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Forum: Photographic Technique
04-15-2010, 06:04 AM
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Hi edward,
I'm glad you like the aesthetics - I personally find it has a very 'mad scientist' feel to it.
In order to set it up for a specific camera lens combo, one must find both the correct 'rotation' of the hinge and the length of the track - this took a bit of trial and error. But once I had it set up for one lens, its a fairly simple matter of moving back and forth on the track to set up additional lenses. So its pretty flexible in that regard - although changing bodies requires a full set up again.
As for taking photos, it is as you say both times - the 'wheel-rail' rotates on the (level) tripod, and the next row is taken by moving the 'wheel-rail' up (or down) to get the correct elevation. Then the panning is done at the tripod-bracket join.
The camera 'hinge' point remains fixed - the points of rotation are all at the 'slide/bracket' point - that funny looking thing at the bottom.
Hope that helps!
Frith
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Forum: Photographic Technique
04-11-2010, 04:17 AM
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Of course its a good thing!
Sometimes I consider that perhaps this photo is a little noisy - can I stretch the shutter speed to get it down to ISO 100, or should I stop down a little so the edges of the lens don't affect the image quality too much.
Then I remember - most of my favourite photos were taken at ISOs below 200! And the lenses and kit we have today is absolutely amazing compared to what was available 50 years ago. Do you think if you took your 'photo lab' back to the 1950s that they would say 'no, we don't think all that new compact tech is any good - we want to keep photography alive as a profession'?
Its a fair cop that for those who really love it enough to want to make it a full time job, its getting harder - but that is true of many industries today - and these industries get replaced by other skilled industries. What remains is that there is a growing quantity of high quality images - by good luck or good planning - that means many more can enjoy this wonderful hobby, both as 'lookers' and as 'takers'.
And as mentioned above, there will always be a market for highly skilled photographers, similarly there will be a market for skilled web designers, 'photoshoppers', printing specialists, teachers, salespeople, artists...
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Forum: Photographic Technique
04-09-2010, 09:33 PM
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So here is the part you have probably been waiting for. After all that consideration of the design, this turned out to be fairly straightforward. I don't have many photos of the build, but that would be pretty boring anyway I think.
A lot of it is old bike parts, principally because that is what I found lying around in the shed...
Parts:
1 old bike wheel (diameter ~440mm) [larger would also work, but smaller might be pushing it]
1 old bicycle seat post clamp (the bit that attaches the seat to the post)
1 length of brass tubing (~5mm diameter, ~400mm long)
150mm of M10 threaded rod (found in hard waste, a bolt would probably be fine)
2 short M10 bolts
1 smallish bolt - this will be hand-tightened, and I was lucky enough to find (what I think to be) part of a clamp - its threaded on one end, and has a large flat section that allows for easy hand tightening on the other end.
1 'slide' - I used a mounting bracket that comes from some strange thing. Its drawn in the attached figure
2 large washers - small enough to fit inside the rim of the wheel, but larger than the overhanging 'lip' of the inside of the rim. They should stay captive but sliding inside the wheel rim.
4 M10 nuts
1 short length of pipe, ID ~10mm (the M10 threads need to slide freely in this, but not too loosely)
1 length of wooden dowel - fits snugly into tripod center post, and the other end will fit into the slide.
--- camera platform ---
1 length of acrylic (plywood would likely work just as well)
1 1/4" wingnut
1 1/4" headless thread (this should mate with your camera's mount thread)
---
Tools:
Drill (I used a press, but its not necessary)
Vice (you might be able to work around this with clamps instead)
M10 Thread tap (for threading the holes in the slide to accept the bolts)
Angle grinder with cutting disk
Sandpaper
Tenon saw / Hacksaw (something fine enough to cut the acrylic)
Process:
First to bend the tubing into a sliding rail - I used a garden tap fitting as a template for the size, just clamped it into the vise and bent the tubing around it into a 'U' shape. The key detail here is to get the spacing of the legs of the 'U' to be about the same as the distance between the 'clamps' of the seat post clamp.
Drill a hole in the seat bracket on the 'front' side - this will be threaded for a small bolt to tighten the seat post against the rail.
Remove all the spokes and central gear from the wheel until you just have a circular rim. Then cut this in half with the angle grinder (using a cutting wheel), and cut one of the halves in half again.
Drill a 10mm hole close to one of the ends of the 'quarter' sections - this will be the primary mount, the others are for when you encounter situations where you need more range of movement.
Put the M10 thread through the hole, secure on both sides with a nut, then add another nut, and the piece of pipe, and secure the pipe with a final nut. This should give you a fairly securely attached threaded rod, with a piece of pipe on the end that you can now mount the seat bracket to.
