Dandelion x2 [50mm] experience

Started Dec 13, 2007 | Discussions thread
Jonas B
Forum ProPosts: 14,596
Update 4: Dandelion, now v3 (202kB)
In reply to Jonas B, Feb 20, 2008

(Sidenote: There was another update before this one. It probably got lost during the DPR server crash some time back. In that update I showed the results from the new customized Dandelion v2 I had got back then. As v3 of the chip is out and working there is no need to repost it.)

Dandelion, from the Olyslrclub guys, version 3 - programmable

I have now had two pcs of the new v3 of the Dandelion chip for a day.

First impression:

I ordered two Fotodiox adapters, ready for use with the new v3 Dandelion glued at place. Ordering, communication, paying, shipping/getting them - all was fine.

When opening the Fotodiox boxes I got a bit disappointed; in one of them the chip had got loose during the transportation. Looking at it it seemed to have been glued to the adapter using very little glue. I then opened the second box and there it was OK. As I'm a suspicious sort of human I tapped on the chip with my finger. Ooops, the chip jumped away and landed on my kitchen table. That was good and bad.... I very much prefer having the cip on the table than on the lose inside the mirror chamber.

The bad thing is of course that I had to glue them back myself. Now it didn't take much more than 10 minutes. I'm getting good and fast at this now... As described earlier I added extra epoxy to the back side of the chips making them secured to the adapter to my taste. This is what it should look like:

Using the super fast super glue only is not safe (as mentioned already in the Part 1 post).

In use:

Programming focal length and max aperture opening is easy.

When in use the aperture value reported in EXIF can be changed by using the thumb wheel. That's nice as at least I sometimes want to know what aperture was used. If it is not recorded in EXIF it is not remembered.

IS works fine, bot when taking the picture and when framing/focusing using Live View.

Focus confirmation works. I have an E-510 and the confirmation signal is a bit slow. I don't know if it is the same with other camera models.

Exposure reading:

I posted the same chart in the lost update. Now it is here "again", showing the exposure result when using a 50/1.4 lens without any Dandelion, and with the different Dandelion versions.

If you care about stuff like this:

Blue line: The exposure result when using a fast 4/3 equivalent lens

Red line: The exposure result when a 50/1.4 lens is used, no Dandelion at all

Yellow line: Dandelion v1. As I recall it now the v1 Dandelion reported a max aperture value of f/3.5 or something like that to the camera

Light blue line: Dandelion v3 set to report f/1.4 as max aperture

This far we have seen the exposure result having the camera set to "A" (automatic exposure with aperture priority)

Now we can look at the curves when using what I call "Alt mode" in the chart. The Alt mode means I read the light with the lens wide open, lock the exposure and then turn both the aperture ring and the thumbwheel to the aperture value shown in the chart. This is pretty much the same as helping the camera acting as if the lens really was a native 4/3 system lens:

Black dotted line: The customized v2 Dandelion. It worked a bit so-so. There is a glitch at f/2.8 which one had to remember. For some reason the pictures also were overexposed with the lens wide open. I never understood these two glitches and in the end I didn't like to work this way.

Black line with small gaps in it: Dandelion v3, Alt mode. Wohoo! Now we suddenly get correct exposure with the lens used wide open. And also at f/2. Then we run into problems again at f/2.8, just as with the v2 of the chip. f/4 is OK, another problem occurs at f/5.6 with more than a full stop of under exposure. The results from f/8 and up are all good (but of little interest).

Why use a Dandelion?

Now that Olympus have done what they should have done from the start this question is a good question.

To me it is about the luxury of being able to switch lens without thinking of the FL. There is no need to dial in the correct FL as the chip takes care of this. And the FL is exact. I don't know if this matters in the long run but it feels OK to have the FL set to the lens FL, exactly (or as exactly as it gets as we focus). In the long run this feature only makes the chip worth the money.

It also about the exposure meter. I can finally trust the exposure meter at f/1.4 and f/2. The glitch at f/2,8 is annoying though; I have to remember to dial in EV compensation (-0.5 or -0.7 EV) here.

Having the EXIF values correctly reported is a bonus.

Expensive? I don't know... The Fotodiox adapters are good. Adding the chip isn't that much extra. And if you have good lenses they all should have their own adapter anyway. Nah, I don't think it is expensive.


What about the glitches at f/2.8 and f/5.6? I tried with two different chips, two different lenses. The result is the same. So, if it is not the aperture, then it is the shutter. The expected shutter time is reported in EXIF. For now I think the chip affects the camera somehow and the shutter time is not correct. Strange?!

I guess one can find out about this by taking pictures of something moving with constant speed (perhaps at longer exposure times) and by measuring the length the moving subject moved one can calculate the relative shutter speeds. (I'm sorry for that sentence.)

I'm not intended to find this out. For now I'm rather planning on selling my Olympus stuff. I also guess not many cares about this my Alt mode.

That's it. I hope it helps someone.


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