02/22/2006 09:11:19 AM · #1
|Wow, Well I spent 45 minutes writing this post earlier, but it got LOST in the rollover :(. Here we go again.
OK, so I have recently been considering different options on Tripod Heads and in checking out the differences, I have realized a few basic uses for tripods.
Mostly, they are used for stabilizing the camera for long exposures/low light stuff, stabilizing for long focal length shots, stabilizing for extremely exacting control of depth of field and providing a solid base for references with Panoramic shooting.
Now of course, I'm not a really high end photographer, but I figure if I'm going to go this route, it would really pay to get the most out of my money for what I want. That way, I'm sure to have the most flexible solution.
So I decided that my requirements included a head strong enough to hold a fully loaded 20D with BG and a moderately heavy Telephoto lens.
In the process, I discovered a few interesting things about the working of Panoramic rigs. Foremost, they are EXPENSIVE!
I do shoot casual panoramics now and again using the latest version of Photostitch that came with my S2 (it's decent because it has the ability to "nudge" stitches which I believe my earlier version (with the Powershot S30) did not have), but have never really put a lot of work into making serious shots. I do like to shoot in Portrait orientation for the obvious 50% gain of vertical resolution, but I have since seen a couple of rigs and done a bit of reading.
I guess flipping the camera sideways on the old 40 dollar tripod isn't quite as good as I thought ;).
I was checking stuff out in a totally awesome camera store in TaiZhong a couple of days ago and discovered a really useful little device which I feel will help me to get what I need. My second visit to that store was even better. While I was there, I had a chance to show my little contraption to the store owner who had reluctantly sold me the vertical slider, insisting that it would not be suitable for what I wanted to do with it (he sold it anyways because it was just old stock collecting dust). While taking 30 seconds to show it to the lady who had been helpful in the store, this other customer walked up and took great interest in what I had made. Turns out he is the owner of Tamron Taiwan. When he saw what I had done and I told him what I had paid to get it made, he was shocked and stunned. He immediately pulled out his wallet and bought the other remaining slider. He actually had everything BUT the measured slider. He will be using it to check lenses for high tolerance, extremely low DOF issues. Woo!
I thought I would share my info with the rest of you guys too.
Portrait Orientation. In order to take good pano's, you are going to need something that will give you a reliable, fairly strong/rigid mount that allows you to center your lens with the center axis of rotation.
Normal 90 degree L mounts for this are quite expensive, ranging from 50 to 150 dollars US. Yikes.
I went to the hardware store and picked up a 4-pack of metal L brackets ($2.50 US). I was then able to take the brackets down to a machinist who cut the middles out as shown in the below thumbnail (each side previously had 2 single screw holes). This gave me the ability to make a sliding adjustment left and right as well as a somewhat perfunctory up and down adjustment (in retrospect, I could have just had the one hole drilled out to make a more solid link, but I suspect the difference is minimal - also, if I were using just one camera, and one setup, it is likely that I could have done without the sliding for the left and right, merely making proper measurements and drilling a single hole... I find it better to be more flexible and I will probably use this setup with 3-4 cameras). The machinist didn't want to charge me anything for the work as he felt it was too easy and he was a really nice old guy (his Chinese was pretty bad too, a real blue-collar country worker, but super nice). I gave him around $8 US for the work anyways.
Finally, I mounted a Velbon Magnesium mounting plate (model QRA 635L (B)) which is the system I will be using with my tripod. Being a magnesium plate, it is 30% lighter than aluminum and stronger and more rigid as well. Recommended product (by me). This cost me around $25 US.
Obviously, this setup isn't as rigid as it could be, so I decided I would get more strength out of it by installing a washer as a spacer between the two L plates and using a nut and bolt to really firm things up. It's easily strong enough for my rather light S2 IS (around 0.5kg), and a preliminary test indicated that it did not bend all that much with a test weight of around 3kg (roughly equivalent to a 20D plus BG plus an 80-200mm F2.8L)
Total cost for the L mount assembly: $35 US (ish)
I will assume that if you are reading this, you already understand that to do Pano shots properly, you must place the optical center of your lens directly over the Axis of rotation for your tripod head. This is done by measuring from the Sensor plane forward by the Focal Length (the actual focal length in the lens, not the equivalent focal length... my S2 has a 6x crop, so I have to take a photo, remove SD card, check focal length in the EXIF data on my PDA, then divide by 6 to get the actual focal length). The sensor plane is marked on DSLR's with a line through a circle. It is usually a few mm behind the center of the tripod mount, but it's up to you to measure. On the S2, I will need to find that out, probably via an email to Canon.