Put the U shaped rail into the seat bracket, then put the bracket onto the pipe on the threaded rod. Secure everything with a spanner.
Finally, put the slide together by putting a washer on top, and then screwing an M10 in a short distance - it should not stick out the bottom.
You are now essentially done. If you happen to have a camera mounting plate that fits between the rails (as I did) then you can just slide that in, and away you go! However, if you want to make your own camera platform, it will give you a little more adjustment range.
If you are making the camera platform:
Cut two squares from the acrylic ~ 100mm side, and two strips ~100mm long and as wide as the internal diameter of the 'U' shape you have bent.
Drill a hole about 30mm from one end - this will take a small screw/bolt and nut that will keep it together.
Drill another hole about 30mm from the other end - this will take the 1/4" thread to mount the camera onto.
Put it all together - large squares at top and bottom, strips in the middle, and slide onto the U rail.
See the picture for the finished product. I think that will answer a lot of questions where my description is lacking!
Finally, I calibrated it by drawing the outline of a nearby fence on a window, using a chinagraph (grease?) pencil (I loosened the bracket bolts slightly to allow me up/down movements). This gave me the ability to easily calibrate it in two dimensions, although calibration was quite a mission...
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Forum: Photographic Technique
04-09-2010, 06:40 PM
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The inspiration for the final design struck me while I was playing with my first tripod modification. When trying to get the next level, I was adding bluetak to the back and the front of the mount - at the back to push the camera forward, and at the front to increase the elevation of the front of the camera. It got me to thinking that this problem could easily be solved with a 'ski jump' mount - one with a slight curve so that the nodal point would automatically stay in the correct position when moving the camera forward or back...
I had also seen the rather groovy looking circular flash mounts made by 'really right stuff'. So my mind was now set - I was going to use a circular 'ring' mount...
The key benefit of the curved track mount is that once the nodal point is at the center of curvature of the track, no movement of the mount will move it from that point in space. And with some careful thinking, all that is necessary to get the nodal point to the center of the circle is a single adjustable track, and a hinge for the track to rotate on.
So I had reduced the design to a single hinge point and an adjustable rail. Also, the joint of the rail to the track could be a right angle - good for stability.
So its onto the build!
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Forum: Photographic Technique
04-09-2010, 06:19 PM
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Hi edward,
You make an excellent point - most panoramic heads are based around an 'L' type bracket. And its true that it would be possible (in theory) to make a fairly simple 'fixed' arrangement that allows only a single camera/lens combination. However, there are a few problems in my particular case with that option:
1. There is virtually zero chance of me being precise enough in the build to create a fixed system that finally results in the nodal point being in the right place.
2. I would like to be able to use a few different lenses with it.
Both of these requirements lead to the design needing a means of adjustment. And since the usual 'three L bracket' method requires three adjustable parts, my mission was to see if some of them could be merged together.
The first usable idea was to have a 'ring' around the lens, and as long as the ring is at the nodal point, it would be fairly trivial to get any lens to rotate around this point. That would reduce the number of adjustable parts to zero! (see first picture)
But this proved impractical in my case - the problem is that my lenses are manual focus, and this would not allow me to focus the lens. My quick analysis of the nodal point of my 28mm lens put it just under the focusing ring. As a side note, this 'gyro' mounting (I thought it had a resemblance to a gyroscope) would allow the camera to easily be mounted in both portrait or landscape mode with nothing more than rotating the camera.
But I was back to trying to mount onto the 'tripod' mount of the camera...
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Forum: Photographic Technique
04-09-2010, 01:28 AM
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I'll have to spread this one over a few days - I can't seem to find the time to do a full write up all at once!
Phase 1: Early design and Requirements.
So I have been trying to take some panoramic shots lately - inspired in no small part by the panorama contest held recently, and some of the fantastic photos that were the result.
I found that one small modification to my $15 velbon CX449 tripod would allow me to take decent single row panoramas - it has a 'flip' type portrait mode, and by turning the mount around, so the camera mounts on the 'outside' of the stand the point of rotation was actually pretty close to the nodal point of the $20 28mm lens I was using.
But the building I was shooting really needed a two or three row panorama to get all the trees and such-like in. Also the aspect ratio was so extreme that in order to get a print a decent height, it would be as long as the wall in our flat!
So I thought about it for a long time, played around with bluetak and such like, and finally decided to check out a 'real' panorama head. A bit of googling, and I found that many people had build their own DIY pano heads - there is even a flickr group of DIY pano heads.
