Dandelion x2 [50mm] experience

Started Dec 13, 2007 | Discussions
Jonas B Forum Pro • Posts: 14,596
Dandelion x2 [50mm] experience

This is a post about experience from using the Dandelion chip. It is divided in parts. Now it is three weeks ago I posted part 1 the first time. There wasn't much interest in it, maybe because it was posted in another heated 150-post thread about Olympus' not enabling IS with legacy lenses...

I repost it here, Part 1.

Part 2 is about my Dandelion No 2 (!!). It is a customized Dandelion and it arrived a few days ago.

But first a link: when I was about to post this I noticed Goffen had posted about his Dandelion that finally arrived. It is for tele lenses and his thread is here:
http://forums.dpreview.com/forums/read.asp?forum=1022&message=26002579

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Jonas

OP Jonas B Forum Pro • Posts: 14,596
Part 1 (144kB)

A repost from November 23, copied from here:
http://forums.dpreview.com/forums/read.asp?forum=1022&message=25729414

======================================================================

I received my Dandelion chip yesterday. I now have had the time to open the envelope and fiddle with the installation.

The Dandelion is delivered as a little printed circuit board (from now just called "chip") and you have to attach it to an adapter yourself. Instructions and glue are included with the chip.

The glue is not good. It is of the "one second from disaster super glue" type. The chip is supposed to be positioned with some care and you have better buy your own glue, for example a medium fast hardening epoxy type of glue.

The instructions are OK if you also do some thinking of your own at the same time. In pert 2 there are a few pictures of the chip and a sample of epoxy reinforcement.

======

Focus confirmation:

The FC works a bit so-so in my opinion. That is, it works just as well as it does with the Pentax cameras (experience from legacy lenses and the *ist DS and the K10D) or with Canon (experience from the 5D and chipped adapters) meaning you sometimes nails focus, sometimes not. The idea is to turn the focusing ring until the green light lits. In reality you can get green light and still turn the focusing ring quite a bit without loosing the green light. The is not of much interest to me; I bought the Dandelion for exposure experiments and for the IS. Anyway; try it for youself: it is pretty much the same as using a ZD lens with the camera set to manual focusing. If that works for you the Dandelion will probably work as well. I emphasize the word probably; different lenses are different. The AF function need some contrast and if your legacy lens is less contrasty the green light will be less distinct.
=======

Exposure:

I had some hopes for the dandelion to fix the exposure problem we have using legacy lenses. With the Dandelion you can set the aperture. Well, really, you can't do that, but I was under the impression that you could set any aperture value you wished for having the camera set to AE-aperture priority mode. With some experimenting that would have some impact onthe exposure readings when using a fast lens.
Lol - I was wrong.

It is all the same as before:

Why did I set the camera to f/3.7? The lens I want to use is the Summilux 50/1.4 and the aperture value should be set to f/1.4, or?

The problem here is that the set aperture value is not the same as telling the camera what the lens max aperture value is. The chip emulates a ZD 40-150mm f/3.5-4.5 lens. I have my camera set to step half EV stops for every click of the thumb-wheel. Maybe that is why I couldn't set the aperture value to 3.5, but to f/3.7 as the largest opening.

So, in practise I now have a state of the art digital camera thinking the lens is a f/3.5 lens, the aperture ring set to 1.4 and the exposure time calculated by the camera to an aperture value of 3.7... What a mess. But, it is not a worse mess than it was before the dandelion.

Oh well, let's see if the dandelion makers can make a chip for a 50/1.4 lens some day... or if we get another solution.

=======

IS:

IS works. That's all to say about it. Here is a free hand picture from the first series of pictures I took with the Dandelion:

Above: E-510 with a Leica Summilux-R 50/1.4, @ f/1.4 and 0.67 seconds. It's not pin sharp but it is certainly good enough for me, my shaky hands and the long exposure time.

=======

Overall:

The Dandelion is OK for now. I want an adapter that can be set to different focal lengths and it should also be capable of telling the camera what the maximum aperture is. And it should fit the Leica-R lenses... Hmm...

=======

?

Should Dandelion be spelled with a D or a d? It's a flower but now also a trade mark I guess, if not a registered one. I think I'll write Dandelion from now.

regards,

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Jonas

======================================================================
End Part 1

OP Jonas B Forum Pro • Posts: 14,596
Part 2 (650kb)

Part 2:

A 50/1.4 Dandelion

Continuation from Part 1:

I got the idea that the exposure maybe could improve, or even get correct!, using a Dandelion telling the camera the max aperture opening is f/1.4. So, I ordered a custom Dandelion for 50mm and max aperture 1.4.

