Macro with the G7X : magnification

This is very helpful. Let me ask a few questions to make it even more helpful:

1. What is "CPL"?

2. How did you get the +4 diopter to adhere to, or attach to, the lens of the G7X? What are the "third party solutions" that  you used?

3. How sharp were the results for the smallest object (c.31mm) with the +4 diopter lens? Was it sharp enough to use it to digitize slides?

We are very interested your results and would like to try this ourselves, but we need your help in telling us what you did and how you did it, in a bit more detail,  and how well it worked in terms of sharpness.

Thanks,

Krugman

krugman wrote:

This is very helpful. Let me ask a few questions to make it even more helpful:

1. What is "CPL"?

2. How did you get the +4 diopter to adhere to, or attach to, the lens of the G7X? What are the "third party solutions" that you used?

3. How sharp were the results for the smallest object (c.31mm) with the +4 diopter lens? Was it sharp enough to use it to digitize slides?

We are very interested your results and would like to try this ourselves, but we need your help in telling us what you did and how you did it, in a bit more detail, and how well it worked in terms of

sharpness.

Thanks,

Krugman

CPL stands for Circular Polarizer filter. See Wikipedia or CambridgeInColor for details. Very helpful : much more than corner sharpness for the impact of an image.

I attach filters with the Magfilteradapter ring. There is also the cheaper Lensmate system, depending on your own needs.

About sharpness, I cannot tell with the G7X because actually, I performed very quick tests only to measure size objects, with a very little care about sharpness, and handled. Needless to say that with a light camera such as the G7X and a +10 filter of the longer FL, you need very steady hands !

But in general, such filters work well and retain a good amount of sharpness. Even with very basic filters, one can achieve very decent results. Kurt Munger studied close-up cheap kits. The filters I own are Hoya HMC Close-up +4 and Hoya 55mm Macro Close-up +10.

Not sure whether a compact camera with such filters can rival a scanner for films or slides. But for sure, you would need a way to handle the film and the camera so that nothing moves, and I don't own such a thing. Indeed, to make sure that everything is in focus, depending on the lens field curvature, you might need to close the lens and lower the shutter speed.

Note : the 31mm size is with the +10 diopters filter, not the +4. And it is on the full tele end. In such a situation, you will undoubtly need a solid tripod or such.

The original post is about max magnification but this is not the whole story. Indeed, a large magnification is sweet, but it is much better if it can be achieved from a reasonable shooting distance.

And while close up lenses permit to decrease the minimal focusing distance, they also decrease a lot the maximal focusing distance.

+10 diopters @100mm

+10 diopters @100mm / max magnification eg closest possible focusing distance @100mm with the +10 diopters filter attached

Again @100mm +10 diopters. The *maximal* focusing distance is very close from the minimal one. So, you don't have very much versatility for composing.

To get an real world idea of the working distances...

Minimal focusing distance @100mm +10 diopters

Maximal focusing distance @100mm +10 diopters : not that much different. The range is indeed very small.

+4 diopters @100mm

With the +4 diopter filter, you loose magnification, but you gain a lot of versatility wrt magnification, while retaining comparable working distances.

@100mm + 4 diopters : max magnification

@100mm + 4 diopters, min magnification

Without a close-up filter

Let me recall magnifications without a close-up lens, @100mm...

Max magnification @100mm without a filter

Max magnification @100mm without a filter

By reducing the FL, it is possible to increase magnification

Max magnification @50mm without a filter

...but you need te be much closer.

Max magnification @50mm without a filter

+4 diopters @50mm

@50mm +4 filter : max magnification

@50mm +4 filter : min magnification

with the following working distances

@50mm +4 filter : max magnification

@50mm +4 filter : min magnification

+10 diopters @50mm

@50mm +10 filter : max magnification

@50mm +10 filter : max magnification

With the +10 filter, wrt to the first sample of this post, by reducing the FL, you regain a fair amount of versatility while keeping a fair amount of magnification (actually better than @100mm with the +4 filter). But you need to get quite close to your subject.

@50mm +10 filter : max magnification

@50mm +10 filter : min magnification

Conclusion

All in all, I think that the +4 filter is appropriate to carry in a pocket everywhere, for quick and casual close-up shots. The +10 will be better suited when you'll have a little more time and specifically intend to shoot close-up.

Sorry for beeing long. I don't expect answers, actually. The point is that this is the kind of information that I've been looking for, but that I couldn't find by Googling. So I hope that it can help future Google searchers. It's not a post meant for "debate".

PS : a Playmobil toy is approximately 7.5 cm (3 inches).

Thanks for the examples, that helps a lot!

Wow! Fantastic information.

I shoot small objects and often look for such information and comparisons. I sense you've done plenty of work for this post. Thank you.