Thursday, 24 April 2008

old cameras still work

Just spent a little time with my first roll of colour 120 film in my Bessa (listed elsewhere on this blog, just search for bessa). I can only say that it has passed with flying colours. The image below links to a rather bigger 3832 x 2628 pixel image (which is about 10 MPixels), Yet this is only from a 1200dpi scan of the film. For people used to working with 35mm, that minature format requires 2700 dpi (and preferably 4000 dpi) to get substantial images. Scanning this at even 2400 dpi would give 7864 x 5256 or 41 megapixels.


Dang it all, blogspot resizes it to 1600! Oh well...





Now, this is a 1950's camera. It has no mod cons of any type (no metering, no focus assist, primitive film advance).

Used right, this goes close to giving the sort of detail that you can get with a 1Ds MkIII. Certainly its not as fast to use, or have any features that would make it popular to people photographing Wimbledon or Pro golf, but for an amateur photographer who has a 5 or 6 megapixel compact digital and is seeking better 'landscape' images ... well look seriously at a 6x9 film camera!

I personally like the the Bessa as its a folder, meaning it folds down to a little bit smaller than a video cassette and slips into a side pocket of my backpack. For those who don't feel like an old folder like this you should seriously consider a Fuji GS690 as these are superior optically and have range finders (for focusing the camera).

Size maters (for film that is ;-)

I thought I'd put a few more samples from my flickr account

forest floor

and a detail segment

center segment

click here for full size

notice how the tree I chose for focus stands out? This short depth of field can be an asset that you just don't get with smaller formats (like 35mm or digital).

Wednesday, 23 April 2008

bog footy

Here in Finland there aren't too many flat places which aren't rocky, and those that are are often swamps. So just where do you go to to play footy in summer? Well, the sign points the way :-)



Yep, that right, the bog



Now, it might look just like a grassy field in that picture up there, but this is a full on peat bog, and you'll sink to your ankles even stepping onto the tufts of grass out here where its 'un-trodden' ground. Walk with caution and better still, bring the gum boots!

I've found that there's a reason that everyone here likes to wear gore-tex boots!

As you can see even though I'm treading carefully, there's water oozing out of the ground around my foot, and a puddle already waiting there on the left.

These wetlands are very rich, moist environments by the way, generating heaps of biomass and helping to keep the water pure (well, where they don't get churned up by fellas runnin around in in em that is).

You can see from the field though that there isn't much 'untrodden' moss over there.

Just in case you happen to think that's a dry looking field over there, I took this from the back line.

That' ain't grass there laddy.

There was (sadly) noone there on the day we were there, so I didn't get to see a match, but heck, these fellas must be fit as if you started running in this place you'd just sink deeper.

I started to sink in one place, and found that you just can't push down with the other foot to pull the stuck one out or it just pulls you in deeper.

Its all good clean muck though, so its not hard to get off your jeans later on.

Say, if you've ever been to a wetland in summer, you might have noticed the mosquitoes?

That'd keep you running ;-)

Monday, 21 April 2008

humidity and cameras

Most people don't realise that Fungus grows on camera lenses. For example this page explains this a little. Fungus attacks camera lenses in storage, and its growth is related to humidity. So people who are a little more in the know often speak of removing humidity with Silica Gel. I've found this is not a sound practice for anything longer term than a few weeks. Given the regularity of this discussion I thought I'd put a blog entry here about it.

Background

If it remains below 50% then fungal spores will not germinate (as far as I've read). Keeping it below 30% risks dammage to your camera as the lubricants and foams will start to 'dry' ... yes, even salt crystals have water in their stucture and you can get anhydrous salt powder.

I lived in a semi tropical area, I had already lost a lens to fungus (a 50mm Zukio macro) from my Olympus from fungus (I often visit rainforest in the rain). I had started a business and bought some lenses worth quite some thousands of dollars (IE: TS-E 24, 90, and some large format lenses). I thought it prudent to conduct investigations.