Preparations
============

It arrived after a week approx and I got it earlier this week. Once again I started the glueing process, using an other adapter this time. Here are a few pictures from the adapter with the dandelion glued to it.

First we can see the adapter with the Dandelion chip. Here it is glued for the test run only and I have used the 5 second super glue that came with the chip:

and:

and:

and with the lens mounted:

Above: not much space between lens and chip

In the next picture we can see the chip secured with the better epoxy glue I mentioned in Part 1. As the Summilux_R 50/1.4 goes pretty close to the chip when focusing at infinty I took some care when applying the epoxy. I made sure it shoulldn't interfer with the protruding protective flange. The epoxy is possible to grind down. That's good but I prefer not having to:

Exposure:
=========

The interesting thing with the second Dandelion is the exposure reading. I had prettu high hopes for this. Alas:

Above: The 50/1.4 Dandelion, an E-510 and a Leica Summicron-R 50/2

The camera meters the light better with the 50/1.4 Dandelion and the 50Cron than it does with the standard Dandelion and the same lens. But... it doesn't meter significantly better tahn with without the Dandelion. The net result is that by setting the EV to -0.5 we get focus confirmation, IS and reasonably correct exposure from f/2 to f/5.6.

What about the Summilux?

Above: The 50/1.4 Dandelion, an E-510 and a Leica Summilux 50/1.4 E55

The result is pretty much the same as for the 50Cron. There is half a stop between the white lines in the chart and we can see that there still is a need for -1 EV compensation when using the lens wide open.

Oh well, there wasn't much in that brilliant idea of mine then. Right now I don't even want think about why it doesn't work. In the end I have got IS and EXIF values identifying the lens. Not too shabby but I really hoped the exposure meter should work better now.

Finally, a sample just for fun:

The above is after the raw conversion.
Here is what it looked like after having taken it:

There was a lot of light availabale, no IS needed... but it's fun to have the EXIF value identifying the lens correctly.

regards,

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Jonas

OP Jonas B Forum Pro • Posts: 14,596
Update 1 (154kB)

Due to the overwhelming interest in this topic i feel I have to post this update... :))

The custom 50/1.4 Dandelion screws the Live View function. LV works like one time out of three or so. Sometimes it just shuts down. I think this has been described earlier as a problem with the first generation of Dandelion chips. This was USD 40 wasted, or nearly so.

A sample, for the fun of it:

E-510, Leica Summilux-R 50/1.4 E55

regards,

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Jonas

OM4ever Regular Member • Posts: 470
Great Report,

Thanks.
Its a very tempting low light option, I think.
Jan

VGR Regular Member • Posts: 157
Re: Update 1 (154kB)

Jonas B

Thanks for the test! You have done good work!

duartix Veteran Member • Posts: 3,590
Re: Part 2 (650kb)

Thanks Jonas, your posts on this subject have been very informative.
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OP Jonas B Forum Pro • Posts: 14,596
Update 2, text only

Thank you for the comments guys. It's good to know somebody got something out of this.

As the second Dandelion doesn't deliver I have mailed and asked for a replacement where LV works and it is possible to dial in the aperture value used when taking the picture (but reading the light wide open, always). I'll get back here when I know how things turn out.

regards,

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Jonas

TrapperJohn Forum Pro • Posts: 16,488
Comment, and a dumb question

First off, thanks for passing on your experience. I'm watching this closely, as I have several legacy Nikkors I'd love to have IS with.

Now, the dumb question - what is the aperture value on the dandelion for? Is it to enable some of the auto modes? I run my Nikkors in full manual mode, using the light meter as a general guideline - the Nikkors, especially the 400 3.5, tend to like a bit of underexposure.

OP Jonas B Forum Pro • Posts: 14,596
Re: Comment, and a dumb question

TrapperJohn wrote:

Now, the dumb question - what is the aperture value on the dandelion
for? Is it to enable some of the auto modes? I run my Nikkors in full
manual mode, using the light meter as a general guideline - the
Nikkors, especially the 400 3.5, tend to like a bit of underexposure.

Thank you - encouraging comments guarantees the odd things to continue.

I can only guess what the aperture values involved makes for.

First it is a part of the whole emulating a ZD lens which the Dandelion provides, making sure the camera understand there is a lens mounted and that IS and FC should be enabled.

