Here, "sort of" native m4/3 75mm F1.8 lens

I missed this thread, and I'm glad that it worked out with the spacer rings! Congratulaitons on the success of the experiment.

I just received a 45/1.8 for Christmas, so I'll be trying this combination out soon.

The TCON-17 is a superb-quality optic, and I've used it on various primes and even zooms, like the 45-200.

Of course, all this comes just as it sounds like Olympus will be releasing a 70/1.8 lens!

micksh6 said:

Lights said:

I think there is the TC0N-14 for the Oly E-10/20 it's only 1.4 and the Oly TCON -300s also for the E10/20

http://www.cs.mtu.edu/~shene/DigiCam/User-Guide/FZ-30/Converters/TCON-300/TCON-300.html

The 300 seems pretty unusual...it's 3x plus it has rudimentary focusing on body I think..then your autofocus is supposed to take over. I've never seen one in person.

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I think it's TCON-14B that is for E-10/20. TCON-14 is for P&S.

And I was surprised to find out that E-10/20 have 2/3" sensor. So, I would not hope that TCON-14B has much better coverage for m4/3. And it weights more than a pound.

As for TCON-300 - well, I don't know what to say. Looks interesting, for academic reasons perhaps.

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could you post a shot at f1.8 with a full body shot so that we can see how it will blur a background in a full body portrait..?

micksh6 said:

I call it 75mm despite 45*1.7= 76.5 because with 4 rings between lens and adapters field of view is marginally wider than with single ring. 4 rings are needed to increase circle of sharpness, though.

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Why are the 4 rings needed? Whats the science behind it? Why 4?
And what rings did you use?

Thanks!
--
Rick Halle wrote:

" Keep in mind that tall buildings sway back and forth so they require faster shutter speeds."

AV Janus said:

micksh6 said:

I call it 75mm despite 45*1.7= 76.5 because with 4 rings between lens and adapters field of view is marginally wider than with single ring. 4 rings are needed to increase circle of sharpness, though.

Click to expand...

Why are the 4 rings needed? Whats the science behind it? Why 4?
And what rings did you use?

Click to expand...

In the post with samples I provided a link to the "try more spacers" suggestion http://forums.dpreview.com/forums/read.asp?forum=1041&message=39832089

I don't know the science behind it, this is an empirical knowledge to me. I used all rings that I have between 37 and 55mm - 37-46, 46-49, 49-52, 52-55mm. I may try inserting polarizer in between to see what happens (I don't have clear UV filter).

I will post full body samples on the weekend and will post-process head portraits in this thread, they are severely underexposed. But you can see DOF is very thin.

And for full body shots I will have to make sure that head is not close to frame edge. This combo is still rather soft at edges, although it's better than without extra rings.

What size lens does the TCON17 normally fit? Is it filter thread or bayonet?

Thanks! I'm interested...

The TCON-17 is a 55mm filter thread front-mounted teleconverter. It was designed for the Olympus high-end 35mm superzoom cameras, so image quality is very good when it matches a prime lens well. Typically, a small amount of CA and some flare are introduced. I used it on my 45-200 to extend the reach, but more so, to extend the range where I would have a wide aperture (essentially a 0.7-stop improvement). Possibly the same could be done with the 100-300 zoom.

Regarding the question about spacers, this is based on empirical knowledge - these front-mounted teleconverters are designed for a specific lens and a specific distance from the front element of that lens. I suppose it is related to the size and curvature of the front element and many other factors, but calculation is prohibitive.

Since here we are using them on a lens it was not designed for, the usual approach is to vary the spacing to optimize the sharpness across the field. For some lens/converter combinations, this is possible, for others, it never reaches an acceptable sharpness through the field of view. You can see examples of this varied lens-to-teleconverter distance if you look at Raynox's web page and the various distance adapters they have for mating converters with various camera lenses.

don_van_vliet said:

What size lens does the TCON17 normally fit? Is it filter thread or bayonet?