With a solid mount, this will require the use of a measured slider that is capable of some level of precision. I've seen some cheaper sliders out there that are not marked, and they would work just fine if you stuck a plastic ruler on there with tape or glue and made a reference mark on the static part of the device that mates to your tripod. It is important to make measurements from your Sensor plane to the center of the tripod mount screw hole at the 0 point on the base of your slider.
A further concern is that some QR plates have a sliding screw. It would be wise to slide this screw all the way to an extreme (Thumb 1) and make the measurements from there than to deal with trying to eyeball a center or eyeball an alignment with the sensor plane mark on your DSLR (Thumb 2).
Sliders are not too expensive, but can be quite heavy and are certainly not cheap. I saw a good two-directional slider by a Taiwanese brand without markings for around $75 US, and I saw a couple sliders by Giottos that were from $60 to $80. I found a vertical slider by a company called King (?) and was able to remove the camera mounting attachments that made it vertical and even was fortunate enough to salvage a couple of 1/4"-20 thread screws that came in handy too for around $30 US.
Total cost for issue 2: $30 US plus fifty cents for some nuts, bolts and washers to put it all together
Running Total: $65 US
Please note that the images are a little soft as I took them in a bit of a hurry. I'm still waiting on my Giottos head, so I mounted it to my old $30 cheapo tripod.
Centered and leveled Panning rotation.
This is where the dollars can really start to add up. Many tripod heads do not include a separate adjustor set screw for the panning rotation as well as the ballhead. This means that if you want to rotate, you will loosen your ballhead at the same time. The Gitzo 1278 (rated for 6kg, but nearly 600g) has separate tighteners. So does the Giottos 1002 (also rated for 6kg, but weighs only 250g without a QR mounting plate).
The problem is of course that the heads are engineered backwards. If you want to pan properly, you will need that rotation to be on a plane that is in line with the horizon, or in other words, level. This means that with a normal mount with either the Gitzo or the Giottos, it is necessary to level the main tripod body before making any rotations. This is a serious pain in the rump for most people because you then need to make sure your ballhead is level, then your camera itself. 3 checks. Most people serious about Panoramic shooting get a separate rotator that mounts on TOP of the head, eliminating the leg adjustment. However, this is QUITE expensive and can easily end up with you spending as much for that toy as you did for the entire tripod and head... OR MORE!
The solution is simple though. Mount the tripod head upside down. This is not a new idea, there are a handful of inverted ballhead type tripod heads already out there. Hakuba makes a fairly cheap one, as does another company that I forget that sells for rather a lot of money on B+H. None of these options come with a top mounted rotator though, so this still leaves you out in the cold as for cost.
I have decided to go with the Giottos 1002 model myself ($59 on B+H), but therein lies another obstacle. The top screw of many models is removable which reveals a female slot, often a 3/8"-16 thread screw. This is not the case on the 1002 model. (sorry, no pictures yet, the 1002 is back-ordered. I will pick it up tomorrow afternoon)
There is good news though. Most tripod center shafts are designed to be removed and inserted upside-down to allow you to mount the camera underneath the tripod for lower-down shooting. They also usually feature a thread on the inside of the shaft. This means that it is theoretically possible to get a peice of aluminum made that allows a similarly sized peice of aluminum pipe to be inserted that has a FEMALE 1/4"-20 thread to accept the end of the 1002 head. It should then be possible to get a male to male 1/4" adaptor that will allow me to mount the Velbon QR mounting plate on the BOTTOM of the Giottos 1002 (or directly mount the 90 Degree slider device)
It will then be a simple matter to level the top of the tripod and lock it in place thanks to the ball-head. I will then have total control over the rotation without having to buy another device or tripod head.
I believe that all of this can be done with access to a basic hardware store and a reasonable machine shop. And it can be done for a FRACTION of the cost that would normally be required. The total weight of the assembly will also be significantly less than most Pano rigs I have seen so far.
Total cost of Issue 3: $45 (my price for the 1002) $## for the machined Invert Mount attachment.
In the end, it is also likely going to be important to add a Hotshoe extension so I can really get the thing level at the camera. (the S2 doesn't have a hotshoe mount. These toys cost only a few dollars and could easily be used as a screw to attach the QR plate to the 90 degree converter.
Please note that I am not an expert, just a hobbyist like so many others out here. I don't even take very good photographs ;).
Please feel free to comment on anything I may have missed or post details of your own Pano rig so we can have a thread that is useful for reference for anyone interested in the topic.
Message edited by author 2006-02-22 09:32:40.
02/22/2006 09:56:50 AM · #2
|Nice post - You are a "Tinkerer" like me!!!
I wouldn't have allowed that Tamron guy to get away with your idea though - I would have told him it's Patented! It'll be in the shops by summer with a Tamron badge on it!
