Discussions (52011)

[Zombie thread] FOUND SOLUTION TO BANDING / UNUSUAL NOISE - Cactus PT-04 / v2s / gadgetinfinity

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OliverDavidPatrick says:

Ferrite ring keeping interference away from hotshoe

Ferrite ring keeping interference away from hotshoe 2

click for details there are many notes on the second one
Originally posted at 3:42PM, 4 July 2008 PDT (permalink)
alohadave edited this topic 114 months ago.

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rudy__ says:

Right solution but the device you used ferrite and not a magnet. A magnet produces a magnetic field without electricity. The ferrite is adding impedance (resistance to AC frequencies). If it were a magnet (and I really doubt it) you can test it by putting a piece of steel along side it. If it doesn't pull then it is not a magnet.
Originally posted ages ago. (permalink)
rudy__ edited this topic ages ago.

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rudy__ says:

When I first heard of the problem I thought that this would be the solution. Since I don't have the problem I was unable to find a solution for it. I'm surprised no one had tried this before now. Way to go.
Originally posted ages ago. (permalink)
rudy__ edited this topic ages ago.

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OliverDavidPatrick says:

Yeah well, anybody who has experienced the problem and reads "banding" in the title will find this helpful.

After all the banding occours in similar patterns yet on different cameras, so there is an analogy.
Originally posted ages ago. (permalink)
OliverDavidPatrick edited this topic ages ago.

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Andrés Martín / Tincho says:

And what would happen if you connect it with PC cable and those hot shoe adapters putting the cable through the Ferrite ring... I think it's the same but you don't need to disassembly the cactus...
ages ago (permalink)

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rudy__ says:

Could work but it is far less convenient to use.
Originally posted ages ago. (permalink)
rudy__ edited this topic ages ago.

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OliverDavidPatrick says:

That will work, Tincho. The ferrite ring acts as a filter and just needs to be placed somewhere along the connection between camera and transmitter.
ages ago (permalink)

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david farley says:

I don't know of a digital camera that will sync at 1/500 - even the new, high-end Canon's only sync at 1/250.

By "banding" do you mean that half of your photo is dark?
ages ago (permalink)

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(the original) strobemonkey says:

davidmfarley - I know hwat you mean, but what you describe is different which is caused by too fast shutter speed. The banding they are referring to is experienced by 5D users which is some sort of interference lines in the pictures when taken with the cactus trigger.
ages ago (permalink)

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Nionyn_ is a group moderator Nionyn_ says:

Cool.
I posted some time ago about a thread I'd seen on on dpreview, but that was as a 'cure' for misfiring.
Here:
www.flickr.com/groups/strobist/discuss/72157604001268871/...

Have you found that integrating the ring into the unit affects the misfiring rate at all?
Cheers, Nionyn
Originally posted ages ago. (permalink)
Nionyn_ edited this topic ages ago.

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rudy__ says:


I posted some time ago about a thread I'd seen on on dpreview, but that was as a 'cure' for misfiring.


Same kind of problem but different end. With the misfiring you are trying to isolate the flash from the receiver. With the banding problem you are trying to isolate the camera from the transmitter.

Thankfully I have not experienced either problem. But as far as the false triggering I'm not using the hot shoe type receivers. And most of my flashes are low tech designs that probably don't create interference high enough in frequency.
ages ago (permalink)

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DPoem says:

David. My Nikon D40 syncs at 1/500. I think it's the only Nikon DSLR on the market that has that high sync speed, though.

As for the banding interference, that's actually what it is. It's a sharp ribbon of noise running across the image.
Originally posted ages ago. (permalink)
DPoem edited this topic ages ago.

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PVignau says:

Well D70 and D70s also sync at that speed. and faster. I got nice results at 1/800 and 1/1000. You have to use remote flashes; your camera must not know a flash is in use. This means manual mode on the flashes and some triggering device (hence the V2s).

Oh and thanks for the tips on the banding and misfire!
Originally posted ages ago. (permalink)
PVignau edited this topic ages ago.

