PHOTOGRAPHIC THREADS: camera queries, any photo tech stuff!

[Maggi Young]

The one Ian has a print out of the specs. for is the AnMo Dinolite AM413T USB Digital Microscope ... try this link:
  http://www.absolute-data-services.co.uk/dinolite_am413t.htm
 or this to see others
http://www.absolute-data-services.co.uk/dino-lite_usb_digital_microscopes.htm

[ChrisB]

wow, big difference in price eh?  Wonder why?  it still says magnifying 200x and looks pretty much the same as the one in the radio times picture, but there must be a difference for 10x the price... will be interesting to watch developments of this.

[gote]

The small pocket size digital cameras have so small inlet apertures that they can capture the image in any normal microscope or telescope.
I have made a simple device that allows me to place the camera on the top of the microscope where it lies steady during the exposure.
The BIG problem is that any microscope has a depth of field that is negligible and that there is no way to control the aperture. Even at the lowest magnification, the top and bottom of an Allium seed will not be sharp at the same time.
Magnification means of course that something becomes bigger and when we talk about telescopes it is easy to define. The picture through the telescope looks X times bigger than without the telescope.
When we identify magnification of a microscope we mean that the picture seen through the microscope looks X times bigger than the same object when looking at a distance of 25cm.
However, a device as those described here has no defined magnification. Larger than what??? The only reasonable definition would be that the picture on the sensor is X times bigger than the object photographed. The problem lies in that it is not really a microscope but a close up camera. Any old-fashioned bellows view camera is able to take pictures where the picture on the negative is many times larger than the object but then we can also enlarge the negative Thus the device has no well defined magnification.
Before buying a device that costs 250 quid, one needs to think it over. As I said at the beginning, the depth of field is the big obstacle. If we want to have a large picture of a small object we will find that the depth of field is limiting the usefulness. A good microscope has a diaphragm that can close the aperture when it is used in a transmitted light situation. However, if we close the diaphragm in order to increase depth of field, we get diffraction so the picture becomes less sharp.
In my opinion, the best way to define what we want in close up photography is to define the picture frame on the object. If we want a 1cm wide flower to fill the picture we need a device that makes one cm fill the frame in the camera. Suppose we have a 35mm system camera with a bellows extension. This means that the distance between the lens and the film plane shall be 2.4 times the distance between the lens and the flower. This is irrespectively of whether we have a standard 50mm lens or a 200mm telephoto.
The easy way for someone who wants to take close-up pictures with a simple digital camera is to use a pocket lens. Get a lens of 5-10 dioptries = focal length 20-10 cm. Fix the lens to the camera lens (sticky tape will probably do) Put the object slightly closer to the lens than the focal length of the lens. Use the zoom to get the right frame and shoot. In most cases you will need a tripod or some other device to keep the contraption steady.
The high figures of magnification are tempting but to the average “flower photographer” they are useless. I have found that when I put a small camera on a dissecting microscope, I get the best results with 10x magnification and medium telephoto setting on the zoom. (Photographing seeds)
I am unsure whether I have expressed myself clearly but I am happy to answer any questions (next week).
Cheers
Göte.         
   
   

[gote]

Why is it that some that are suitable are in the price range £12 to £15 and others cost £25 to £30? These were on the Tesco rack and the information given seemed to be identical. Is there any benefit in paying the higher price?

Contrary to what is said, there is NO true reliable back-up medium. The best thing to do is store important pictures at different locations and on different media. How reliable a CD is for instance depends on the brand of the CD and the brand of the writer used to back-up. A picture backed-up with a Plextor writer on Imation will last a lot longer than on a Tesco CD written with an el cheapo CD writer. ANY media degrades over time. A CD/DVD consists of a metallic layer and a polymer outside. This polymer is just a form of plastic and plastic degrades through enviromental influences. So CD's can also become unreadable. The quality of the polymer and the accuracy of the writer that burned the "holes" in the metallic layer of the CD determines the duration of the backup on CD. Harddrives are based on magnetism, that also degrades over time. And every time data is written to or from a memory chip these read/write actions degrade the chip too.

The only long term way to save data is to copy them to a new medium before the old medium has degraded. (and do this repeatedly) If the medium is a hard disk, this is not a big deal to do. Even if it takes a full day or two it can be done without constant supervision. If it is on CDs memory cards or (horror) diskettes the operation is very labourious. Presently a separate hard disk, only used as backup and stored in a safe place (vault) seems the most cost effective way but even that one needs to be rewritten at regular intervals.
Would you agree Pascal?
Cheers
Göte


 

[Pascal B]

I prefer hard disks too. Easiest to work with  and cheapest per GB. If the hardrives are in raid it is even better. But I have to admit I also mis-use the network storage at work for this, one of the advantages of working in IT....

[mark smyth]

The Canon all singing IXUS 200 IS - my next camera if/when I have the money - is down £50 to £200 on Amazon 
http://www.amazon.co.uk/gp/product/B002LSI1K0/ref=s9_wishf_gw_t?ie=UTF8&coliid=IQLYFYK5PMW6Q&colid=2CT51NM83R93S&pf_rd_m=A3P5ROKL5A1OLE&pf_rd_s=right-3&pf_rd_r=1S4EA4QX5YKQG84XRE9G&pf_rd_t=101&pf_rd_p=469296553&pf_rd_i=468294

[Gail]

The Canon all singing IXUS 200 IS - my next camera if/when I have the money

Do you know how it is at macros Mark?

[mark smyth]

yes, about 2 cm

[Martin Baxendale]

Any suggestions for an inexpensive and easy-to-use digital SLR camera? Any particular bargains anyone has seen recently? Looking mainly for something for plant photography, so good close-up, but also for general use.

[TC]

Martin, I'm afraid you will have to define a price bracket before any useful advice can be given

[Martin Baxendale]

I wasn't giving a price bracket, hoping to see just how low-priced but still good it's possible to go, but I take the point. I was thinking under £500, which I know is a bit limiting. I was really just wondering if anyone had seen any really good bargains around. But not to worry, I can do a bit of hunting around the usual outlets.

[TC]

Look at Park Cameras website.  They are showing the new Nikon D3100 +18-55 VR lens for £419.99.  The specification on this camera is higher than the D300s which sells at over double the price.
The CANON EOS 1000D with 18-55 IS lens is £369.95 in Jessops.
The CANON EOS 1100D with 18-55 IS lens is £459.95 in Jessops.  This has a higher spec. but you are also paying for HD video
You cannot really go wrong buying into Nikon/Canon as the are highly reliable and well made.  A 10 Megapixel sensor is more than adequate for normal use and will give you good quality pictures.

[Martin Baxendale]

Thanks Tom. I'll take a look at those. I was thinking about looking at Canons. The compact digital Canon I've had for a few years now has been very good for what it is.

[John85]

Some advice please.At the moment I use a friend's Nikon D 3000 to learn to use digital and I am very disappointed with the "reds" that are not "true".Even the violets become blue.Yet some red colors are right(like a tomato).The D 3000 is basic but do you have the same problems if you go higher up in the range and what model should you advice.I'd like not to have to use photoshop too often.
About the price:I don't have to buy the lens so I can spend a bit more on the digital stuff but please nothing too expensive.

[ranunculus]

Hi John,
I too use a Nikon, the D80, and must say that I have few problems with reds, oranges or violets. Bright yellows are always difficult, especially at shows, but this is not so much a colour problem but more a simple exposure issue. 
An image taken at Disneyland, Paris over the Easter weekend ...