Hasselblad Proxar Filters VS 120mm Macro

[Dave Son]

Hi all,

not so long ago I bought some Hasselblad Proxar filters (mainly to use with my 150mm but also my 80mm) as a cheap solution for doing some macro work. Prior to buying these filters I’d never done any macro photography before and so I was very surprised to find that all my results so far have had a razor thin depth of field! In some cases this was intentional but other times I’ve shot at apertures like f.11 and have still had crazy shallow DOF. This is not always the look that I want and I’m wondering how I can achieve greater depth of field in my macro shots.

I’m in the midst of trying to figure out whether investing in a 120mm makro planar would resolve this issue for me; is it possible to achieve greater DOF with a dedicated macro lens like this or are all macro solutions for this camera going to be tied up with unavoidable shallow DOF?

Any advice on this would be much appreciated.

Many thanks,

Dave

 

[cramej]

Depth of field is a function of subject distance, aperture and focal length so depth of field doesn't significantly change with a different lens of similar focal length with or without closeup lenses like the Proxars. I don't know Hasselblad that well, but the 120mm would optimized for close focus rather than infinity and possibly has a closer minimum focus distance. Depth of field preview is immensely helpful when shooting macro.

 

[film_man]

If I am not mistaken (please somebody correct me if I am) the way this work is:

A 50mm lens focused at 1m gives you magnification X.
A 100mm lens focused at 2m gives you the same magnification X.

A 50mm at f/2 has a 25mm aperture.
A 100mm at f/4 has a 25mm aperture.

So, a 50mm at f/2 at 1m will give you the same magnification and depth of field as a 100mm at 2m and f/4. The background view will be different due to the different angle of view and obviously the working distance is a practical factor but subject magnification and depth of field should be the same.

A close-up filter simply allows you to focus closer, getting a longer lens that will get you the same magnification from a longer distance will make no difference to depth of field.

If you use a 120 at its min focus of 0.8m and you use a proxar on the 80 to get to the 0.8m then all you are gaining is a bit of practicality and obviously some image sharpness as the 120 is optimised for macro vs the 80 with a random piece of glass in front of it.

In general, things get very blurry outside the focus plane once you get to 1:4 or closer.

 

[Dave Son]

Great, many thanks for the advice. The 120mm Makro would definitely be a bit more convenient and practical to use but very useful to know that it won’t resolve my issue at all so probably won’t be worth the investment for me.

 

[MattKing]

If you are looking for more depth of field, smaller formats actually work better.
It is probably safe though to go to f/16 or even f/22. The effects of diffraction are real, but manageable.

 

[Sirius Glass]

OR the 135mm lens with the variable extension tube which may be more flexible for you.