Help!!!!

Hello Experts,

I have one question to you all. I found that usually everyone is talking about diopters

in terms of +2 or +4 etc. ... I was able to aquire a original Canon closeup-lense, the

58mm Close-up Lens 500 D. My problem is now that I was not able to find out wether

it is a +4 or +2.

Canon offers also the 500 and 250 D. Does anyone know how to match these?

Thanxx, Andi

I've been wondering that myself Andi. I know that Canon recommends the 250D for shorter focal length lenses (up to 70mm?) and the 500 / 500 D for longer (above 70mm?), but in terms of the "+" rating, I haven't figured that out.

The difference between the 500 and the 500 D is that the 500 is a single layer construction, which in this case supposedly makes it inferior.

Here is are some facts from it's manual for everyone to enjoy.

Maybe someone knows the math to convert it into the common

+1 / +2 / +3 / +4 rating....

So for 100mm Macro...

with the 500D or 500 the magnifigation is 1.21 ~ 0.20

with the 250D the magnifigation is 1.41 ~ 0.41

with the 500D or 500 the Field of View is 120x180 ~ 20x30

with the 250D Field of View is 59x88 ~ 17x25

Well according to my interopretation, I should have

picked the 250D to make small things bigger and to be able

to get even more close... Or am I wrong? ...

---

Tom just told me he wants to use it on his 70-200 f/2.8L

I also got some values for this lense from the chart:

250D not available

500D or 500 the magnifigation is W: 0.22~0.16 T: 0.52~0.39

I also have values on Field of View in "mm" but their

are many values, due to the zoom issue guess. I will

post if it's of interest.

As far as I know, the 250D is +4 (+4.2 actually) while the 500D is +2. The numbers 250 and 500 refer to the working distance in millimetres of the lens/dioptre combination when focussed on infinity.

Here is a nice explanation of diopters: Diopter Focal Lengths and Powers. Conversions are explained there.

I believe +4 and +2 are the right numbers. The D versions are achromats. Achromats have two lens elements with different difraction properties that help reduce chromatic aberrations. They are more desirable at longer focal lengths. The 500 is a single element diopter.

Craig - Thanks! This page is excellent!

So if you put 1,000/Canon Number, then you get the "+ Number."

So a +1 diopter will cut your furthest focus from infinity to 1 meter. That's probably a good start for macro, maybe a +1.5 or +2 at the max...

Cheers

James

Well we will see how it performs with the Canon 100mm macro lense underwater.

Also it will be nice to have a direct comparision to the Nikon D100 using 105mm.

You will know more on the 16th September 2003 when we are back. Just 9 days

left till we leave. I am already so exited to see the macro challenge and also have

the Canon 10D using SIGMA 15-30mm compared to Nikon D100 using their 12-24mm.

I think a question many of us had already. However as we are many digital divers

on the boat expect also different answers

When is Eric coming back?

So if you put 1,000/Canon Number, then you get the "+ Number."

 

So a +1 diopter will cut your furthest focus from infinity to 1 meter.  That's probably a good start for macro, maybe a +1.5 or +2 at the max...

 

Cheers

James

Very handy, eh?

Well that is a formula I like!!!

Mhh... so as we have solved this I wonder if the additional

investment in an orginal Canon close-up lense will turn out

worthy. I paid around 30 EUR more for it than for a Hoya or

B&H +2 diopter.

But I thought I want only the best for our first original Canon

lense. Since the SIGMA 105mm was also in our consideration.

Do you guyz think I made mistake?

I was reliefed to hear that it features a premium glas...

No, I don't think you made a mistake.

I'm certain the Canon diopters are high quality and the D versions will be better for macro than the single element ones like you mention. I've even put them on Nikon lenses and Sony camcorders without rejection.