Holga Blog

For the longest time, i overlooked the use of integral film. i passed on it, because all i knew was pack film and the peel apart medium. not to mention peel apart film was still being currently made and it was widely available, so it may seem, that i had no room to try integral film.  but then when the impossible project announced their intentions and imitate plans to roll out new integral film, i knew that i had to get an integral camera fast. i can only predict that the demand for integral cameras will sky rocket once TIP officially rolls out the new stuff.

i did my research and brushed up on some reading through the polaroid group at flickr, as well as the sx-70 group. i settled on a sx-70 after seeing, and lusting over it’s manual focus and classy good looks. i was sold. but wait, there’s more! because i’m a “slow” photographer, i wanted a tripod mount, only to discover that not all sx’s came with one. the alpha 1 variant of the sx-70 did. so 2 days later, i found what i had been looking for through and online auction place and placed an absurd bid just to make sure i’d win. one week later, and a short wait from customs. my baby arrived to me safe and sound from alberta, canada.

because i knew that there were a few ways to use 600 film on my sx-70, i looked at each method carefullly to decide what i wanted to do. the first method was to use an nd filter over the lens of the camera. it’s not permanent though you’ll have a dark viewfinder and this can be difficult if you wanted to shoot in low light conditions. that was definitely not for me. the second method involved buying or reusing an nd filter from a polaroid sx-70 blend pack, or cutting/using a premade made one to fit over the integral pack. sounds great, but i don’t wanna fiddle around with filters and fitting them over each pack that i have to load. the pro to this was that it still kept the camera physically unchanged and was not permanent. these two methods are pretty much very good ways to use 600 film, however for myself i wanted to  go the route of a permanent solution. as much as i wanted to retain the stock integrity of my new camera, i didn’t plan to ever use sx-70 film. now even if TIP released a new version. though this last method can be considered permanent, in my eyes it was not. but it also offered a more reliable and foolproof way of using 600 film.

this last method i thought and studied was to modify the RC circuit of the sx-70. this was truly a mod, and not a method. because of the complexity of this, i decided for the sake of this article to simply change out the inductance value (capacitor), and then test with a test shot from 600 film. if it fails, then i will go back and change the inductance value and/or the resistor value as well. it should be noted that this mod can be completed by anyone who is capable of soldering and capable of performing electro/mechanical disassembly. on a scale of 1-5, w/ 5 being complex. this is a 4 .i should also note that i take no responsibility or fault for any actions or damage that you do to your camera when performing this mod. this was written to give you a guide to what is needed and expected with this type of work. with careful planning and your method of work, this can be completed in a few hours. perform this work at your own risk.

tools needed:

• a DIY1mm x 1mm square drive screwdriver
• needlenose pliers
• tweezers (optional, but comes in handy)
• soldering iron (i use a weller wtcptd)
• digital multimeter (dmm) with an inductance feature ( i use a fluke 87 III)
• wire cutters
• painter’s tape (the blue stuff)
• solder wick (will be needed!)
• solder suction gun (optional)
• flux (must be compatible with your solder obviously)
• solder (i use kester lead free)
• flux cleaner (you must clean your solder joints after rework)
• capacitor/resistor (for this guide we’ll only be replacing the capacitor. should you go the whole RC filter circuit way, know that Resistance is opposite to Inductance. but to go this route, you’ll most likely have some basic electronics theory covered) the inductance (capacitor) value won’t be known until you remove the capacitor from the pcb. so more than likely you’re gonna have to make a trip to your local electronics supply place. for my capacitor, i was lucky enough to find it at fry’s electronics.

ok let’s get started. on the back of the shutter housing of the camera, there are 4 screws. because of the differences in where the camera was manufactured, some are held together by either torx screws (size t4), square drive screws (smaller than #00 robertson size), and some even philips.  i was the unlucky one and had 4 square drive screws on the back. not having a square drive screwdriver around, much less one small enough. i made one. to make one, you’ll have to sacrifice a small philips or similar size driver and grind it down on four sides. some digital calipers, a dremel or similar rotary drill tool, a vice and some safety glasses. this is pretty straightforward. grind down slowly and measure along the way. a steady hand and good vision are needed! once completed, you’re not ready to take apart your sx.

diy square drive screwdriver

remove the 4 screws on the back. be careful and brace the camera well as the bellows are susceptible to being punctured at this point.

