Dandelion Lens Emulator

[jebir]

Dandelion Lens Emulator chip

This is a quickie review of my brand new Dandelion lens emulator chip. These chips are made in Russia and will allow you to utilize the AF confirmation signal in the E-system bodies. According to the manufacturer, it won't work with the E-1 which I also confirmed myself. Each chip is ordered for a particular focal length with the idea of enabling Image Stabilization in bodies equipped with that feature. Mine was ordered for 135 mm and the tests in this article were made with an E-510 body.

I ordered my Dandelion Chip from e-bay seller: "volhacd", auction # 120181214577 and paid €40 plus shipping from Germany. The money were wire transfered with IBAN at a cost of €0.25 without problems.

The Good (part I):
I recieved the Dandelion chip today. It was delivered with a tube of cyanoacrylate glue, an extra piece of plastic to support the chip from behind (as tallpe showed in one of his posts), and glueing instructions (identical to those presented above).
Glueing was fiddly to say the least, mainly becayse the curvature of the chip was a bit too large to fit in the adapter (Olympus MF-1). Before I discovered that problem and amended it, I managed to glue the chip hard to my fingers a couple of times and I even glued my fingers together more than once...
Nevermind, after some gentle filing and practising the chip magigally stuck exactly at the right place. That was the end of the Good (part I)

The Good (part II):
The AF confirmation works for the following lenses:

• Tamron SP 17/3.5
• OMZ 35/2.8
• OMZ 50/1.8
• Vivitar Series 1 135/2.3
• Tokina AT-X 300/2.8

Also, the AF confirmation works with an EL-Nikkor 75/4 on a bellows extended about 20 cm.
I managed to get the AF confirmation to work with the Tamron 350/5.6 in very strong light.

(I could not test it with my Rubinar 500/5.6 or Peleng 8/3.5 because I couldn't find the OM-adapter for those lenses)

NOTE: The camera body must be set to MF mode. Otherwise the symptom will be that the Dandelion lens emulator looses contact with the body very quickly ond the lens(chip) must be reset by pressing the lens release button. This confused me a lot initially and I couldn't get the chip to work properly

The Good (part III)
My Dandelion chip was designed to give Image Stabilization with 135 mm focal length (this has to be specified upon ordering) and it works (after "breaking-in" the emulator) reasonably on my E-510. For me, with my Vivitar Series 1 135 mm f/2.3 lens, the effect is most apparent when the exposure time gets longer than 1/10 of a second. However, the IS not att al as effective as what is achieved with the ZD 50-200 at the same focal length and exposure time.

The Bad:
The AF confirmation does not work with

• MTO11-SA 1000/10
• Vivitar 2x macro teleconverter + OMZ 50/1.8

As one of the chip inventors commented, this is a limitation of the camera's AF system - not the Dandelion chip itself.


Usefulness:
Well, the Dandelion chip certainly helps achieving focus with some MF lenses. However, I find it quite distracting to have to pay attention to the AF diode, to the right in the viewfinder, while I want to see that the AF-point is aimed at the relevant part of the subject. I have been using a Katz Eye Optics Plus focusing screen with "HiLux" treatment for two years in one of my E-1s and it is still unbeaten. I'd choose a good bright µ-prism screen in the E-510 any day before the Dandelion chip but then such a screen is also 3x the cost.

The IS works reasonably but it is not as effective as when using a corresponding Zuiko Digital lens. Unfortunately, that reduces the usefulness of the Dandelion lens emulator for this purpose unless your ZD alternative is very slow (like a kit lens) and you have a very fast manual focus lens you can use instead.

This was just a test since I already had that 135 mm lens and the plan was, in case of a 100% successful test, to acquire a Zeiss 85/1.4 ZF and a Dandelion chip to go with it. That could be the ultimate black-cat-in-coal-cellar buster on an E-3. However, with the IS working so-so with the Dandelion, the 1.5 stops advantage (over the ZD 50-200) of the Zeiss lens seems to have been eliminated. I'm still considering the Zeiss 85/1.4 + Dandelion combination though but mostly for the legendary sharpness and bokeh of that lens.

