Hack Chat Transcript, Page 1

A event log for Camera and Lens Repair Hack Chat

Anthony Kouttron

tom-nardiTom Nardi 05/30/2024 at 03:060 Comments
Anthony Kouttron 2:49 PM
Hey everybody! I'm Anthony Kouttron, I'm an electrical engineer and big camera nerd. I have been repairing cameras as a hobby since ~2010 ever since mirrorless cameras began supplanting the 3CCD potato cams of the early 2000s. I've repaired full frame consumer cameras, cinema cameras, cinema accessories, and both zoom / prime photo lenses. Shoot me any questions you have involving camera repair, design troubleshooting etc...
Dan Maloney 2:51 PM
Hey Anthony, welcome aboard!
Anthony Kouttron 2:52 PM
Dan Maloney 2:53 PM
We'll give it a few more minutes to let people filter in then we'll kick it off
Dan Maloney 3:00 PM
OK, hello everyone and welcome to the Hack Chat! I'm Dan, I'll be moderating today along with Dusan as we welcome Anthony Kouttron to the Hack Chat to talk about busted cameras and lenses and how to make them un-busted
Dusan Petrovic 3:00 PM
Hi Dan
Dusan Petrovic 3:00 PM
welcome everyone!
Dan Maloney 3:01 PM
Thanks for joining us today, Anthony. THe reason I asked you on with us today was that cool repair of the Sigma lens that you pulled off. I thought it had a lot of neat tips and tricks:
Anthony Kouttron 3:01 PM
Glad to be here!
Dan Maloney 3:01 PM!
Dusan Petrovic 3:01 PM
Welcome Anthony!
Dan Maloney 3:02 PM
And I harped a bit about how much camera repairs scare me, but it's true -- I always shied away from trying to fix any of my SLR gear, even though I'll try fixing most anything else. Is that a rational fear?
Anthony Kouttron 3:03 PM
The biggest risk when tearing apart a camera is the flash trigger circuit and the sensor block.
Anthony Kouttron 3:03 PM
When disassembling a camera with a flash, the integrated capacitor will hold charge for a long time. There is not usually a bleed resistor
Anthony Kouttron 3:04 PM
so you have to properly discharge the capacitor before continuing with the teardown. The camera manufacturers actually talk about this on the first page of the service manual. Taking a 5w resistor and a few jumper leads takes care of it no problem
Evan None
but it is an essential step. I forgot to discharge the flash capacitor one time and my right angle tweezers touched the wrong place. my poor knipex tweezer tips were no more
Anthony Kouttron 3:06 PM
In regards to the sensor, if the camera does not have 5-axis stabilization, there are usually 4-6 spring loaded screws that are adjusted to make the sensor planar to the lens bayonet
ump 3:06 PM
What is the proper way to discharge the capacitor once identified?
these screws are calibrated at the factory before the camera is shipped. you do not want to unscrew these are you will not be able to verify sensor flatness without speciality tools. I'm sure it can be done, but you will likely need a light projector and some kind of light measuring device
Andrew Smith 3:07 PM
Hi Dan Hi Anthony, I've been collecting film cameras with a bit of repair for a while. I learned a lot from the books of Thomas Tomosy. Saddened to learn he passed in 2023
Anthony Kouttron 3:07 PM
I use a 10ohm 5w resistor with insulated leads. I simply put the resistor across the capacitor and it safely discharges the cap
transistor--man 3:08 PM
Thanks for hosting a hack chat, whats the best series of cameras in terms of repairability?
Anthony Kouttron 3:08 PM
obviously do not touch any bare metal wire leads, make sure the leads are indulated
Dan Maloney 3:09 PM
I've got a Canon A1 that I left the battery in for too long and it leaked. I've heard the battery box replacement is pretty straightforward, so I should probably start with that. The camera has a lot of memories for me
Anthony Kouttron 3:09 PM
Anthony Kouttron 3:09 PM
Hey @Andrew Smith Thanks for the info! I did not know him personally, but I'll check out his work! Camera repair is an interesting industry and it is even thereputic. Yes it can get involved, but it's fun.
Anthony Kouttron 3:10 PM
I started repairing lenses by tearing down the many 1970s clone lenses that were available at retailers like jc.penny, sears etc...
Anthony Kouttron 3:11 PM
they were usually dubious quality but similar build construction was found on fancier lenses. It's a way where you don't have to care about making mistakes on a lens with little value
ump 3:12 PM
When starting with lens and body deconstruction, did you purchase dead cameras and lenses to do so, or were your encounters more based on "Wow my device is dead and I guess I should try to fix it"
Dan Maloney 3:12 PM
YOu can pick up lenses like that for super cheap online and in the few remaining IRL camera stores
Anthony Kouttron 3:12 PM
@transistor--man That's a tough question, most of the manufacturers have service manuals, but olympus and fujifilm in particular do not have many service manuals floating around on the interwebs, which makes the repairs more difficult.