The problem here is that the idea of me getting all those angles right, and getting everything square and adjustable just didn't suit my style of construction (which tends from 'amateur' to 'gonzo'). So the quest was on - how to minimise the number of adjustable factors to the bare minimum (from three in the typical 'nodal ninja' type head to preferably one or two).
I got it down to one adjustable joint, and a single hinge - more detail to come... (feel free to comment on how you might do it!)
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Forum: General Talk
04-07-2010, 11:36 PM
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Well, reckon I've about the same chance of winning this one as any of the 'photographic' contests...
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Forum: Mini-Challenges, Games, and Photo Stories
04-06-2010, 03:58 AM
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More details to follow...
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Forum: Travel, Events, and Groups
03-17-2010, 04:05 AM
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So I would like to try my hand at a little project I have been thinking about for a couple weeks - a ~180 degree panorama of the college I live in...
Given the somewhat challenging angles I am looking at, my normal method of 'handhold and overlap by 50%+ probably won't work, so I'm wondering if there is anyone living in Melbourne who has a 'pro' setup for taking a pano who would be willing to share their time/equipment.
Thinking this Sunday (21st March) during the day (although the weather may not co-operate) or Saturday evening.
PM / Reply if you would like to meet a fellow Melbourne Pentaxian...
Frith
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Forum: Monthly Photo Contests
02-27-2010, 05:19 AM
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Taken recently, a family friend who came to visit brought her daughter. This is the result of a trip to the park, just before it rained.
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Forum: Digital Processing, Software, and Printing
12-08-2009, 05:56 PM
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Okay, so to complexify the issue a little more, what about Linux. I assume none of the software runs on linux, so from a purely hardware perspective, which of these would be best quality/cost choice for scanning 35mm negs for backup and prints?
Basically, I just want to get my negs into the digital world, from then I will be purely digital. So it would be almost a 'one off' use - but the lab here charges something like $50 a roll for scanning, so I figure my own scanner might be more cost effective...
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Forum: Digital Processing, Software, and Printing
12-08-2009, 05:53 PM
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Just as a slight detour, if you are interested in options, I use DNGConverter myself. I found it pretty easy to use, but it is likely not as feature rich as UFRaw.
Still, does the job for me.
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Forum: Photographic Industry and Professionals
09-25-2009, 03:26 AM
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well, it may seem a little insane, but it's really just an extension of a pretty common practice - a friend of mine sells adverts from old plays (circa 1960) on eBay - usually gets more than $10 for an original advert.
2008 is a bit recent, but in this day and age, how many here would be able to put their hands on the advert for the very camera they own? I sure couldn't (although abject poverty causing lack of magazine purchases for the last few years probably has more to do with this...)
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Forum: Photographic Technique
09-22-2009, 11:36 PM
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Hi RHN12,
Man, you could almost be my twin - Melbourne, K20D, looking for hard disk space...
Anyways, there are really two main issues you are contending with:
1. Download Space
2. Backup Space
Personally, I find the best way for me is to use the internal drive on my computer as the 'download space' - this has most of my photos, plus all the 'works in progress'. Then I use an external HDD for backup (500GB USB powered), but a *real* backup system (as already alluded to here) needs at least one, preferably two more options.
Prints are pretty much the ultimate in 'long-term' storage - archival prints will last for ages, especially if they are well cared for. You second option is to try the archival DVDs. The only brand I can suggest here is the best: Taiyo Yuden. They are a little more expensive than the others, but they are the only ones that I have found with *universal* good reviews. And they really aren't that expensive in the scheme of things (especially when you compare them to a new lens/accessory).
In Melbourne you can get them from Norts and Ones - they specialise in 'backuping'. There are cheaper places, but unless you know exactly what you want, you should try starting there.
The issue with RAID arrays is twofold: Management and Hardware. Firstly, since some of us only have laptops, RAID just isn't a possibility. Secondly, setting up and managing a RAID array is not for the faint hearted - and if you screw it up there is a real possibility of losing all the data. Unless you are a Real Man, then its probably not worth your while to invest all the time and energy into setting up a full NAS with RAID - not when you can just buy a network storage 'box' straight off the shelf, plug it in, and off you go.
But remember - in order for something to be considered 'backed up' it *must* have at least *three* physical copies, with at least one *offsite* (e.g. mum's place, grandma's, safety deposit box, bunker, etc.). And very few digital storage technologies will 'hold' for more than a few years - consider a complete replacement of all backed up data at least every 5 - 10 years.
Best of luck!
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Forum: Photographic Technique
09-22-2009, 06:09 PM
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Hmm.. Okay, that does make sense in a way - I mean, that image does look a bit miniature, and I can assume that all you did was blur the foreground and background.