I have a friend in the army who is a munitions specialist and he has reported to me that for their purposes silica gel was insufficient to maintain correct humidity. So wondering what this translated to in a quantitative manner I did the following experiment (if you google this on google groups this you'll find the results published back in the late 2000 on rec.photo):

Humidity Experiment with Silica Gel

Materials
  • ~20g/100cc of Purple indicating silica gel
  • heavy duty "zip seal" plastic bag (1 liter capacity)
  • glass vegemite jar
  • electronic hygrometer

Method

I thought I would test using a common zip seal bag, since cameras are often placed in these for protection. Since the camera in the bag occupies some space in the bag (and prevent the bag from being slim or vacuum sealed (if they indeed can be), I placed my sample of silica gel into a (lidless) glass jar with an electronic hygrometer hopefully replicating storing a 35mm camera lens in the bag.

The bag was only containing air from the room, no other gases were placed into the bag (such as gas from cylinder of nitrogen).

The bag was then zip sealed. The jar was put on its side, so that the top was not blocked further by the plastic and the hygrometer was visible with out disturbing the setup for making observations.

Note: The hygrometer displays LL% when out of range at the low end of humidity (which was cited as ~30%RH by the maker) and HH% when over 90%.
raw data

23-Mar-00 68% 6:38:00 PM experiment started
23-Mar-00 41% 8:52 PM
24-Mar-00 LL % {very rapid absorption depletion of humidity in bat}
25-Mar-00 LL% {already seems to be loosing the colour in the crystals, some are pink]
26-Mar-00 LL% {more of the crystals seem to be pale pink}
27-Mar-00 LL% {more of the crystals seem to be pale}
29-Mar-00 32% {most of the crystals are pink}
31-Mar-00 39% {more seem pale, a few are still dark}
02-Apr-00 43% {no apparent change in the crystals}
03-Apr-00 45%
04-Apr-00 45%
05-Apr-00 48%
06-Apr-00 50%
09-Apr-00 52%
10-Apr-00 52%
11-Apr-00 54%
13-Apr-00 57% {almost all crystals are depleted, about 9 remain as pale purple}
15-Apr-00 60%
17-Apr-00 64%
18-Apr-00 66%
24-Apr-00 64%
27-Apr-00 73%
29-Apr-00 76%
experiment concluded duration = 22 days.

graphically:


Figure 1: humidity measurements

Conslusion

As you can see, even in a small zip sealed bag the humidity rose to a point where the silica gel was failing to cope with humidity migration across the membrane of the plastic, and simply maintaining a constant level in the bags environment. Since silica gel can also release the humidity it then becomes a 'buffer' keeping the humidity reasonably constant (perfect for those fungii and molds) when the outside ambient humidity goes high. Typically this goes high in the night (as the air cools) and low in the day (as the air heats up).

Storing stuff inside your house (often cooler than outside) in a tropical area will ensure a nice humid atmosphere for your fungi. Meaning camera bags placed in cupboards are the worst locations.

Based on this I constructed my own humidity cabinet from a peliter effect device (commonly used in electric 'car fridge' systems) to condense the air and drain it out of the cabinet.


My power supply is a $15 cheapie 8 amp 12V car battery charger and a $20 12V GEL cell (to even it all out). I then ran a simple 24 hour timer circuit (like used to turn lamps on and off) to shut off the entire thing at different times of the day (used a relay to kick in on the 12V side of the car battery charger to shut off the power from battery to Peltier too). I made the back wall of the cabinet 5mm ply and cut out a shape to take the peltier in the middle. This puts one side of the heat sink inside (that'll be the cold side) and the other outside.

You'll need to fiddle with heat sinks to get the right efficiency, but I settled on this pair:
inside and outside

Then I made a simple catch tray (for the drips) out of a cut down plastic milk container and ran a bit of aquarium pipe out of the cabinet to drain it. Careful with this as in my summers I get about 500ml a day on a good humid day!