once removed, be careful that the shutter housing/shutter doesn’t free fall. at this point the only thing holding up all that weight is the signal/power ribbon cable. tear this cable, and you’re done. the ribbon cable will need to be desoldered from the pcb to detach the shutter housing from the main camera body. you can either prop it up in place or hold it in a low level vice. to make things easier, you can drop the film door to make things more accessible.

warm the soldering iron. at this point your shutter housing should be secured for solder rework. to expedite the removal of the ribbon cable from the pcb contact points, use solder wick to take up the old solder. a solder suction gun can also be used, but it’s not as effective as plain solder wick. once removed, be careful to not drop the housing.

once the housing is laid out. look over the pcb and orient yourself to where the parts are. for notes on the parts of the pcb, click on the image. to see all the notes for everything go to my photostream with notes attached.

click on photo for important notes.

once you’ve got acquainted with the pcb, you’re ready to remove the capacitor. the capacitor is located on the opposite end of where our ribbon cable was attached. since the board is upside down, the leads to the capacitor are upside down as well. this means that the capacitor is underneath the board, and so you’ll have to gain access to the part, in order to remove and replace it. to gain access, you’ll have to pry up the board at the nearest end to the where the capacitor is at. in this case, looking at the board from the top, you’re gonna pry the pcb up from the left side. my pcb had a plastic tab melted over the pcb. in addition to this, the pcb is coated in a black conformal coating. the conformal coating prevents the components from corrosion, nothing more. why they did this to only part of the pcb, i don’t know. but you’ll need to scrape this crap off in order to get some soldering iron heat on it. use some copper solder wick, it’ll make a quick job of taking all the old solder out. if you’ve removed the solder correctly, the old capacitor will just drop inside the housing. if not, you can pry the pcb up a little (be careful when you pry it up, as the board has a 4 pin connector, and another connector on the opposite side of pcb holding it down. pry up too fast, or too strongly and you’ll snap these off!)

old capacitor removed. only the mounting holes remain. use copper solder wick to remove the old solder.

now you’re ready to put the new cap in place. at this point, i couldn’t go any further with my mod until i got a new cap. i took out my digital multimeter and measured the cap at 1.45 nf. in conversion, it’s 1450 pf. i used the “4x” rule and this gave me a calculation of 375 pf capacitor that was needed. i could either be dead on accurate finding something close, but ceramic capacitors in this range come in 330 pf and 390 pf. i should note here that the capacitor that i removed looked to be a multilayer ceramic capacitor (it has a hard plastic coating that a normal ceramic cap doesn’t). for more info on capacitors, refer to this link.

i had 3 choices to go in order to get my cap. or at least 3 places i could try. in my area, there was a fry’s, a radioshack and a electronics supply store. fry’s was the closest, so i went there first. booyah, i found a 330 pf, but no 390 pf. seeing that i didn’t want to drive around after finding this, i decided to call it and took my chance with this size. if my test shot came out like crap, then i’d hit up the electronics supply place.

remember that all sx-70s are different, and because of this, the electric eye on each and every single one is calibrated to a different value. thus their rc circuits are tuned to each individual camera. there isn’t a single common capacitor value for the sx. you’ll just have to desolder and remove yours to find out which size capacitor you’ll need. in my case, @ 300 – 390 pf is what i need.

now that i have my part, i’m ready to get back to work. a car wash and a snickers bar later, i’m back home prying up the pcb gently. i used an alligator clip to prop the board up while i slide the new cap in. you’ll need to tin the leads with solder prior to soldering them into place. and then snip the extra leads once you find the length you need. it’s better to have them long, and then trim again once you have them mounted in the pcb through holes. once that’s done, solder it in.

take your time, but not too much time. the less heat you put on the board the better. but too little, and you get cold joints.

solder back in the ribbon cable. work your way from the contact nearest the camera body, then out. this way the cable stays aligned and taught. this should go rather quick. “touch and go.”

congratulations, you’ve finished your mod! but before you close the camera up, clean up the board with some flux cleaner. rubbing alcohol can be used. be careful of the lens if you’ve left it uncovered. and since you have access, clean up the back of the lens while you’re here. make you final check and put it back together.

the 1st test shot. success.

references:
sx-70 disassembly
polaroid group
sx-70 group
capacitor ref.
simple, simple faq
my mod photo set
*i am a electromechanical engineer by trade, and have certification in both class iii and class iv soldering. if you have any questions or comments, or need help on your mod, please comment below. and thanks for visiting holgablog!