I'm in general pretty happy with the chip although it isn't the revolution I was hoping for.

Cheers, Jens.

UPDATE:
I have now had time to play a lot more with the Dandelion chip (ver. 1.0 - there is now a ver. 2.0 out) and I have to add an important issue:
I have found that, upon focusing my 135/2.3, the focusing LED comes on with a significant delay upon getting to the focused position. Also, there is a corresponding delay upon leaving the focused position. So, one must focus very slowly to be able to pinpoint the focus. If one turns the focusing ring too fast, the LED indicates focus after I have passed the optimum setting. It reacts more swiftly with for example my 300/2.8 or my 50/1.8 was it obviously has something to do with the optics.

[Johnmcl7]

Thanks for the write up, it's interesting to see some proper detail and actual usage of this chip - how much advantage do you think you're getting out of the IS on the manual lenses?

John

[acme]

Seeing the comments on the legendary Zeiss 85/1.4 I just can't resist mentioning the even more legendary Zuiko 85/1.4 GRIN. A lens so exotic that it employed a uniquely large "Gradient Refractive INdex" component, to correct spherochromatism without aspherical surfaces or multiple elements. It's believed roughly 50 were produced. You can read the relevant patent on google.

Here's a diagram of its design, hotlinked from the Italian site describing the lens. Full specifications are included in the soon to expire patent, in case someone knows how to make large slugs of GRIN glass and wants to build more!

[jebir]

That has to be tested before I can say anything.
As the effectiveness of the IS is depending on the camera-subject distance as well, I expect that there will be an optimum distance now that there is no communication between body and lens.
Also, as with IS in general, it seems like one gain less if the hand holding ability is very good in the first place.

I may come back with a post when I have figured ot a relevant test procedure.

Cheers, Jens

[acme]

As the effectiveness of the IS is depending on the camera-subject distance as well, I expect that there will be an optimum distance now that there is no communication between body and lens.

Is this stated anywhere? I've seen compensation described for pitch and yaw, but not for vertical and horizontal displacement. Anyway, until one got within a magnification of 1:50 or so, compensation for these would not have a noticeable effect.

[jebir]

I have weak memory that I read somewhere that Olympus mentions that the camera uses the distance information. However, I can't remember where. Olympus mentioned in the "Passion" series of articles that they were surprised by the complexity of the human handholding shake pattern so I hope that they used all available data to make as good a system as possible.

In any case, I'm planning to do some tests to investigate this.

Cheers, Jens.

[jebir]

Hi Acme,

this is an interesting lens indeed. I wonder if anyone have ever made any test shots on a digital camera with it? It should be interesting to see how it fares against the Zeiss 85/1.4 which Zeiss themselves claims to be the best resolving SLR lens ever produced.

Cheers, Jens.

[acme]

Hi Acme,

this is an interesting lens indeed. I wonder if anyone have ever made any test shots on a digital camera with it? It should be interesting to see how it fares against the Zeiss 85/1.4 which Zeiss themselves claims to be the best resolving SLR lens ever produced.

Cheers, Jens.

Well, I threw it in on a lark, as much to suggest that Olympus was once somehow more of a "fun" company than they seem to be now as to contribute anything useful to the thread. The lens appears to have been built to experiment with a new technology as much as to be a great design in itself. Given the effort and expense that went into its creation, I expect it's good, but how good we may never know since so few were produced.

[jebir]

UPDATE 2:

Now that I have been playing with the Dandelion chip also on my (brand new) E-3, I can say that the delay of the focus confirmation diode makes it very difficult to achieve precise focus. With the larger and brighter viewfinder of the E-3, it is actually easier to focus on the focusing screen than relying on the focus confirmation diode.

Cheers, Jens.