The implication of this is that with super powerful lighting (to decrease aperture) and a steady enough subject (for shutter time) you could make a small object look 'real size'. Is that how 'model' shots in films look real then?
But yet... The person sitting next to me (who I said "What makes this image look like miniature people?") said that it doesn't look miniature to him - although when I showed him some other tilt-shift images he said they did look miniature.
So I thought of a little experiment. Which of these images are miniatures? Its probably pretty easy to pick, but in particular what is it about the first and last images that makes you answer a certain way?
Attachment 43704
Attachment 43705
Attachment 43706
Attachment 43707
P.S. these were shamelessly ripped from various places on the web and cropped. I hope this is okay with everyone... I'm just using them for educational purposes :)
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Forum: Photographic Technique
09-21-2009, 06:13 PM
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So this week on Make there is an article on 'making your own tilt-shift lens'
Build a Tilt-Shift Camera Lens for Peanuts | CreativePro.com
Now this looks like in interesting idea, but I have a different question: Why do the photos taken with a tilt-shift lens look like they are miniatures? I mean, I can guess that it is something to do with the change in perspective (e.g. parallel lines not converging as they normally would), but exactly *what* is it that the tilt does to the perspective? (I am not convinced its the shallow DOF that does it - otherwise portrait photography would also make the subject look miniature)
On a similar vein, if a tilt-shift lens can make a 'real' photo look miniature, then can it also be used to make a photograph of miniatures look 'real'? This seems to me to be an overlooked area of miniature photography - if its possible to bend the perspective this way, surely the models would look nicer 'blown up' to 'real' size.
Or is there some key detail I am missing here?
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Forum: Photographic Technique
09-21-2009, 06:05 PM
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I was lying in bed this morning, contemplating my next possible lens purchase (I don't think I qualify for LBA yet - I only have the two kit lenses from my MZ-50), and I got to thinking about choosing lenses and engagement rings.
Huh? Yeah, engagement rings. See (not so much now, but back in the day) the engagement ring would be bought by the proposing party (groom/bride on 29th of feb) and would present it to their victi*ahem* partner, without the partner ever seeing it.
We can assume that couples that were about to get married knew enough about each other that picking a ring their partner would like would be relatively easy (or at least, that's not the point of this post) - rather, the tricky part would be getting a ring size without giving the whole game away.
I've seen a few techniques to achieve this end, but my favourite one - having been burned once - is the 'rent the jeweller's sizing rings' option. This is one that I encountered and rather wish I had done once before - you contact a jeweller, they send you a huge keyring with a bunch of different sized rings, then you creatively use this to get the correct size and send them back with the size you want.
Also, you can buy the sizing set for a pretty small sum...
How does this relate to lenses? Well, one of the great things about the pentax mount is the availability of quality prime lenses, old and new, at a pretty nice price. The problem (which I am facing) is choosing the right one. Now, its easy enough to say 'this is good for portraiture, this is good for sports, this is good for landscapes', but I'm sure I would find many supporters here if I said that all the reviews in the world won't tell you if a lens will suit you or your style - especially if you are a beginner and looking for a first or second lens.
So an idea hit me - in this very forum I encountered the concept of the nifty travelling 50mm - a nice lens that is cheap enough that someone would 'donate' it to the cause of seeing a nice flikr stream. What if this idea were extended a little further?
There would be some issues to work out, but the concept is a 'travelling prime box' with a few different primes, perhaps not in the best shape optically (the ones that most people here would pass over or never use) that would nevertheless give someone a good chance answer questions like "Do I prefer the 35mm or the 50mm for portraits?" "Do I need the extra speed of a 1.4, or is a 2.0 fast enough for most of my work?" "Should I use a 28mm for landscapes, or stitch a few 50mm's together?"
So the box would have (for example):
28mm
35mm
50mm
85mm
100mm
200mm
and each person would get it for a little while (a week? a month?) and after this time, they will know which lens they should look at next - it will be the one they have used the most in that time (from most of the stuff I have read, most people have one lens that spends 40% - 80% of the time on their camera).
The lenses themselves needn't be especially good quality (scratches, fungus, etc) it would just be to get an idea of what length and speed you shoot best with. I guess this is the recycler in me - it seems that there must be a tonne of lenses out there that have fairly minor issues overall that are really worth next to nothing because perfect examples can still be found that aren't that expensive. This might be a way to get them some last useful life.
What do you think? We might need a separate 'box' for each continent (keep postage down), but I imagine there would be many people who would love the chance to try a bunch of primes seriously before making a risky purchase. Then again, this might be just another crazy idea that you get from too much procrastination and not enough study!