Naturally you need to be a bit handy, and have some electronics knowledge too. Of course you could buy one of the pre made ones.

hope this helps

little critters

I just got the call "hey, there's a hedgehog down here! Come as quick as you can"

He was crunched into a little ball of spikes, and didn't want to move. So after Anita went to work, I popped back upstairs and put my lens onto my camera. I didn't know if it'd still be there when I got down, but and got down there to find it still wandering around; although further up the hedge (who'd have thought).

click for larger

It froze as soon as I got there, but after I sat down it was quickly on the move again. So I grabbed a few 'hurried escape shots' ..

click for larger

and waited around. Sure enough someone else came back down, but headed over towards where he was and sortof 'flushed him out' towards me.
click for larger

"yes, its looking clearer ..."

click for larger

So with a sniffing of the air it seems it was going to head my way. But after I took this shot it seems that it didn't like the sound of the shutter on the camera and turned around again.

So I thought I'd let it have breakfast undisturbed and headed back up here for a coffee and to publish this.

Thursday, 17 April 2008

size matters (what film looks like)

I was just talking with a friend who wasn't sure of the differences in size between 120 roll film and 35mm. It occured to me that fewer and fewer people seem to know just what a negative or a slide is any more. Today in the digital age people seem to not know what film even is.

So, I thought I'd put a comparison of the basic formats up here. Most people still know 35mm film (you can still find it at the supermarket), but good old box brownie 120 film seems to be forgotten. To rectify that here is an image below with a strip of 35mm and 120 side by side on the glass of my flat bed scanner.




the 120 film is much wider, allowing the camera to 'record' a bigger image on it. These images are from a 6x9 camera (meaning its supposed to be 6cm X 9cm in size). Actually they're from my nearly antique Voigtlander Bessa camera. If you click on the image, you'll notice that there are frame numbers along the bottom of the 120 film too. These are actually printed on the film at manufacture, and are only guides for using other formats (like the much smaller 6 x 4.5cm)

I like 6x9 the most because as you can see you get a much bigger film area than 35mm recorded onto the film.

This essentially means that you don't need to 'enlarge' or (magnify) the image as much when making a print.

This means that if you're making a typical small print of 10x13 cm the negative of the 6x9 camera really only needs to be made a little bigger, while the 24x36mm image needs to be nearly 4 times wider.

Now, if your lens is less than perfect this will mean your pictures will be less than clear.

Remember all those blury awful 35mm pictures from the 70's? Its interesting that the pictures taken back in the 50's (or even in the 1900's) are often sharper. Well its all down to the size of the negative. So, you see size maters!

Certainly newer cameras are improving, and the latest in multi thousand dollar camera and lens will make very sharp pictures indeed. Even better yet, digital SLR cameras make the best possible use out of that good lens and allow very good prints. But after you've spend thousands of dollars its still only just as good as an old 1950's 6x9 camera.

Click on this image to see a bigger version, its been sized down for the web, to just 1600 x 1012. However the original size is 5799 x 3667 and that's 21.26 MPixels.



Look around the image, but keep in mind, this is from a less than $200 camera :-) See if you can do better with a more expensive one ;-)

enjoy

rear window

I was walking through Lappeenranta the other day and came across this American car. It had Rambler written on the front grill, so I'm not entirely sure who made it.

Anyway, the owner (clearly some kind of fan of American cars to own one here in Finland) seems to have been having some problems with reliability.

Well at least that's how I read the rear window sticker

:-)

Tuesday, 15 April 2008

Bessa useful lens limits

To add a little more to flesh out this camera to a potential buyer (for using not for those who simply collect), I thought I'd explain that this camera will simply not give sharp images from edge to edge at less than f11.

There is debate about the Vaskar lens on the camera, and while some say that the lens isn't sharp other swear that it is. Here I'll say that it can be and that it depends on the photographers choices.

Here's why.

For large format camera users looking at the film plane with ground glass is a normal and even essential thing to do. Large format cameras even have the corners cut off on the ground glass, making it easier to actually do this.

