richg101

IMO the drawbacks of the offerings in the full frame dept are too high.  when someone makes a 4k full frame sensor, this will be the key.  even the 1DC doesnt use full frame on any of its proper recording modes.  4k is cropped to aps-h which is not full frame, or anywhere close.

 

If the vg900 had proper profiles like on the nex 5n and nex 7 id have been on it.  you cant get flat profiles on the vg900.   moire on the sonys is overtalked based on rubbish tests.  Set your sharpening to -3 (if you can and I bet its fine).  A99 has stupid mount meaning you need to use sony a mount lenses which will no doubt be fazed out in a matter of years - why use lenses which need a 50mm+ flange focal distance when mirrorless is the way forward.  Add to that, Sony A mount are consumer, and have a limited following so they will be worth nothing in a matter of years, and I'd never think of buying expensive consumer lenses from Sony. 

the c300 (or c500 if you need 4k) is not lacking features, but instead lacking gimmics.  all anyone really needs is 24p or 25p.  I'll admit, It would be nice if they did 50p full hd.  but the 50mbs 4:2;2 into card, with c-log in that form factor is my idea of bliss.  c300 is not much sharper than the hacked gh2 from what I have seen, but it has a proper sensor and amazingly clean high iso's meaning lighting is easier and cheaper.

 

c500 is too expensive.  but i think the c300 is bang on the money.  lovely little machine

Why is this?

 

 

The form factor and form factor alone.  

I cant see a situation where myself or 99% of the readers here would ever come into a situation where the performance of the c500 (or the c300 for that matter) isnt enough.   

i'd still choose the c500 over the rest.  

I am very confused here because the statements being made are conflicting with my own personal experiences using a century 16:9 adaptor (pd150) and a tokina +0.4 achromatic diopter.  When using the combo on an aps-c sensor and 28mm taking lens, I was getting way better sharpness and less CA over the entire focus range (which was around 500mm-infinity).  The benefits were not just in improving close focus.

 

Am I right in assuming that you (John) are saying that if I were to fit a +0.4 (non achromat) instead of the tokina +0.4 (achromat), I will still obtain the optical improvements in the more distant focus range?  

 

I had my century and tokina continually used together and never needed to separate them.  I got sharper infinity focus at f2.8 with the tokina achromat that without.  Are using saying a non achromat will have sharpened up my infinity focus and overall CA issues in the same way as the tokina?

 

 

Conversely, I do not get any noticeable sharpness improvements when I use a tokina achromatic diopter +0.4 on an iscorama 36.  All I gain is a shorter minimum focus distance.  Sharpness and CA on the more distant subjects which wouldnt need any closer focus ability is not affected by the tokina when used on the isco which introduces next to no noticeable CA and very little dulling of sharpness even when the taking lens is wide open.   

 

I honestly believe that in respect to the century and panasonic 16:9 converters there is a noticeable improvement over the entire focus range when using the tokina.  And I struggle to see how adding a non achromat (even of the highest quality) would go any way towards doing anythign other than applying magnification.   

need a wide angle?

 

http://www.ebay.co.uk/itm/Nikon-Nikkor-6mm-F-2-8-RARE-Lens-Ais-Alexa-Red-Leica-C300-PL-Arri-Cooke-Zeiss-/370706916376?pt=Camera_Lenses&hash=item564fdaa418

Thanks for the info to my question folks : ) I'm not sure I have the balls to do this mod [at the moment anyway] But I was wondering if there is any possibility of freeing up the 'tight' focusing action at the same time as doing this mod - or do you need to be a qualified lens tech to go any further into dissassembly?     

 

 

indeed you could try.  and I doubt it would be very hard either.  it would be a case of carefully unwinding the front element past the maximum - I accidentally did this while I was doing my modification.  if you twist the focus much more than a whole turn it comes right off.  

 

You will need a very careful hand to make sure you dont damage the very tight thread when unscrewing and putting it back together.

