Nikon CFI60 infinity-corrected objective and Raynox

Craig Gerard · Post by **Craig Gerard** » Tue Nov 30, 2010 8:01 pm

Nikon CFI60 infinity-corrected objective and Raynox.

On page 2 of the thread (link below), Joaquim mentions the use of a Raynox DCR-150 as a tubelense for the Nikon CFI60 10X.

'Infinity objective on low-end zoom telephoto works fine'
http://www.photomacrography.net/forum/v ... php?t=9664

Joaquim wrote:Another good candidate, probably in the bag of many of the forum participants, is the Raynox DCR-150 macro conversion lens, a 210mm (+4.8 diopters) achromatic triplet with about 35mm lens diameter.

I have attached the Nikon CFI60 10X to a DCR-250 (125mm) and a focusing helicoid. Initial indications are very encouraging at various magnification.

I also have the Raynox MSN-202, but don't have a DCR-150...yet.

I will upload some images.

There must be other members looking at this combo?

Advice, suggestions, requests....?

Craig

Bob^3 · Post by **Bob^3** » Wed Dec 01, 2010 11:14 am

Craig, watching with interest. I've been considering purchasing the appropriate tube lenses from Edmund Scientific. But those are a bit expensive and the Raynox diopters come in more focal lengths.

I think this could be the way to make a very small package which fully utilizes the available image circle of the infinity-corrected objectives, without vignetting. I'd be interested in knowing the lowest magnification you can get with this combo.

I also have focussing helicoids (Chinese made long and short versions)---but no Raynox lenses yet. Where are you mounting the Raynox, near the camera or the objective? I think Rik stated that it shouldn't matter for IQ, but it may for maximizing the image circle.

rjlittlefield · Post by **rjlittlefield** » Wed Dec 01, 2010 1:22 pm

Bob^3 wrote:Where are you mounting the Raynox, near the camera or the objective? I think Rik stated that it shouldn't matter for IQ, but it may for maximizing the image circle.

I hope I didn't say exactly that. For best IQ, the Raynox must be mounted at one of its own focal lengths from the sensor, so that it focuses at infinity. It is separation between objective and Raynox that may change the image circle but not the IQ.

--Rik

Bob^3 · Post by **Bob^3** » Wed Dec 01, 2010 1:35 pm

rjlittlefield wrote:I hope I didn't say exactly that. For best IQ, the Raynox must be mounted at one of its own focal lengths from the sensor, so that it focuses at infinity. It is separation between objective and Raynox that may change the image circle but not the IQ.

Yes, that is a more precise version of what I remember. Sorry for not completing the concept.

This is a perfect occasion to use my new favorite phrase "please read what I meant to write, rather than what I did!"

...Courtesy I think of Craig Gerard?

Bob^3 · Post by **Bob^3** » Wed Dec 01, 2010 1:57 pm

However, I will add that, based on tests with limited extension using prime Nikon lenses as a tube lens, I think there may be some tolerance in the position of the tube lens relative to the sensor---depending on the dimensions and pixel pitch of the sensor.

Craig Gerard · Post by **Craig Gerard** » Wed Dec 01, 2010 6:51 pm

Bob,

That's not my quote. It was in a recent post, I went looking but haven't found it yet...

I have the Raynox attached to an adjustable 35-90mm M42 helicoid. The Raynox universal adapter does not go down to M42, so I added an M42 to 52mm step ring to the helicoid and then a 52mm to 58mm step ring (whatever was handy). I intend to replace the Raynox universal adapter with an appropriate step ring (for neatness

); but for now the universal adapter works fine.

The CFI60 is attached to the jinfinance CFI adapter (terminates in male 52mm thread), which in turn is attached to a 49mm to 52mm step adapter. The 49mm thread screws into the filter thread of the Raynox DCR-250. The Raynox universal adapter attaches to the 58mm ring mentioned in previous paragraph. The CFI 60 10X is attached as close to the Raynox as my current steps rings permit.

Will upload an image of the setup and some examples of the results. (I've just received a package from Sweden that I am looking forward to opening)

Craig

Bob^3 · Post by **Bob^3** » Wed Dec 01, 2010 7:58 pm

That's not my quote. It was in a recent post, I went looking but haven't found it yet...

I finally remembered. It was actually my rephrase of ChrisR's caution regarding his ray diagram, complete with creatively dressed bug:

http://www.photomacrography.net/forum/v ... eant+write

I do love dry British humor!

I have the Raynox attached to an adjustable 35-90mm M42 helicoid.

