: __________________ Dave -

March 10th, 2014, 06:03 PM	#2
Olof Ekbergh Sponsor: Westside AV Join Date: Dec 2008 Location: Mount Washington Valley, NH, USA Posts: 1,365	Re: Macro lenses? I have a Canon 100mm f2.8 Macro V1 and it takes wonderful stills and works great with the Metabones adapter on the FS700. The image is very sharp the SDOF is nice and the Boketh (no harsh edges around lights and high contrast OOF objects) is very soft. __________________ Olof Ekbergh • olof@WestsideAV.com Westside A V Studios • http://www.WestsideAVstore.com/

March 11th, 2014, 04:29 AM	#3
Alastair Traill Major Player Join Date: Nov 2008 Location: Melbourne Australia Posts: 626	Re: Macro lenses? Hi Dave, A huge advantage in using a zoom lens is that it is much easier to find the subject using a wide-angle setting. However when you start adding close up lenses your ‘infinity’ setting is approximately the focal length of the close up lens in use e.g. a 2 diopter close-up lens gives you an ‘infinity’ distance of ~ 0.5 meter. Your closest distance with a 2 diopter close up lens will probably be around 0.4m depending on your camera lens. This means you have to set your camera to subject distance to somewhere between 0.4 and 0.5 m if focus is to be achieved. As you add stronger close-up lenses the tolerances become even tighter and the depth of field reduces also. All this makes setting up more critical and if your subject is mobile it may move out of range. A prime macro lens makes it less critical when setting the camera to subject distance as it will give you a greater focusing range. I have several macro lenses including a Nikon 70-170 mm zoom – although it is called a Macro lens it does not reach a 1:1 image at 170 mm. A 1:1 image means that the area covered is equal to the size of your camera’s sensor. If you are using a ¼” or 1/3” sensor at 1:1 you will only cover a portion of your ladybird whereas with a full 35mm frame sensor at 1:1 the ladybird will have room to move within the frame. There is an advantage using a small sensor for macro work because to achieve to the same coverage you use a shorter focal length lens and thus gain a greater depth of field. Another problem with macro work is that any unintended camera movement is much more obvious.