Iscorama pre 36 help / questions

[BenCoughlan]

Hi Guys

 

So Im new here, Thought I would put out a few questions out there to help me get to grips with the isco.

 

I recently bought a pre 36 Iscorama. It was paired with a Nikon taking lens. I have just started playing around with it. I have a restan clamp and at the moment, most of my test have had it paired with a Zeiss Contax 50mm 1.4.

 

My first and main question is about the image. I find it quite hard to focus. Nothing feels pin sharp. At first it kind of remended me of using a redrock 35mm adapter on my z1 (going back many years). Obviously it not quite as bad as that, but it is hard to tell focus. Is this just how these lenses are? or do I need to go and get mine serviced?

 

At the moment its strapped on to the front of my c300. I Have strapped it on to a BMCC too (2.5k) but havnt done anything extensive on that yet... Again tho, nothing felt pin sharp. Its obviously a bit better as I close the taking lens down towards 5.6 but I like to shoot stuff fairly wide open.

 

I have a bit of a work around at the moment.... What I have done is throw some zacuto bars on the bottom that I had lying around, then mounted my TV logic just above the taking lens. I can then un squeeze the image from the c300 for monitoring... I have then mounted the c300 screen the wong way round (I lost the top handle as it just adds extra weight and height) then when you flip it out you can have it off centered to the right instead of the left.. Next I clipped a zacuto z finder on to the c300 screen. I dont ever actually use this screen for monitoring or operating. The sole purpose is to check focus, so I leave the cameras peaking on, as well as the magnify option. what I do is stick my eye into the z fider to check my sharps, then operate using the TV logic. This works great when shooting from the hip. The camera is nice and compact. I can then flip the c300 screen the other way and do a similar process for shoulder mounting.

 

I have attached some snaps so you can see what I mean. (excuse the iphone quality)

 

Really the question is, should my Iscorama be this difficult to operate... if I was just using the TV logic I would constanty be questioning if it was sharp. Close focus is much easier, as everything else falls off. The real problem is from aroung 8-12 feet. When I am at infiniti I dont question it so much as I can just go on the distance.

 

Any help would be much appreciated.

 

some test footage. (nothing special)

 

https://vimeo.com/73722976

[Tito Ferradans]

Ben, if nothing feels in focus, then there's something wrong. Try other taking lenses. If it still feels bad, you should get it serviced. I can get tack sharp focus with any lens I've tried so far, even wide open. :)

 

Oh, the camera I use is a 5D3, so it's not sharp because it's on a smaller sensor. hehehe

[Rcorrell]

Taking lens.  or at least sounds like it.  The taking lens needs to be set to infinity (or near it depending on on lens ) and remain there, and focus only with the Isco.  If you do have the original nikkor lens that came paired with the pre 36, it is a good way to test if in fact your problem is with the Isco attachment or not.  The original taking lens, is premaritally fixed to infinity in order to work with the Isco lens attachment, in other words, it does not have the ability to focus.  So a good way to check is get a nikon adaptor for, canon EOS it seems like, and try that..  that should be tack sharp at f2.8 throughout the focus throw.. if that doesn't work then it is your attachment lens that is the problem.

[BenCoughlan]

Thanks for the reply guys. I am going to do some more extensive tests this Sunday. The taking lens is always set to infiniti. I will try it on a range of different lenses. Old and new. I have a takumar 50mm 1.4 and a helios 44-2, and a range of newer canon primes.

 

One final question. Should the Iscorama image look as sharp as the image if it were just the prime taking lens. My thinking is that its going through quite a lot of extra glass and that might soften it a sniff. I will upload a load of with and without still frames from the test.

[dahlfors]

Just watched your video and I agree. Looks like the taking lens you used was a tiny bit off focus. The Iscoramas produce far sharper images.