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kd5jha says:

This is a common problem with many of the products beig manufactured in China and Hong Kong...

I recently had a discussion with an engineer from China who was in the US on business...and he was telling me all about how that their was no need for me to spend extra money on ferrite chokes and other types of filter devices in my products unless I was not confident in my designs and my own engineering talent.

That could be the case, but obviously there are not enough talented engineers over there either :) because I keep getting crap from those countries that puts off lots of RF Trash and other Signal Interference that could easily been filtered out using common techniques that have been known to the engineering community for decades.

They just leave the stuff off because they are CHEAP bar none! That's why they sell direct from Hong Kong...less FCC red tape over there :)

RMG
ages ago (permalink)

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Nieblung says:

@DPoem, I also think the D70/70s syncs at 1/500. But I think you are correct in saying that the D40 is the only new camera on the market that syncs to 1/500.
ages ago (permalink)

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gypsy_dreamer23 says:

My D40 syncs at 1/500 with my SB-24, and it will sync at 1/1000 with the the Minolta 132x flash I just picked up, but only if it's on camera... I haven't tested the sync speed off camera, though.
ages ago (permalink)

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david farley says:

That's cool that the Nikon's sync at such high speeds... I stand corrected.

strobemonkey - thanks for the info.

This group is filled with very talented and intelligent people. None of you guys fit that description, but they're here.










(just kidding)
ages ago (permalink)

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**Ewie** says:

Sony A100 syncs upto 1/4000sec off-camera using Sony HVL-F56AM flash in wireless mode (line of sight). Have just recieved Cactus Triggers and best I have managed so far is 1/1250sec but working on a mod/hack that (might) allow higher.

Thankfully no banding... :o)
ages ago (permalink)

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OliverDavidPatrick says:

@davidmfarley:
uhm, no. what you mean is something totally different.

Please use flickrs search engine with the keyword "banding", jump over all results that acutally have to do with some rock band shooting and you should get to some threads where you can actually see pictures of the banding occurring.

The ability to sync at high speeds has got nothing to do wheter it's high end or not. The 5D, a camera with groundbreaking image quality can only sync low because of its stupid curtain shutter (why canon ?)


@Rudy216:
And most of my flashes are low tech designs that probably don't create interference high enough in frequency.

the interference isn't caused by a flash unit but by the transmitter when it's sittin' on the camera.


@everydoby else:

Guys, this thread is only for ppl who experience banding with their cactus.

If you are looking for advice on sync speed or high shutter sync speed please use flickr's search function.
There are already gazillion threads about off camera sync speeds.

It's just totally annoying to ppl who have the problem and wanna got throught this thread and all you read is kinda OT stuff about max sync speeds.

Not nice, put your stuff to where the topic belongs n please stop violating this thread with sync speed issues.

Thanks

EDIT: it would be nice if some moderator could close this thread as it seems nobody is actually capable of really contributing to the topic. (banding)
Originally posted ages ago. (permalink)
OliverDavidPatrick edited this topic ages ago.

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rudy__ says:

Maybe if you include in your original post an example of what banding is. And yes the topic has deviated to interference on either end.
ages ago (permalink)

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Andrew Smith (Meejahor) says:

Oliver, or David, or Patrick, or whatever your name is, you seem to be a rather condescending fellow. Lighten up! (Off-camera lighten up, of course.) Spam is commercial messages, whether email or forum postings. People deviating from your intended topic of discussion are not posting "spam", they're just adding their own (related) viewpoint which you don't agree with.

What a stupid way of doing things, asking people to email you for the solution. Why not just do what everyone else does and post the information publicly? Easier for you, quicker for everyone else.
ages ago (permalink)

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OliverDavidPatrick says:

Hello Andrew,

It's not that I agreed or disagreed with users on their sync speed issues.
Max sync speed is simply NOT the topic of this thread and doesn't belong here.

Regards
ages ago (permalink)

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rudy__ says:

I agree with Andrew.

While I understand your frustration about the thread deviating from the topic I think you are overreacting by removing the information you posted. I think the information was important.