02/22/2006 10:18:02 AM · #3
|Larf. I think he has a mind to use it to do things like checking lenses returned for warranty. Manufacturing for Tamron is probably done in Japan or China or something. I'm pretty sure they don't manufacture in Taiwan.
I was an idiot and didn't ask for his business card though. I will probably buy a Tamron 28-75 one day.
If they do release it, they will have to fight King for patent rights.
Actually, I'd be pretty glad to see something like it in stores by summer with the Tamron badge. The concepts are not what are difficult here, it is getting it done cheaply.
You could easily spend over 600 dollars US for a setup like what I am making. I'm pretty sure I can get the whole thing finished for just under $150.
03/04/2006 01:34:14 AM · #4
|So I finally managed to get everything put together yesterday.
Oh what a joy to finally get things worked out.
The key to my success was finding a way to mount the Giottos head to the bottom screw-cap (which is made of high density plastic of some sort, quite strong and rigid with a fine, deep thread).
This was accomplished by the use of a special washer found in a Gitzo store's bag of tricks which was then drilled out to accept a special brass Female 3/8 socket. I used a 3/8 to 1/4 adaptor to thread the head mount screw into it and a simple 3/8 bolt to mount it securely.
I had to use a couple of washers to make a good secure, properly spaced mount.
It now looks like this.
As you can see, I also had a chance to add a Velbon Magnesium QR plate to it. Of course, this is mounted upside down. This was quite an obstacle as nobody I talked to in more than 25 camera stores (!!!) had any idea how to accomplish this or where to find the screw.
It seems that it's simpler than I thought because flipping something upside down, doesn't change the direction of the thread. A solution was found at a bolt store in the form of a 1/4 thread 3mm allen key stud. It took me nearly 2 weeks to find this item which is rather shameful on the part of the local camera stores IMHO. The reason it took me so long to find it is in no small part due to the obscure location plus the language barrier.
Now I am able to level my tripod head perfectly WITH the plane of rotation!!! I did not have to add any extra special equipment. It all comes down to a quick and easy SINGLE adjustment at the ballhead.
One thing that does come up here though is the fact that when dealing with rotation, having a level plane in two axes is not sufficient for absolute perfection. For my purposes, it's pretty blinkin' close. You can check for offset by gently rotating the head throughout a full circle and see if it's close enough for your purposes too. I leveled 3 times and I am going to guess that I was off less than 0.5 degrees from level. Five seconds to adjust the head each time.
Another thing that could be done is to mount a bubble level somewhere on the slider apparatus for those occasions when you want to shoot pano stuff. I can't personally be bothered for the amount I will use it.
The next logical step is to add the slider apparatus which is useful for Macro shooting (manual focus) and the aforementioned Pano setup.
An important issue here is making sure that your L mount is also perfectly square. Using the cheap method I have, this is less than certain.
For this, it is entirely possible to mount a simple extension type flash hotshoe mount and use that as the mounting point for your QR plate. These cost very little. 10 bucks maybe.
Then it is possible to add a spirit level (either bidirectional or circular, your choice) to double check that the camera is also level and therefore in plane with the axis of rotation.
There is also a device made by Stroboframe that is probably stronger and more reliable than the little L plates that I have. This is a great way to go for those who use multiple cameras or go shooting with friends.
Finally, I will say that it seems that a 6kg head is going to start encountering strength issues for a DSLR any heavier than 2kg when using the slider. It may be possible to rig some form of counterweighting and still be ok. In addition, It seems that longer focal lengths are going to need a bit more serious setup. I can get AROUND 14cm of extension from the focal plane of a DSLR, which translates into a 140mm focal length. As stated before, this figure is applied to the lens itself before the crop factor is applied, so you will end up with around 220mm effective focal length with a 20D/30D.
In summary, if you want to do something like this yourself, and you use a heavier camera, I would recommend a minimum of the Giottos 1001 (8kg) or 1000 (10kg). These tripod also feature a removeable mounting stud which can allow you to directly mount the head upside down.
You can then install a QR plate upside down of your choice and you are pretty much off to the races to find a slider which you can mount your Stroboframe rotator to. Total cost should be up from USD 150 to 200 depending on the slider you get.
Hope it helps!!!
My total cost for everything was 3900NT which is about the equivalent of 115 dollars US. If you count an extra set of Velbon mounting plates, that brings it up to 5300NT which is about 155 dollars US.
Message edited by author 2006-03-04 02:10:37.
03/15/2009 01:25:24 AM · #5
|heh. Funny thing. I was checking to see what is going on with my thumbs all disappearing on my archive threads and i discovered that Arca Swiss has switched their new line of ballheads to the inverted type too.
I wasn't the first though of course, but it does show the relevance of this method.
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