Then, and this is kinda extra, the aperture value should have an impact on the light metering. In theory; if the camera knows how fast the lens is and what the working aperture is supposed to be, then it can calculate the correct exposure time. Now these values are either a bit off or not present at all. That way the camera will overexposure with fast lenses, exposure normally with aperture values between 2.8 and 4 or maybe 5.6 or so and then again overexposure. This is with the E-510, fast 50mm lenses and in my experience only. YMMV.

regards,

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Jonas

OM4ever Regular Member • Posts: 470
Sounds right.

Imagine a 85mm f1.4 Nikkor w. Dandelion on the E3.
WOW
Jan

olyflyer
olyflyer Forum Pro • Posts: 26,680
Re: Sounds right.

OM4ever wrote:

Imagine a 85mm f1.4 Nikkor w. Dandelion on the E3.
WOW
Jan

I think, you'd only confuse the E-3 metering. Unless you really, really desperately need the IS, the E-3 supposed to have so large and bright VF that you don't need the focus assist function to focus.

Of course, I can be all wrong, but I don't think so.
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olyflyer
olyflyer Forum Pro • Posts: 26,680
Re: Sounds right.

olyflyer wrote:

OM4ever wrote:

Imagine a 85mm f1.4 Nikkor w. Dandelion on the E3.
WOW
Jan

I think, you'd only confuse the E-3 metering. Unless you really,
really desperately need the IS, the E-3 supposed to have so large and
bright VF that you don't need the focus assist function to focus.

Of course, I can be all wrong, but I don't think so.

I think I have to take this back. I read in another thread that the Dandelion 2 sets min lens aperture = max lens aperture, disabling selection (dialing in) of aperture in the camera. If that is the case, and you get one made for 85mm f/1.4 it will probably work. However, fast lenses (faster than f/2.0) are still a problem for some of the cameras, maybe not the E-3. Regardless of which, that is not caused by the Dandelion.

The reason why if max = min is not causing an exposure problem at any aperture is that the camera then assumes any aperture being the most open one and calculates the shutter speed from the available light. The camera is just a stupid box, it has no idea about which aperture you actually selected on the lens since there is no feedback at all to the camera, other than what the Dandelion delivers.

I am not saying the Dandelion would work for you, I don't have one, but to me, after some more reading, thinking and experimenting, it seems reasonable to believe it would work. It's just a pitty the makers of Dandelion can not explain how and why it is working, if it is working. But, if the E-3 view finder is really as bright and large as I have heard it is, than maybe there is no reason to get the Dandelion, unless you really need both the FC and the IS.
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Hokuto
Hokuto Veteran Member • Posts: 4,908
Thanks, Jonas

Glad you posted this.

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OM4ever Regular Member • Posts: 470
Sorry,

I was, but didn't say, excited by the lowlight possibilities of a fast, eqvlnt.
170mm stabilzed lens on the E3.

I would expect an error factor with metering, and would not rely on
FC. Considering all the manual camera work in my past, those
conditions are not really an issue.

For me, the Dandelion is about IS.

Thanks for the thoughtful answer.

Jan

OP Jonas B Forum Pro • Posts: 14,596
Re: Sounds right.

olyflyer wrote:

-snip-
The reason why if max = min is not causing an exposure problem at any
aperture is that the camera then assumes any aperture being the
most open one and calculates the shutter speed from the available
light.

As showed here in this thread it doesn't work. I don't know why really. Maybe it is something with the viewfinder screen not getting brighter in a linear fashion at wide apertures? Why it is that way is beyond me but it has been showed to be that way by other members here earlier (now thinking of measurements somebody did with the E-1). It would be interesting to see what the exposure is like with cameras using the AF sensors for spot metering and thus should be unaffected by the viewfinder screen.

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Jonas

OP Jonas B Forum Pro • Posts: 14,596
Update 3 (text only, short)

In the last update I mentioned I contacted the Dandelion people describing my problems.

I got a very friendly reply where they told me they didn't know about the IS problem and that the v2 style where min aperture = max aperture is made that way to prevent people from switching the value by mistake. We agreed that I'll send them the custom Dandelion back for examination and replacement.

As we have the Christmas and New Year holidays in front of us all this will take time.

Hokuto: Thank you for your nice comment. Heh!, you just ensured the continuation of this thread with further updates. Let's say that will happen in a month or so.

regards,

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Jonas

OP Jonas B Forum Pro • Posts: 14,596
Update 4: Dandelion, now v3 (202kB)

(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.

Question:
-------------

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.

regards,

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Jonas

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