 

 

then I would look at carefully cleaning off the grease off the male thread (on the part that comes out (which holds the front element), - you'll have to research what type of de-greaser to use.  but dont use a spray application.  you would want to spray into a lint free cloth and just use the cloth on the thread.  a piece of an old 100% cotton t-shirt would be good.  then re apply with a similar type of grease and then re-assemble.  see if this helps.  if it is still tight you might have to do the same to the female thread which will be harder to get to.  I imagine the new grease on the male thread will work into the old dried up grease on the female part and after time will loosen up nicely.  

 

While you are in there doing the focus mod, you are only 1 step away from being able to get to the dried up grease/dirt build up which is causing the tight focus ring turning.  If you feel you can unscrew/rescrew it back toghether without dmaging the thread then go for it!  I managed.

Horse shit.

 

I bet you drive a Porsche 944 like me!

Muppet

The chain of events goes as follows:-

You respond to the topic suggesting achromatic diopters are not required with anything less than +1 magnification which was wrong in this instance.

I correct you and explain that the tokina +0.4 actually is beneficial being achromatic.

Upon your authority being questioned, you came up with another bold and ignorant suggestion that anamorphic with less squeeze than 2x is for 'cheapskates'. Then try and make a comparison between a choice of lens and a choice of automobile... baffling!

I correct you again, and inform you that your comments are ignorant.
ig·no·rant /ˈignərənt/ : Lacking knowledge, information, or awareness about something in particular

You suggest i am being insulting to you. Never expect to come onto a forum spurting ignorant and bold things without expecting to come away feeling insulted. I did not mean to insult you, but more to make others aware that your suggestions are made based on ignorant opinion and not real life experiences.

I dont believe I am in the wrong Forum unless you speak for Andrew.

 

Anamorphic Cinemascope is and always will be 2x including flares, stretched Bokeh, and 2:1 elliptical aperture reflection

 

Anything else is a small format cheapskate pretender to the real deal. Like a Porshe 944 hairdressers car :)

 

just sayin'

 

 

You're spurting ignorant things my friend.  I'm unable to shoot on an Alexa studio, and unable to shoot on 4perf 35mm film meaing for me, 2x is too much squeeze.  Most people here are in the same boat as me.  But we make do, and actually create things on our 'cheapskate pretender' rigs.  You on the other hand create nothing and instead just come here to stir up trouble with ignorant statements.  

 

As far as hairdressers cars are concerned, you're comparison is pretty dumb.  I'd rather a hairdressers car than no car at all.  

 

Go start a topic on the forums for real cinematographers and leave us cheapskate pretenders alone.  We are not worthy

The best way to improve the sharpness on those adapters is , IMO, is to remove them and simply crop the image.

You're in the wrong forum then. i think everyone here knows that cropping the image will yield sharper results. degradation of sharpness is a sacrifice everyone here is willing to make. even without the oval bokeh, the la7200 and century still provide the real flares and a organic look that cannot be replicated in software.

the tokina sharpens the century very well

no need to get snarky, just sayin

 

Nikon only went with achros on the higher dioptr range Ref http://www.mir.com.my/rb/photography/hardwares/classics/nikonf2/macro/index3a.htm

 

and Zeiss Proxars  for Hasselblad were all single element I believe

 

Nizo (Schneiders) were the same

 

Those diopters wont apply any improvement to the sharpness and CA on a century or la7200.  the tokina achromatic actually sharpens them overall.  even at near infinity, the tokina +0.4 improves the century when used on aps-c.

an external monitor is a nice thing to have.  messing around with a piddly little 3" screen is no fun when tracking focus on a moving subject.  An EVF or Loupe is also nice.  assists with focusing, but most importantly gives you a 3rd point of contact meaning you get more of a shoulder mounted, smooth look to your footage.  

if it still doesnt want to budge, use some lens cleaner fluid (high alcohol content) - like Calotherm / Caloclear spray.  If you apply enough so the cleaner can seep a little between the ring and the front element (by capillary action) it wont evaporate as quickly and as it pools between the two surpaces might help to break the friction grip between the glass and the rubber seal that sits between the glass and the plastic ring.  obviously you'll have to wait for it to evaporate from the ring so you can grip onto it.  The lens cleaner might offer a degree of lubrication too and wont leave residue once it evaporates.  