I also have a 35-90mm helicoid with M42 on the front and Nikon F on the camera side---and the jinfinance adapter. So your setup should translate directly to mine, once I decide which Raynox lenses to buy.

Enjoy your early Christmas gift from Sweden!

Craig Gerard · Post by **Craig Gerard** » Fri Dec 03, 2010 6:01 am

Here's the first example; I have many others; but I am trying to determine the best place in the optics chain for the Raynox DCR-250 (any suggestions...125mm from sensor?).

The image below is 190mm from sensor to objective thread. The CFI60 10X objective in this example is as close to the DRC-250 as my adapters will allow. I'm inclined to move the Raynox further away from the objective, just to see the result.

I don't know what that greenish tint is on the right side?

Do you think it is worthwhile pursuing this any further?

Craig

ChrisLilley · Post by **ChrisLilley** » Fri Dec 03, 2010 8:48 am

Craig Gerard wrote: I don't know what that greenish tint is on the right side?

If you tilt the graduated slide a little, do you get more green in the parts that are further away than the plane of sharpest focus, and magenta in the parts that are closer?

ChrisLilley · Post by **ChrisLilley** » Fri Dec 03, 2010 8:53 am

Craig Gerard wrote:Here's the first example; I have many others; but I am trying to determine the best place in the optics chain for the Raynox DCR-250 (any suggestions...125mm from sensor?).
Craig

DCR-250 is a +8 diopter so the focal length is 1000/4.8 = 125mm. So, yes, that should give an infinity-focussed 125mm tube lens. I guess you could verify that by taking a photo on a tripod out the window of some distant object (just the raynox, no objective) and seeing if it is sharp.

Craig Gerard · Post by **Craig Gerard** » Fri Dec 03, 2010 5:43 pm

Chris,

When using the Raynox with the focusing helicoid it focuses on infinity at approx 125mm from the sensor. The resulting image is soft, as you would expect; but it's an image nonetheless.

Craig

*edit: typo

Craig Gerard · Post by **Craig Gerard** » Fri Dec 03, 2010 5:45 pm

I've now positioned the Raynox DCR-250 40mm from the objective and added the CFI60 10X.

The image below is 160mm from sensor to objective shoulder.

The image below is 210mm from sensor to objective shoulder.

Here is 100% pixel crop from the image above, looking at the CA aspect.

The image below is 125mm from sensor to objective shoulder.

Craig

Craig Gerard · Post by **Craig Gerard** » Fri Dec 03, 2010 7:43 pm

Here's the finite CF N 10X @ 160mm from objective shoulder to sensor (no Raynox used for this image).

It tells me one thing that may help when viewing/assessing the earlier images; my setup is still not level.

I'll let someone else do the magnification number crunching.

Craig

Craig Gerard · Post by **Craig Gerard** » Fri Dec 03, 2010 11:49 pm

After spending some time using a Raynox DCR-250 as a tubelense, I went back to using the Canon EF f/4 70-200mm L USM with the Nikon CFI60 10X.....at first comparisons, the Raynox DCR-250 is providing a much higher quality image..

Ideally, the Raynox DCR-250 should be located and fixed 125mm from the sensor, with the CFI60 10X positioned somewhere between 140 and 200mm (maybe more) from sensor plane, it seems to play well in this region.

By the way, if the Raynox DCR-150 is (250mm) and the Raynox DCR-250 is (125mm), what is the Raynox MSN 202 ( ? mm)

Now, I'm going to revisit the EF 70-200 L USM and try and work out why it is not delivering similar clarity and lack of CA equivalent to the Raynox.

*This is an ongoing project, I reserve the right to change my opinion

Craig

rjlittlefield · Post by **rjlittlefield** » Sat Dec 04, 2010 12:25 am

Craig Gerard wrote: what is the Raynox MSN 202 ( ? mm)

At http://www.raynox.co.jp/english/video/hdrfx7/index.htm, the MSN-202 is described as "25-Diopter". That would make it 1000/25 = 40 mm focal length.

Now, I'm going to revisit the EF 70-200 L USM and try and work out why it is not delivering similar clarity and lack of CA equivalent to the Raynox.

I wish you luck with that part about "why". See HERE for some discussion about issues with lens combos, which is what we're really talking about when we stick an infinity objective in front of a telephoto lens.

It would be very helpful to simply nail down the "what". If you can demonstrate for sure that the CFI60 objective combined with the EF 70-200 L USM gives CA, while it does not when used with the Raynox, that would be a valuable contribution. To date, no one has documented a combination that does not work well. It would be ironic, but helpful, to know that combining one of Canon's finest telephotos with one of Nikon's finest objectives gives an inferior result.

--Rik