lamiaceae Loc: San Luis Obispo County, CA

I have actual Macro lenses but the question concerns a special use of diopter rated filters. Say I have a 135mm lens, what diopter filter, say +1, +2, +3, etc. do I need to double the magnification or half it's working distance? I know 1 diopter means a focal length of 1000mm, but how do I use that fact? Since my lens has a 67mm front size I would rather but just one correct filter for my needs than the usual set of three filters, 1, 2, 4 or 1, 2, 3. Or to be able to shoot the 135mm at 1:1?

The explanations I read online mainly define what diopter values are but not how to use them for a use.

Architect1776 Loc: In my mind

This will be interesting.
I would guess that due to these diopters fitting multiple focal length lenses with different capabilities there are a wide range possible answers.

Brian in Whitby Loc: Whitby, Ontario, Canada

I used to use them. Usualky, I eould just put one on the lens and see if I got the magnificarion I wanted. As I gained experience I was able to guess which lens I wanted. With 50 mm lens, I found that anything more thsn +3 was just too short a working distance for anything I wanted to shoot.
I hope this helps even if it is not the answer you were looking for.
PS: You might also consider extension tubes. There are generic ones for most common cameras that maintain the electrical connections between camera and lense so auto focus and a aperture contro ln are maintained.

blackest Loc: Ireland

They are kinda like reading glasses a 1 diopter has a maximum focus distance of 1 meter a 2 is 1/2 meter a 3 is 1/3 (33cm) 1/4 25cm a 1/2 diopter would be 2 Meters and rare there is another kind of half diopter which is a half a diopter lenses. giving two planes of focus it can tricky to hide the join.

bleirer

This seems to address your question. I'll have to read more carefully though. Looks like a diopter is 1000 divided by focal length.

https://pages.mtu.edu/~shene/DigiCam/User-Guide/A95/Close-Up/Close-Up-Lenses.html#:~:text=Most%20close-up%20lenses%20are,the%20lens%20measured%20in%20mm.&text=Thus%2C%20the%20250D%20and%20500D,%3D%201000%2F500%2C%20respectively.

imagemeister Loc: mid east Florida

Simply put, a +1 diopter turns your infinity focus to 1 meter , a +2 to 1/2 meter ect.

In your case, Canon makes the 500D (+2 diopter) and the 250D (+4 diopter) high quality 2-element CU lenses. The 250D should get you fairly close to 1:1 . BUT, Canon does NOT make them in 67mm size - so you will have to use adapter rings. Keep in mind the higher the power of the CU lens, the lesser the IQ. Marumi also makes 2-element lenses if you can find them.
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RWR Loc: La Mesa, CA

I have made complete tables with various diopter close-up lenses on prime lenses from 50mm to 150mm, including subject distances, working distances, magnifications, &c. Unfortunately, I have no experience with close-up filters.

lamiaceae Loc: San Luis Obispo County, CA

OK, thanks for some comments and suggestions but that so far it is either stuff I already know too well, or not answering my specific question about putting a close-up filter on a 135mm lens. Wanting to know exactly what resultant magnification I get with say a 3 diopter (333mm) close-up filter on the 135mm lens, i.e., the resultant combination magnification and working distance. Oh, and the reason for wanting to use close-up a filter on this lens is that it is a "digital lens" and has no mechanical click-stops and the Extension Tubes I have have no electronic camera-lens coupling, only allowing stop-down use with my other lenses that do have mechanical operated irises. Not really wanting to take images at f/2.8 with a 1:2.8 Lens. Let me get some breakfast into me and I'll give you more details and what I think thus far.

bleirer

I'm pretty sure close up lenses and close up filters are the same thing with a different name. They all screw onto the filter threads, no?

imagemeister Loc: mid east Florida

imagemeister Loc: mid east Florida

Can you show us ??
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RWR Loc: La Mesa, CA

Of course, but I’m not home at present - may not be til later today or in the morning.

lamiaceae Loc: San Luis Obispo County, CA

That is what I was referring to. There are I here fancier doublets and triplets that are really considered "lenses" that screw on to the front of a lens for making changes in magnification but that is not what I'm asking about, just the simple one element diopter filters.

lamiaceae Loc: San Luis Obispo County, CA

Yes, that would be interesting. I would like to see it as well.

lamiaceae Loc: San Luis Obispo County, CA

I think over my replies and further explanation I think most everyone has a good idea of what I am asking now. I actually have a lot of experience and knowledge about close-up photography and macro photography, just not a lot from using close-up filters. From my film photography days I have a lot of "close-up" and "macro" equipment: (for both Pentax K and Screw Mount) 4 sets of Extension Tubes, 2 Bellows, Reverse Lens Adapter Rings, even a coupler for mounting two lenses front to front, 5 actual Macro lens. And I have a set of 49mm diameter Close-up filters.

But I would like to buy just one high quality Schneider brand 67mm diameter Close-up filter/lens for my new smc-Pentax DA* 50-135mm 1:2.8 ED [IF] SDM lens. My reason for much of this because it has Internal Focusing (rare for a Pentax lens), and I think that would be great for focus stacking but the lens has no click stop ring and so extension tubes are virtually out of the question. So I asking asking so I could figure out what single one diopter filter I could use.

After doing more research reading, and doing some experiments using another but prime old film 135mm lens and photographing a mm ruler with various close-up filter combinations (magnifications) of +7, +4, +3, & +2 diopter on the lens, I conclude that what would work best for me would be a +2.5 diopter filter, but seeing as that does not seem to exist I have decided to buy a 2 Diopter 67mm diameter Schnieder filter from B&H. I eventually worked out the math I was hoping to get help discovering. Thanks for the discussion I did receive.

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