I thought not, but the ring IS tight.  I'll go buy the rubber gloves.  Thanks!

 

 

yes.  don't force it if it wont move without rubber gloves.  And once the ring has started to spin, make sure you dont apply too much pressure to it.  - it's not metal, the ring is plastic so might snap if you use excess force.  the rubber gloves mean you dont have to put as much pressure on the ring.

OK, now I get it.  Thanks for your help!  I'll try it soon.  Would the application of lubricant like WD-40 help, or would it potentially harm the optics?

 

 

NO!!  don't do it.  do it dry.  with rubber gloves if it is tight.  wd-40 is NOT for lenses:)  

Is this the known slacken the screws? mod

Does it show softer focus at F2?

If this method involves what I think it does, 'slackening the screws' will only allow you to change the focus range from original 'infinity to 6feet' and change it to a 'macro only'. when I say macro only, you will be able to adjust so the focus range is changed to the minimum of about 3.5ft to around 8-10ft maximum. the two stoppers on the inside of the plastic focus ring are the determining scale - they allow 1/2 a turn as standard. in order to get 3.5ft-infinity you need to be able to rotate the focus ring 1 whole turn from the point of infinity. - to allow this the 'minimum focus point stopper' needs to be grinded off the inside of the plastic focus ring.

I have an early [mint] plastic Iscorama that came with the Nikon mount 50mm f2.8 taking lens [which I believe is different from the 36] - does anyone know if this mod would be the same?

 

 

I am unsure.  I would suggest reading the wiki page to determine if the front 'anamorphot' part is the same as a typical '36'.  I doubt there is much change in construction on the actual anamorphot part - you are not affecting any part of the taking lens (which I believe is the only differece between yours and a normal 36.)

Removing the plastic ring is the part that worries me. Are we talking about the flat ring with the iscorama label printed on it only (recessed into the 72mm threaded lip)? Or do you grip the focus ring on the outside and unscrew it like the lid of a jar? (It seems to be one solid piece). I'm mostly concerned about applying too much pressure and breaking something.

The rest of the instructions seem straightforward.

Not the jar way - the focus ring part with the ribbing and printed focus scale is a solid part. you need to remove the the ring (with the "isco-gottingen iscorama anamorphot 1.5 - 36" printed on it) on the inside of the 72mm thread. as you twist it, it unthreads from the same thread as you would attach diopters. you cannot physically grasp the ring due to it being recessed into the thread so you need to press against it while trying to twist it at the same time - in the same direction you would untwist a diopter from the 72mm thread.

QuickHitRecord had to use some rubber gloves in order to allow him to spin the ring - otherwise there isnt enough friction. mine came away slowly by hand, but it would have been quicker if I had used some rubber gloves. Make sure you mask off the front element with some masking tape to be sure you dont scratch the element.

i dont want to take mine apart again. anyway I dont think images will help. you need to see inside first hand. it's very simple* once you get inside and the main optical elements dont need to be touched.

1. set the iscorama to infinity

2. remove the plastic ring around the front element with 'iscorama 36 - 1.5 etc' printed on it,

3. unscrew the 4x screws with the right size precision screwdriver. - store safely!

4. the plastic housing will lift off easily (the plastic part with the focus scale printed on it).

5. examine the inside of the plastic housing - you will see two stoppers - one of which needs to be shaved away with a dremel multi. you need to actually look at the inside to understand what is going on. it's simple once you see inside. one of the stoppers is for infinity and one is for minimum focus. it becomes apparent which is which once you are inside.


6. clean the plastic housing in cold water to remove the grinded plastic dust and then dry properly.

7. re assemble as before.

NOTE:- after the modification take care not to turn more than 1 whole turn or the front element will untwist completely. with mine I make sure not to turn the focus ring past the infinity mark.

*simplicity is subjective I suppose. if you are not used to handling precision screwdrivers, or using a dremel grinding tool to grind soft plastic, I don't suggest you try this.