Thanks! I'm interested...

Click to expand...

robertro said:

The TCON-17 is a 55mm filter thread front-mounted teleconverter. It was designed for the Olympus high-end 35mm superzoom cameras, so image quality is very good when it matches a prime lens well.

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This particular converter was an accessory for some compact cameras with small sensor. So you are saying it existed for 35mm cameras and they just re-released it for digital compacts? Then there is probably a chance to make edges sharper by experimenting with spacers.

There are also different revisions of this converter (also for compact cameras) - TCON-17C and TCON-17F. AFAIK these have proprietary bayonet mount instead of filter thread.

Now I know why Olympus chose to make 75mm F1.8 prime. After seeing my post they wanted to prove that they can design new lens better than I can assemble lens from existing pieces. Well, we'll see about that.

BTW, the "plunger" as it was called in another thread, doesn't have to be always on the converter. But I wish it was a bit smaller. Panasonic's upcoming 2x DMW-GTC1 is 3 times lighter and way smaller. Interesting to see if it will work on Oly 45mm.

compositor20 said:

could you post a shot at f1.8 with a full body shot so that we can see how it will blur a background in a full body portrait..?

Click to expand...

compositor20 said:

could you post a shot at f1.8 with a full body shot so that we can see how it will blur a background in a full body portrait..?

Click to expand...

I shot some skateboarding today, here is one photo that I will keep, made with 45mm plus TCON-17. I got more decent photos, I used both bare 45mm and 45mm with converter (plus polarizer, to keep lens wide open under bright sun). Will select and process tomorrow.

And two quick snaps just to show background blur as requested. With converter and without.

You can see 75mm blurs background much more than 45mm with subject being approximately the same size. It seems to me that TCON converter actually adds some 3D effect.
I will post more samples later.

This combo may look like a joke but it does not perform like a joke. It performs like a real lens, I think. This can be an approximation of what upcoming Oly 75mm F1.8 lens will be (if rumors are true). Meanwhile I'm going to use this combo more.

Thanks for starting a really interesting thread.

And the bonus was the para below. Judging from the photo of your kit, I reckon you've laid down a challenge that Olympus will struggle to step up to - certainly in terms of kit that will turn heads!

micksh6 said:

Now I know why Olympus chose to make 75mm F1.8 prime. After seeing my post they wanted to prove that they can design new lens better than I can assemble lens from existing pieces. Well, we'll see about that.

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--
Paul

Those look very good. I've been very impressed with the TCONs that I've got. Very little or no light loss...and surprisingly good in the corners for what they are. I've got the TCON 0.8B (which I use on my Canon's lenses + on my EPL1 when I get the step ring soon) The TCON 0.8D for my COly 8080, and the TCON 0.7 which I use on a C5050 (24mm at F1.8!) and have on my EPL1 with some vignette apparent on my 14-42, since I have 2 step rings together... and it puts the lens too far out, I've found a place to get a 40.5 to 55mm in a single ring, so will be ordering that. The only problem I've had is flair (since the front elements are quite wide), and mounted on certain other lenses..some CA. The 0.7 has more distortion than the 0.8's but is easily corrected with software. Those last pics seemed very sharp and colors look good too. Very interesting lens.
--
http://www.pbase.com/madlights
http://barriolson.aminus3.com/



Like the Joker said: Why so serious?

Thanks. I posted more samples in separate thread. Oly 45mm with and without converter, and also Canon FD 135mm F2.5
http://forums.dpreview.com/forums/read.asp?forum=1041&message=40518854

Thanks for the comparison even though they are not at the same distance... i can now say that i wont buy the 45mm f1,8... its a shaem that 75.18 wuld be expenseive... i have a canon fd 50mm f1.4 but its nly usable at f2...

m43 has enough backgrund blur for halfbody shots ... but the full body are troublesome.. now it seems it isn´t anymore