Maybe its time for someone to put together a web page that includes the important issues and fixes with these devices.
ages ago (permalink)

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The Red Giant says:

Maybe you could send DH a message and ask if he'll lock the message after you put it up?
ages ago (permalink)

obtainable cap [deleted] says:

Here's how I solved the banding problem on my 5D. I sold the Cactus and bought Skyports. Voila! No more banding, better reliability and construction. :)

And seriously dude, relax. If your original post was clearer about what banding you were talking about - CMOS interference banding vs. sync speed banding - maybe the sync speed posts wouldn't have happened. But getting pissed and taking your toys and going home is a bit much.
ages ago (permalink)

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The Lawgiver says:

So, is this problem occurring only on the 5D?  Has anyone seen it on the 30D?

I just ordered some Cacti! 
ages ago (permalink)

obtainable cap [deleted] says:

Bowen, here's the original thread. It seems to be mainly a 5D issue, though a couple people had issues with the xxD Canons when they modded the Cactus to increase range. But the unmodded Cactus doesn't seem to cause problems with the xxD.

www.flickr.com/groups/strobist/discuss/72157603230295239
ages ago (permalink)

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dwang2010 says:

We're getting base sync speed and TTL-high sync speed confused here...

When you use TTL flashes (SB800/600 on the Nikon, HVL-?? on the Sony, EX flashes on Canon, etc) on the corresponding bodies, high speed sync is enabled, but sucks up more power and recycle time.


@BowenPhoto:

Do a quick search of "Cactus" "30D" and "Banding" turns up little and it would seem that the issue only effects 5D users however there are reports that a few 30D users, and even a reported Olympus user sees this problem.

There is even a Strobist post that touches on the issue.
strobist.blogspot.com/2007/11/gadget-infinity-canon-5d-is...

I own Cactus triggers and a 30D, and have used it on 2 or 3 different 30D's and none have experienced the issue.

(Lesson of the day? SEARCH PREVIOUS THREADS.)


Thanks to the OP for finding a solution, I'm glad to hear someone is working on it.
Originally posted ages ago. (permalink)
dwang2010 edited this topic ages ago.

obtainable cap [deleted] says:

"As stated the topic at hand is **native sync speed** not TTL-based High Speed sync. "

Umm, actually it's not. The topic is a solution to banding caused by CMOS interference of the Cactus triggers. The OP stormed off in a huff because people started talking about sync speed, native or high speed.

Lesson of the day. READ THE THREAD. :)
ages ago (permalink)

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dwang2010 says:

My mistake, I just focused on the confusion between native sync speed vs. ttl-high speed sync. Thanks for catching that sorenson.
ages ago (permalink)

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OliverDavidPatrick says:

I've been out shooting till now, while in the back of my head trying to figure out what interference banding has to do with sync speed and some curtain shutters.

If you have visible banding in your images because of the cactus trigger, then it will always be there and you'd want to get rid of it entirely. So I don't really care about at what shutter speeds it occours mostly, I want it gone.
Thanks Entropy512 for the lead, the interference causing the banding emits through the hotshoe into the camera caused by the transmitter.
Maybe it's more visible here and less there depending on the shutter speed of the shot and whether syncing the shutter front or rear.

Most people notice it like me, when they have to push the RAW brightness of some underexposed keepers in postproduction.
Sometimes though it also occours in good exposed shots as freaky colour noise.

Once again (and it sure is sad enough I have to be this clear):
Banding does not mean the partly black image you get when exceeding the native sync speed of your (mostly) curtain shutter DSLR. The black thingy you see there is one part of the curtain shutter.

All you need:
-some small round magnet
-cable to extend the connection from hotshoe module to the board and tangle around the magnet twice

Ferrite ring keeping interference away from hotshoe 2

Ferrite ring keeping interference away from hotshoe
Originally posted ages ago. (permalink)
OliverDavidPatrick edited this topic ages ago.

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rudy__ says:

Once again, these as not magnets. They are magnetic material though.

They are as much a magnet as a piece of steel is a magnet. A piece of steel will support a magnetic field but once the current disappears the magnetic field also disappears.