The reason you'd want to look here is to see if you've moved your lens too far, and run out of the area where the image from the lens actually falls (you see, large format cameras move the lens around to give control over focus and perspective see this explanation). So I popped open the back of the Bessa early on in the piece to see what I can see. I've done it again here to explain my assertion above.

In this image, I've taped a bit of translucent (foggy) plastic sheet to allow you to see the image formed by the lens, and the lens through the corner of the frame.



You can just see the lens through the torn off corner of the palastic and you can see its not quite perfectly round. Looking at the image below, taken at f4.5, you can see that the shape made by lens is not perfectly round. This will mean that less light will fall on the edges of the film than in the middle. This will make the image darker at the edges (vignetting) and will also reduce the image quality too.



This image is taken at f8 and you can just see that the the lens is still slightly obscured in the bottom third at the left.


its not until you get to f11 that the lens circle is now nice and round


So basically this means that the lens needs to be stopped down to about f11 or lower if you want edge to edge uniform lighting, or even edge to edge sharpness. You'll notice we're not right at the corner of the film plane here, so to be on the safe side stopping down a little more is needed. In practice I've found that you need to stop down at least f16. So, essentially this means that this is a "sunny 16" kind of camera or use a stable support (Eg tripod or solid base) and then use f16 (preferably smaller) and 1 second or longer so you can get reasonably accurate exposures.

Further, there is no accurate markers in setting the aperture (no dent to feel the position of the aperture setting as in more modern cameras) and no 1/2 or /1/3 stop markers. Meaning you've got to 'guess' the adjustment and being more accurate than full f-stop is challenging (meaning that trying to set 1/2 or 1/3 stops is guess work). This is ok with black and white, and possibly colour negative, but I think it makes a challenge for slide or 'positive' film.

However, if you can set it at f16 or f22 (and use a tripod) it gives very nice results. Like this close focus example at f11:


You can see (if you click on the image) that the edges are starting to fuzz ... this was exposed at f11. Below is and a segment from the center of the negative. Please click on either to see larger versions.


So, if you can put up with the difficulties of using this camera:
  • limited useful f-stop range
  • single focal length
  • no light meter
  • focus by number (needing some way to correctly pick the distance)
  • no 'dent' to be reliably sure of f-stop selected
  • no partial f-stop marks
then it can provide you with excellent images.

Monday, 14 April 2008

Bessa testing part 2

To further answer my questions about the usefulness of my Bessa 6x9 camera I took another couple of images and compared them to the theoretical 5D (actually my 10D with a similar angle of view lens to what the Bessa actually sees).

The image at left was taken today with some slight sleet happening (to obscure the distance) and generally dreadful dull lighting conditions.

I've scanned the film on my Epson scanner and presented the results here.

Firstly lets have an overview of the image taken with the 10D.


As you can see it represents a much smaller segment, and the target area is not in direct sunlight (making the overall contrast similar to what I took with the Bessa above).

S0, lets get to the details:


This (above)is a 100% crop of the image taken from the 10D, while the image below is a 100% crop taken from a 2400dpi scan from the film (ADOX CHM 120 roll). Exposure was 1/10th of a second at f8


Please click on this to see the full detail (as this is sized down by the blogger software, you can even see some of the snow fall in better detail).

Quite stunning if you ask me, but I'll leave you to make your own conclusions.

From the same roll (but no digitals taken for comparison) is this image. I took this propped on a log lying around (no tripod) for support at 1/25th of a second @ f22.


Please click on it for a larger preview. I've then taken a 100% crop from a 2400dpi scan of one of the logs poking out of the stack there. Again this is resized by blogger, so please click on it for a the full 100% view.


Amazing stuff. Using this camera it is important to keep the aperture small. Even though this lens is rated to open up to f4.5 it is nowhere near good at the edges at this. I consider that f16 is the maximum working aperture for clear images (and f22 its best).

So I am now comfortable that the combination of my 10D and the Bessa for images on my trips will give me the combination of versatility and ease (the 10D) and high quality images if I so desire or need (the Bessa).