I think of all the technical advances in the last 3 years, I would still choose film and panavision over anything else if I had a script worthy and there were no financial constraints.  I bet there are still the utmost of epic cinema productions such as these being shot on film in 5-10 years and beyond.  

Success!

I have completed Rich's "surgery". I am now able to focus at 3'2" without a diopter (any further and lens begins to wobble), wide open at f/1.8 and seemingly without a loss of sharpness:

GH2 with Nikkor 50m f/1.8 AI-S @ f/1.8 and newly-modded Iscorama -- this is how close I am able to get.

I did superglue in in my own jury-rigged limiter, but the throw of lens is so far now that it isn't making contact. I'll probably just put a red tape mark on the lens to indicate the closest that I dare to focus (though it's very obvious when you've gone too far).

Today is a good day. Thanks again, Rich, for having the guts to be the first to open up a $3000 lens and poke around.

maybe work out the minimum focus point you can get where your new stopper/limiter still works and set it for there? at 3.2' that front element is about 5mm further out so wont be near the contact tab it is meant to hit. I bet it is not massively far away though.

I think we need to figure out some sort of external stopper. or, modify the other section of plastic housing where the stopper contact tab is attached. so the new stopper/limiter can be brought further down slightly so it still makes contact with the tab. if we just put a stopper in a position where it still makes contact with the tab at 3.2' minimum focus the stopper wont allow the focus ring to wind all the way back and reach infinity, so the points where the stopper might fowl would need to be cut away. though, this will render the lens always having a sma gap so you can see the metal front element housing even when taken back to factory if that was ever required. I think I will do this because I dont see myself ever selling the iscorama now. and i feel the modification adds value to 90% of users. collectors might not be that keen, but mine was never a collectors piece before I got it, and gets used regularly.

I have been trying for an hour to remove the front "Isco Gottingen" ring. It's on there pretty good. I have washed my hands many times. I've tried latex gloves and rubber bands, but nothing is budging.

 

EDIT: Rubber-dipped gardening gloves did the trick on my first try.

hahahaha.  nice one.  I wouldnt have even thought of rubber dipped gloves.  based on my experience too, this it definitely the best option.  perfect 'shore rating' of rubber to grip onto that slippery ring.

 

 

 

for those worried, the process is quite nice because once you get the ring and the screws off, you can see straight away if the job is above your capabilities.  if so, just replace the screws and screw the ring back on.  setting the lens to infinity at the start makes everything more logical when you get inside and then want to put the thing back together.

 

using a dremel multi tool grinder wheel to shave off the stopper on the inside face of the plastic outer housing is easy as long as you take it slow with the dremel on minimum speed to ensure you dont grind right through the plastic.  you need good light and a nice work area. you just need to make sure you choose the right stopper to grind off (there are two - one for infinity, and one for minimum focus).  if you dont have a dremel tool, you could even shave the stopper off slowly with a scalpel in thin layers - the plastic is easy to cut away at. 

 

once you are modified, the original minimum focus distance was where the red line lines up with the '2' on the metre scale.  

I read the idiot in charge of RED claims his piddly little s35 'dragon' sensor will out perform super70mm film...   Same thing.  A bloke in a very strong position making suggestions that the red would come somewhere close to being able to shoot Zulu and other epic movies where only a large format will cut it.  Exactly the same as the people who think a camera phone can replace a proper camera, but he is setting an example and educating future professionals.  I'm not watching The Hobbit purely because the hype has put me off.  I'll stay at home and watch Ron Howard and Lucas's Willow instead.  

Just tested again.  seems maximum  'optimal' additional focus throw adds slightly over 1/4 of a turn extra to the existing 1/2 turn as you get on a standard iscorama 36.  so total throw is 3/4 of a full turn.  it will go a full turn, but you get a bit of wobble due to what feels like a lack of thread to keep the two parts linear.  I am going to set my new stopper to 3/4 of a turn away from infinity.  This gives me about 1ft closer focus than a standard iscorama 36 with the +0.4 diopter, and probably about 2-3ft closer than the standard iscorama when not using a diopter.