Look at the following under soft ferrites, this what is needed. en.wikipedia.org/wiki/Ferrite_(magnet)
ages ago (permalink)

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OliverDavidPatrick says:

Thanks for correcting me, rudy_216 - I should have paid more attention in physics class.. :-)
ages ago (permalink)

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Adventures Into The Unknown says:

yup, looks like rf interference, i guess the transmitter is also using the camera connector cable(and thus the camera) as an antenna, the ferrite would "filter" the signal. any other cheap triggers show this? has the mod improved the reliability? what kind of range are people getting in practice?any ebay ones significantly better/worse than others?

(if its too off topic)
www.flickr.com/groups/strobist/discuss/72157605994780166/
(has anyone modded the transmitter to triger by sound?relay?)
ages ago (permalink)

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OliverDavidPatrick says:

The big big downside is that these triggers don't have digitally coded channels, that's why they are so cheap. All other bugs can actually be solved.

But seriously, if you have clients who pay you money your gear needs to perform. If your lights fail and you can't deliver any work your client wont care that your triggers "almost" perform as good as the PWs at only a tenth of the cost.

Also imagine yourself in a situation where there are other photographers around you using their ebay triggers. The risk that somebody will go firing your flash is just too high. You need the digitally coded channels of the PW ! Jeez, I wouldn't even dare show up at a strobist meetup with the Cactus triggers.

Back to your questions:

Installing the ferrite ring didn't decrease performance in the slightest.
If you like to do interior photos and are in to cool stuff like placing strobes outside and letting them shine through a window or placing strobes in hidden corners you will need an antenna. I recommend to install a vertical antenna and disable the onboard horizontal antenna with a dremel or a saw.
Originally posted ages ago. (permalink)
OliverDavidPatrick edited this topic ages ago.

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energumeno. says:

good find!!

Any toughts on where could i get a small ferrite ring to do this mod?
ages ago (permalink)

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glaschu says:

From a small, married ferrite?
ages ago (permalink)

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David Sr. - says:

One place to get them is tear apart those electronics before you toss them in the trash, Boom box's/Cassette players, etc. They often contain ferrite beads.

Retailers:
Digikey, dkc1.digikey.com/us/digihome.html
All Electronics www.allelectronics.com/make-a-store/item/TOR-54/FERRITE-T...

R/S used to sell an assortment of sizes, they pretty much only sell Cell phones and toys these days! :heavy sigh:
Originally posted ages ago. (permalink)
David Sr. - edited this topic ages ago.

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kraig7777 says:

Great thread for 5D users! (I'm a low end Nikon guy but a 5D has always been on my dream list).

Anyway for what it's worth, the only Nikons with the 1/500 native sync speed are the 6.1 mp sensors, which luckily includes my nifty D50.
ages ago (permalink)

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Jolly Joker | www.i-am-jollyjoker.com says:

Unfortunately, I tried this method, but I still have banding noise in some of my shots. Sometimes when I shoot RAW, the RAW file is damaged totally and can not be opened.
This is how I did with my triggers:

I'm planning to add a metal box around the transmitter, only leave the antenna outside the box, in attempt to prevent interference. Or, there's also another way: Use the sync cable included with the transmitter to connect the transmitter to camera via PC sync port, and use an extension cable to place the transmitter far away from camera, maybe this will work.
I'll try these methods soon and will let you know the result. Anyway, I've ordered some Cybersyncs as replacement because I got pissed off too much with these crappy PT-04, I don't know when it will damage my camera, I can't take the risk.
Originally posted ages ago. (permalink)
Jolly Joker | www.i-am-jollyjoker.com edited this topic ages ago.

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DaPi ♫ says:

I've heard of people having problems with the receivers giving spurious triggers but only when attached to the flash - a ferrite on the receiver-to-flash cable might be worth trying in that case too.
ages ago (permalink)

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velja123 says:

has anyone actually tried this with canon 5D ?
Originally posted 114 months ago. (permalink)
velja123 edited this topic 114 months ago.

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