Wednesday, 9 April 2008

Testing the 6x9 - Bessa vs DSLR

I've been very keen to see if my new 6x9 folder will make an effective backup to my large format camera, and if its close to my Canon 10D DSLR.

Timing of arrival of the camera coincided with running out chemistry. I've finally got some developer but not any 120 film, so I decided to shove a sheet of cut down 4x5 ADOX into the camera and see what I see. I goofed on the first cut of the sheet, so the second 'slice' needed to go in at an angle to ensure the plate held it firmly. This is the over all view of the 'test shoot'.




The 'angle of view' is very slightly wide, more or less its 'standard' (the lens is a 105mm which on 6x9 gives 44° which is about the same as a 45mm lens on a 35mm camera).


This is an image taken with my 10D with an EF24 f2.8 which as you can see is a little wider. I should point out at this time is 'effectively' a 38mm due to the APS sized sensor recording only a segment of the image.

You can see the extra width here to the right of the chest of drawers, basically the ironing board is in the scene.

To get the image from film I've used an older Epson 3200 scanner. If you don't know them, they are not the hottest item on the shelf, and are regarded by many (including me) as running into their limits at about 1200 or 1800 dpi.

Well, to see as much as I could potentially see, I've scanned the film at 2400 dpi but then down sampled to 1200 for presentation here.

Anyway this is the image that I got from the film:



Quite surprising, certainly a little soft looking, but still one can see the marks on the ruler. The ruler in the picture is (as can bee seen) 1:75, which means that 1 full graduation ~= 1.25cm

The smallest marks are less than 1mm apart, but these aren't quite distinguishable. The next largest markers represent just over 1mm and are distinguishable.

However looking at the image closely , something doesn't quite look right.

Here is a segment from the original 2400 dpi scan. It seems to be showing signs of motion blur when you look carefully at the graduations on the ruler.

Since the camera did not mount securely to the tripod and the exposure time is 8 seconds its entirely possible that I introduced some vibration in the picture!

If so then this image could be significantly shaper than it is, perhaps nearly as sharp as that from my 'hypothetical full frame' image presented later.

Anyway, moving on, next is the 100% segment from the 10D using the EF24. You'll notice that the match box is oriented differently. I only thought of comparing to the 10D AFTER I had taken and developed this shot. (Dumb I know)



Not quite as large and certainly not as sharp. Yet this image was taken with the lens set to f11, I used a Manfrotto 190B tripod, cable release and mirror lockup using RAW (so no in-camera artifacts are working here to lessen the image potential). So its unlikely one would get a sharper image from the camera.

So for me this indicates that the trusty old Bessa is able to produce an image that can compete with that from a modern DSLR in terms of outright quality if nothing else. Not bad for a 50 year old technology.

The next question that comes to mind is, how would it stack up against a full frame DSLR? Well, I don't have one, but I do have a 50mm lens :-) While a 5D is not quite the same pixel dimensions as the 10D (so the density of recording for a given area is not as 'high' as the 10D) it is close! So, by putting my EF50 f1.8 onto the 10D I can take a segment from this to 'simulate' a hypothetical full frame camera with nearly the same angle of view as the 6x9 folder.

Taking the shot again (not moving anything this time ;-) I can get to see what a full frame digital would probably give in this segment.

Here is that image:



Definitely this is cleaner than what I was able to get from the Bessa and Epson 3200 and completely resolves the ruler,with the 1/2 graduations now clearly distinguishable (click on the image to see the full detail). The better depth of focus (and perhaps focus itself) shows the ruler to be clear.

Stop press

A friend of mine (who actually has a 5D and an EF50mm lens) has taken a picture of a similar ruler at 130cm just as in my test (with slightly different lighting).

This at left is a segment of that image.

So no doubt about it, actual 5D looks remarkably like that of my theoretical 5d (that is a 10D with the same lens mounted just therefore capturing less view) and very very sharp indeed.

So at $2500 will out perform a $100 1950's Voigtlander Bessa with a Vaskar lens in image clarity.

