Just a pictutre or two

Daniel, love the 'fungi' pics. Sharp and subtle !!!


I was talking on another thread about buying 'cheap' stuff to give macro photography a try, and I stand by it. Go on, sellotape a toilet roll between your camera and your favourite lens !!! But be warned, as soon as you do, and you see the results that can be achieved, you will want more.
I got my bellows and 1/2 dozen extension tubes out over the weekend, and captured a bit of an onion. This set up is ok for kitchen-top macro photography, and I am pleased with the results, but I want a system for field use.








Pentax ist*DS, 100mm screw fit Takumar, 1/250 @ f22, bellows, 4 or 5 extension tubes, with FTZ500 fired through my white T-shirt


You seem to like the 105 Sigma, so could I ask you a couple of questions, ??
1. People say Sigma lenses "almost" work with Pentax cameras. Do you think the 105 would be ok with my DS ?

2. What is the magnification ratio with the lens, do you get 1:1 without tubes, ( or toilet rolls ).

3. There is also a 150mm Sigma macro, do you have any knowledge ? Good - Bad - Rumors ?

I hate to perpetuate the myth of Scots people being 'tight with money', but, you may notice in the picutre, I used a plug from the kids headphones and 2 x clothes-pegs as a remote release, but I would be willing to part with cash money for the Sigma 105 after seeing you pics.

on the subject of polarisers, I have a polariser, but don't know if it is linear or circular. Is there a way to test it?

Look through it into a mirror.

If it's linear it will look the same no matter which side you look through it.

If it's circular, one way it will look dark and if you flip it over it will look lighter.


Drew

I'll try the mirror trick.
What I did notice, is that my polariser gives the same effect as my polaroid sunglasses when pointed at a LCD display (which allso have a polarising filter in front). Turn the filter and the whole LCD goes black.

Hi Golf,

Glad you liked the pics - your onion looks fantastic (bet you never thought you'd hear that phrase ). At the moment I've got nine extension tubes knocking about (three sets), so perhaps I'll try something like that myself. Might have to use a 200mm lens though to keep the subject off the front element!

I too am happy to try anything cheap to get the effect I want, see my post here: https://www.pentaxuser.com/forum/viewtopic.php?p=15417&highlight=#15417. I've now replaced this with a Lumiquest Diffuser (http://www.7dayshop.com/catalog/product_info.php?cPath=777_1&products_id=100368), which I find just as effective, doesn't blow around in the wind, and looks a little more professional.

To answer your quesions:

1) My Sigma 105mm works perfectly with my D. Whether there would be any differences with the way the DS would communicate with it, I don't know, but I haven't heard of any problems. I'm sure someone else on here uses this combination.

2) You do get 1:1 magnification, but you can also use tubes too, to get greater ratios. The fly pic on the other thread was using a tube, and the image is full frame. As the lens has an aperture ring, you can use manual tubes with no problem. A lens that gives 1:1 is so much more convenient than any lens with tubes, as you never seem to have the right combination on for the composition you want.

3) I haven't tried the 150mm, but it's an EX lens (I find the build quality of these lenses superb, very solid), and I have no reason to think the quality would be any less than the 105. The 105 is more common though, and you may well be able to pick up a good value secondhand one. Mine was from Jessops a year ago, and cost me about £90.


Hope that helps,
Dan

On the subject of Sigma lenses "almost working" with Pentax bodies, I believe (and am prepared to stand corrected) that Sigma do not pay Pentax royalties for full information about how the bodies communicate with lenses, but reverse-engineer to gather that data. Therefore they may not be privvy to all the details of the lens-body communication. However It doesn't appear to have had any adverse effects on the way my 12-24mm 1:4.5-5.6DG EX and 70-300mm 1:4.5-5.6 APO DG perform, which is they communicate perfectly.

Cross your fingers that they'll still work with the K10D.

G

Galoot,

I hadn't thought of connecting all my macro pieces together to see what the result was. So I attached my Tamron 90mm Macro lens to a Pz-AF 2x Teleconverter to a vivitar 2x Macro focusing teleconverter to 12mm + 20mm + 36mm extention tubes and vivitar 6000 ring flash with the results:-







It only seems to work fully open at F2.8. Exposure 1/180, ISO 200. Field of view is 4mm on the longest side. No cropping. Just need to work out how I can support this monstrosity so I can focus properly. Anyway if it carries on raining it'll be a project for tomorrow.

Tim,

Are you sure the lens isn't stopping right down - I hate to tell you this, but I think your sensor needs a clean. The images have quite a few specks of dirt showing, and being this defined would suggest that you were using a small aperture - you probably wouldn't notice them at all at 'normal' ones. The very shallow depth of field is probably just due to the high magnification.

And I'd suggest a beanbag as a support.

You've inspired me, just off to round up my extension tube collection...

Dan

Dan,

Yes I spotted the dirt, but couldn't be a**ed to clone them out!

I tried taking pictures with the aperture manually set to diffent stops from F32 down to F2.8, and in this configuration (everything + kitchen sink) on the body the resulting image shows the same depth of field. There was one combination of not-quite-everything that allowed proper setting of the aperture. I should have kept notes - will just have to experiment again!

Try 'stacking' two lenses. A 50mm say, reversed onto the front of a 200'ish mm to give roughly 4X (200/50) magnification. A zoom lens will do for the 200mm.

Cheers,