Andrew Smith 3:13 PM
I've got a sticky Mamiya-Sekor 80mm lens for the Mamiya C330 TLR Have you worked on those before? Any tips or suggestions?
Evan 3:13 PM
the timing of this hack chat is apropos - my 200-500 just stopped being able to zoom in. Apparently it's a common problem and an easy fix.
Anthony Kouttron 3:13 PM
@ump A bit of both! I came across a lot of 1970s/ 80s film lenses in poor condition and I started tearing these down and servicing them back to working order. It's amazing how old grease will make an aperture completely stuck.
transistor--man 3:14 PM
ive had issues with cameras in the cold, are there ways to keep them working on cold nights of astro photos?
Anthony Kouttron 3:14 PM
@Evan 200-500mm from which vendor?
Evan 3:14 PM
Evan 3:14 PM
Anthony Kouttron 3:17 PM
@Andrew Smith I have not worked on any mamiya-sekor lenses yet but being leaf-shutter lenses, they are more complicated to service. Folks do service them though! THe sekor-c lenses are highly coveted lenses because they can cover medium-format sensors well. They are often rehoused by TLS, zero-optik etc...
Anthony Kouttron 3:17 PM
transistor--man 3:17 PM
has lens construction gotten better over time or worse? are newer lens's less accessible for repair?
Anthony Kouttron 3:19 PM
@transistor--man That's a good question. I'd say, overall, lens construction has improved. There were pain periods where the main manufacturers experimented with composites and non-glass reinforced plastics and yielded to broken lens mounts and collars, but in comparison to the very sloppy, very poorly machined lenses in the 1970s, lens construction has improved
Anthony Kouttron 3:20 PM
what I will say is there is a stark contrast between proper cinema lens innerds vs consumer lenses.
transistor--man 3:21 PM
Do cinema lens's ever end up surplus? Ive only ever seen consumer stuff on ebay, but the large TV camera lens's are pretty rare
Anthony Kouttron 3:21 PM
cinema lenses often required parts to torqued town to specification and require the use of calibrated screwdrivers like the wiha TorqueVario Screwdrivers
Anthony Kouttron 3:22 PM
the mounts are torqued down like a car wheel. there are also offset cam lobes for fine adjustment of elements and lens assemblies in more expensive lenses that are not present on inexpensive consumer lenses
Dan Maloney 3:23 PM
"the very sloppy, very poorly machined lenses in the 1970s" That was all I could afford ;-( Although I did pick up a nice 135mm Canon lens used at a camera shop back in the 80s. Best lens I ever had. f 1.4, I think. Nice portrait lens
Anthony Kouttron 3:24 PM
more attention to focus consistency is placed on cinema lenses like the zeiss master prime / supreme lenses. the lens helicoid will often be one CNC machined piece of brass with dampening bits to provide a very dampened but solid feel. Focus slop is not a desirable trait on any cinema lens.
cho16888ol 3:24 PM
I am newbie to the camera and lens repair, any suggestion on how to get started besides the books from Thomas Tomosy suggested by Andrew?
Ferdinand Sanchez 3:25 PM
Is there precise range of image circle size defined for C mount lenses?
Anthony Kouttron 3:28 PM
@Dan Maloney Hahaha. Let me rephrase that: there was a great divergence in lens mechanics between large lens manufacturers and the clone manufacturers in the 1970-80s. I had a "best" brand canon FL breach lock style lens. The lens was assembled in two aluminum halves that did not even line up when assembled properly and the threaded screw holes stripped if you looked at them the wrong way. The nikon, canon etc... lenses of the 1970s features far better assembly standards and did not rely on guessing alignment. there were proper machined sholders and threaded rings that held down lens elements. Ironically, canon K35 lenses from the 1970s are insanely desirable even though modern lenses are better in almost every way
Anthony Kouttron 3:30 PM
@Ferdinand Sanchez C-mount lenses are tricky. There is quite the variability in image circle coverage and it facies from series to series and manufacturer. There is also the CS mount which is aimed at scientific applications and has a slightly larger image circle. Your best bet is to hunt down lens datasheets. They absolutely exist! Rodenstock / linos, schneider etc... all produce datasheets with mtf curves and image circle information
Anthony Kouttron 3:31 PM
@Ferdinand Sanchez for example:
Anthony Kouttron 3:31 PM
@Ferdinand Sanchez I believe there were cinema specific cs lenses made by schneider or another large lens vendor, I forgot the name.