Hmmm ... I would love to see how a Fuji GW690 would do.

What does this mean?

So for me at this point I'm happy with my purchase. I am comfortable that by using my 10D for most of my trip photograpy and using the Bessa for a 4x5 replacement that I can get a good combination of lower costs and higher quality images. I can't justify the money for a 5D at this point, as well I'm sure that the digital cameras will improve (we've all been waiting for a 5D replacement for some years now). With film at about $3 a roll, and developing around the same I'm sure this will 'get me by' for at least another 2 years. Perhaps then a full frame DSLR will be affordable for me.

Lastly, I am sure that taking 2 or 3 images with the Bessa and stitching them together will give me results as good as my 4x5 :-)

Tuesday, 8 April 2008

Close up with 4x5

As surprising as it may seem I have not yet done any close up work with my large format camera. Perhaps all the 'bellows factor' calculation has put me off at a subconscious level.

Well, I had some fresh flowers handy last weekend, and thought "why not".

So with the digital camera as a light meter and Bob Wheelers VadeMecum as my guide for correcting for bellows factor I took this image.

I used my 90mm lens and the image is nearly 1:1 (meaning that 1cm of flower will appear as 1cm of negative). I am really quite surprised how well the 90mm (a wide angle) performs in close up. Not only is the angle of view better than what I get using a smaller format (such as the digital) but the depth of field is good too. All in all its come up rather well I think.

As well as the wonderful tonality seen here, there was significant detail available from the image too.

I thought I'd include a segment of a scan from the film done at only 600 dpi (click it to see that sized on your screen properly) to give you an idea what's visible in the image. I've inspected the negative at x10 and found that its quite sharp, probably supporting scans at 3000 dpi. Sadly my scanner runs out of grunt at about 1800dpi so I'd need to pay for that ;-)



This would allow you to make a print about 1.2 m high if one wanted to print something as big as that! You can click on either of these images to see them a little bigger :-)

Tuesday, 1 April 2008

Experiments in 6x9 cameras

Today I got my latest addition to my image making tool set. Its a Voigtlander Bessa I.

For those who aren't familiar with it, this is a 120 roll film camera, which is essentially the same paper backed roll film from the good old box brownie (minor changes).

This film is still popular with professionals today, and has been in use for since around 1900. Unlike 35mm (more or less killed off or at least badly wounded) by digital the larger image area provided by this film means that you can comfortably get 12Megapixels from even a modest flat bed scanner, or as much as 26 Megapixels from higher quality film scanners (like the Nikon LS 9000).

Of course its the lens which makes the image, and while all the other bits of the camera help as well you just can't get a good image with a crappy lens or poor focus.

The lens on mine is the Vaskar, which I'm told is no "killer".



However looking at the image on a ground glass (pressed against the film rails) seems to show images that are quite sharp (as long as you have them in focus that is) but a quite narrow DoF.

This last point (focus) is where this camera suffers in use. Focus is by adjusting the lens with nothing more than some markers on it for predicting the distance.

You can see the distance scale on the black ring around the lens (white numbers), as well as the black arrow just visible over there on the left side.

With no way to preview or confirm your focus this is all you have. I've checked it by making a bit of ground glass and putting it on the film area at back of the camera, and its not very accurate. But what you can see is that when its focused, its quite sharp. Nearly as sharp as anything else in my camera outfit (which includes 90 and 180mm Fujinon large format lenses, as well as Canon EF series lenses).

Worse the depth of field focusing guides (black on the chrome) suggest that when focused on infinity that things as close as 20 feet (6 meters) will be in focus too. Sadly this is quite optimistic, and I'm sure lends to the reasons why these older cameras were dismissed as being rubbish by a generation.

The shutter is a bit sticky on the example I have, so I'm not confident that it will operate consistently at shutter speeds of longer than 1/10th of a second. However, for daylight use I think this will be fine.

Anyway, no pictures yet as I've got no developer at home just now, but watch this space for some soon :-)