Given that you are using the cropped sensor Canon 600D I would suggest a focal length of between 135mm and 160mm would be about right to get maximum center sharpness without loosing too much in the corners. That is about 3.5 to 4x. A lens will give the crispest pictures when used at an optimal magn...

I'm, so happy we've reached a kind of agreement, and that I have learned something in the process. By the way, is there any way to tell if a microfilm lens or other small lenses of that kind, like the famous JML or the 20mm Otamat, are infinite, and in that case, which fl tube lens is required, or f...

Thanks a lot guys!
Then I have to return to my former statement/question: "Isn't it (the 5x0.14) more like f/3" and conclude: Yes it is - in combination with a 200mm tube lens, which is the way it is used anyway

Aperture= 1/(NAx2) 1/(0.14*2)= 3.57. So an aperture of about f/3.57. That is an approximation but, if I have it right, close enough for low NA's. Oddly, that formula appears to be an approximation but it's actually exact. The reason is explained in the second half of the posting HERE . Regarding je...

Ok, ok, I get your point

Yes, I can see that, but I suppose this contraption is aimed at high mag shooting and then f/11 is way into diffraction land anyway, so why use it?

Sorry, maybe I'm missing the point completely here! When I am shooting my reversed enlarger lens placed on my OM Telescopic Tube, I am using the aperture in this lens as it is the only one! Ok, I can see that if you use a very small aperture, you would loose some light, but then again, for high mag ...

Thanks! I wasn't aware that the correction factor only applies for finite objectives :oops: By the way, I did some test shots after the reassembly of the Mitu, comparing it with the Nikon CFI60 10x/0.25 on a 100mm OM lens, and the Mitu images were softer, but I guess they have to be, effective f con...

Now, here's a pic showing the disassembled unit with the 4 groups of lenses layed out in the correct order. Left to right: bottom to top. http://www.photomacrography.net/forum/userpix/3293_Pikkemand2_2.jpg As far as I can tell, there are no problems putting the things back together, but a more thoro...

I believe it is an older version. The fact that the lettering is engraved and filled with lacquer seems very old school (and nice) as opposed to merely printing the writing on the barrel. Furthermore there are no official pictures of it in any catalogue I have seen.

And isn't it more like f/3?

Funny enough, there is one for sale on ebay:

http://www.ebay.co.uk/itm/Mitutoyo-M-Pl ... 2ece694b05

Yes, I saw this. I must admit, that I find it hard to believe that a slight rotation of a lens group can disturb the funcionality at all. I mean, how on earth would you fixate the groups when you tighten the final lockring? They have probably constructed it this way to make the final assembly easier...

Well, it doesn't seem to a big deal. The lens elements are all cemented in 4 different keepers, so you just have to get the order and the direction right.
Anyway, I got the whole thing together again, no problem at all.

The diameter of the front element is 14 mm and the working distance is ca. 34 mm. When I was measuring this I mounted it on the camera in order to measure the working distance without the front ring, which resulted in the whole thing coming apart :shock: It turns out that there are 4 individual grou...

Here comes another update on an old post! When suddenly the price on this objective got lowered to a little more than 200 $ I couldn't resist it any more. I bought it. Here is a shot showing the funny hood-like front thing: http://www.photomacrography.net/forum/userpix/3293_P2220016_1.jpg And unscre...