Evan 3:32 PM
Any tips on dealing with loose focus grips? The rubber ring on one of my old primes is getting a bit loose.
Anthony Kouttron 3:33 PM
@cho16888ol Absolutely! My two favorites are mikeno62 on youtube and listening into the duclos-lens livestreams. Matthew Duclos is incredibly knowledgeable on lens repair and at this point, has seen the inside of nearly every cinema lens in existence.
Andrew Smith 3:33 PM
Anthony, have you serviced or come across radioactive glass? I was shocked to learn my Super-Takumar 50mm F1.4 used Thoriated glass and sent my DIY geiger kit off the charts. (I don't use it and would certainly never open it myself)
Ferdinand Sanchez 3:35 PM
@Anthony Kouttron Thank you! I am working on a action camera setup that uses M4/3 sensor, so i am hunting down quality wide angle C mount lens(of course not fisheye one - i am searching for low distortion one)
transistor--man 3:36 PM
@Andrew Smith did you know you can un-yellow thoriated lens's with UV?
Anthony Kouttron 3:36 PM
@Evan Rubber grips are tricky. Rubber that has aged or become impregnated by oil is hard to recover back to original shape. I have not found a solution that works. My 12-35mm f2/8 lenses that I use from panasonic have the exact issue you state and I have not found a fix other than removing the rubber lens grip adding heatshrink below where the rubber ring goes and reinserting the stretched out rubber grip. The grip diameter will be larger, but it will at least not feel sloppy when in use. Digikey is a great resource for heatshrhink. Adhesive heatshrink works best. Take your time when selecting heatshrink sizes, it's easy to measure wrong :D. If the lens you have is still recent, buy a new grip from aliexpress / taobao
Anthony Kouttron 3:38 PM
@Andrew Smith I have a few radioactive pentax lenses. They are fantastic to use and ironically I have not had to tear them down yet. I don't fuss over a bit of dust inside a 1970s-80s lens. Unless there is fungus or substantial internal problems with a film lens, I will not tear it down for a full "CLA" Clean, Lubricate and Adjustment
Anthony Kouttron 3:38 PM
@Andrew Smith I have too many other lenses calling for my attention :D
Andrew Smith 3:38 PM
Andrew Smith 3:38 PM
@transistor--man Yes I've seen that UV technique. Mine is definitely yellowing
transistor--man 3:39 PM
@Andrew Smith woah
Anthony Kouttron 3:39 PM
@transistor--man This technique is something I'd like to do myself! Don't tempt me to grab a few yellowing lenses....Oh well too late.
Evan 3:39 PM
🤔 I wonder if the radiation makes fungus less likely
transistor--man 3:40 PM
or stronger
Andrew Smith 3:42 PM
Thanks Anthony, thanks Dan. Gotta run but will check back in the chat later. Cheers
Anthony Kouttron 3:42 PM
@Andrew Smith Thanks for stopping in :D
Anthony Kouttron 3:44 PM
@Evan The 200-500 zoom repair you linked looks pretty straight forward and easy!. I'd go for it. The fellow sugests using electrical tape instead of the yellow looking tape nikon used
Evan 3:44 PM
no luck with that quick 200-500 repair process (none of the screws he mentioned seem loose), will have to research more, might have to take off the whole shroud
Anthony Kouttron 3:44 PM
@Evan I would highly suggest not to use electrical tape for this application. It will become gummy after a week. Use doublesided 3m tape. Hmm.
Evan 3:45 PM
it looks like kapton tape to me. I've got a roll of 1" kapton that I can use to replace it.
Evan 3:46 PM
when I watched the video I thought he was talking about that tape being used to hold the rubber grip down, but as far as I can tell it's just single-sided tape that holds the little metal covers in place
Anthony Kouttron 3:46 PM
@Evan I have not worked on that specific lens, but zoom lens repair can get hairy. The fellow made it seem like the kapton tape was doublesided. Zoom lenses often have many interlocking segments and they are not always accessible from one side of the lens
mark None
and the rubber grip is just held in place with friction
Evan 3:47 PM
yeah I'd go find a bunch more content before digging any further for sure.
Anthony Kouttron 3:47 PM
@Evan That makes sense. sometimes the front half of the lens is screwed in to the bayonet half, and the front lens beauty ring hides screws or a threaded collar
Anthony Kouttron 3:49 PM
@Evan in that case, you;ll need a lens spanner to disassemble the front element group or a cylindrical rubber grippy bit to remove the front lens facia. I linked a photo of what they look above.
transistor--man 3:49 PM
@Anthony Kouttron have you looked at the signaling for camera lens attachments, like M4/3 or E-Mounts?