Frith.
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Forum: Site Suggestions and Help
06-03-2009, 06:21 PM
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Fair enough for finding information, but what about asking questions? I mean, there is a 'lens review' database, but also a section on 'duscussing lenses'. Isn't that because asking specific questions about particular projects/combinations is different to researching the various qualities of the lenses?
In a similar vein, the article section, great as it is, doesn't allow for posting questions like "What wavelength filters will results in maximum visual contrast?", or "What are the limits of the various sensors/film?".
I see your point that we already have a section for gathering information (articles), and we don't want to try to copy wikipedia, but this suggestion arose because I wanted to discuss the theoretical maximum aperture of a given body, and I couldn't decide which section to post in. Hence the idea of a 'physics/science of photography' section.
Although, questions like that might be rare anyway I guess...
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Forum: Troubleshooting and Beginner Help
06-03-2009, 06:33 AM
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f1.0 and f0.95 haven't been made for the pentax mount so far as I know. I heard this was related to the register distance (makes sense in a way...), but I want to know why? I'm interested in the theoretical limits (in this case...).
This would inform the price vs. benifits scenario (further from theoretical is easier), but what about mirror lenses? Cant they focus as much light as they want onto a focal plane?
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Forum: Photographic Technique
06-03-2009, 05:33 AM
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Heh, just thought I would throw my $0.02 in to the ring.
The idea of street photography is a bit scary to me - more due to a (probably irrational) fear of the reactions of the average pedestrian.
But it seems to me that this discussion is focused on an interesting semantic issue - that is, what is street photography.
On one side (which I'll define in shorthand as 'externalisers' - the image is of the surface) we have photographers who are taking pictures of a street, and there happen to be people on this street - it would hardly be an interesting street without some kind of life anyway, right?
On the other side (shortened to 'internalisers' - the image captures something of the inside of the people) we have those who think the shot is of people, and the street just happens to be there - I mean, a street by definition contains traffic, right?
So the essence of the discussion seems to be this dichotemy of street with people vs. people with street.
I can definitely understand the internalisers - if someone points a telephoto at me on a street it would make me somewhat uncomfortable. However, I personally love to shoot streetscapes - typically with a wider angle - and the thought of trying to talk to everyone in one of my shots leaves me a bit cold.
Even if we could all agree that photographing the street (with people) is okay, we would be left with the question "when is it a shot of the street, and when of a person/people?"
Love some other perspectives on this...
Frith
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Forum: Site Suggestions and Help
06-03-2009, 05:17 AM
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Okay, so I'm pretty new here, but it seems that there is a lot of intellectual discussion related to the limits of hardware, and there is quite a lot of knowledge related to the physical properties of photography.
E.g. the thread on actinic photography (related to manipulation specific light wavelengths).
The discussion on the possibility of an F1 50mm lens.
Threads regarding depth of field in macro photography.
Others, I can't recall off the top of my head...
So might it be useful to have a section related to the physical properties and limits of light/lenses/camera bodies. Answering such questions as "How does noise relate to ISO in terms of SNR?", or "What are the wavelengths of light the eye is most sensitive to?".
Just a thought...
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Forum: Troubleshooting and Beginner Help
06-03-2009, 05:05 AM
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So I'm a bit of a newbie to the 'technical' side of photography. I get the 'stops', shutter speed, ISO, and aperture part. I know what 'register' is, and how mirrored lenses avoid chromatic aberration. But I have a fairly simple question:
What creates the theoretical maximum aperture for a given camera?
In my head, aperture is related to the maximum amount of light a lens can admit, and (in theory at least) can't a lens be made to an arbitrary diameter with focusing optics 'bending' the light onto the film plane? Or is there some kind of physical restriction based on the 'cone' created by the register/mount diameter?
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Forum: Welcomes and Introductions
05-27-2009, 12:22 AM
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The question is, why take photographs?
I like to see something I have made, although the vast majority of my photos are 'snapshots'. I take a bit of pride in making the holiday portraits and nights with friends photos look nice.
I love a fast lens, a manual focus a big print and a lively discussion. I've seen a few forums and taken a few photos but I am still learning a lot about both those things!
Heading to the US for a holiday this year - looking forward to some interesting shots! Before that, looking for a DSLR to retire the MZ-50, and some good grades.
Looking forward to learning a bit from this place, taking some more photos and improving my eye.
Hope to see you guys online!
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Forum: Film Processing, Scanning, and Darkroom
05-26-2009, 11:09 PM
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So, would it be offtopic to ask what type of scanner is best? I have a boatload of colour and B&W film and negs that I would like to drag into the 21st century....
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