All Forum Comments
Comment by petrochemist posted on World Photography Organisation Awards at 07/02/2013 - 10:14
Defragged wrote:
That's alright Dave.
As it happens I've got the SMC Pentax-A 100mm f4 macro, the Viv Series 1 105mm f2.4 and Cosina 100mm AF f3.5 often affectionately referred to by some as the 'yogurt cup' or 'plastic fantastic' because of it's flimsy build.
The point I wanted to make however is, the latter of the three I mentioned can usually be had for the least outlay and comes in various guises: Vivitar, Cosina, Phoenix, Exakta & Voigtlander and IMHO they are superb value for the money.
The Cosina is indeed excellent value for money, mine (the MF version) only cost £50, but as is often the case came without the matching adapter so only reaches 1:2 rather than the full 1:1.That's alright Dave.
As it happens I've got the SMC Pentax-A 100mm f4 macro, the Viv Series 1 105mm f2.4 and Cosina 100mm AF f3.5 often affectionately referred to by some as the 'yogurt cup' or 'plastic fantastic' because of it's flimsy build.
The point I wanted to make however is, the latter of the three I mentioned can usually be had for the least outlay and comes in various guises: Vivitar, Cosina, Phoenix, Exakta & Voigtlander and IMHO they are superb value for the money.
Comment by petrochemist posted on WTB: Cheap Macro lens at 06/02/2013 - 09:41
PM sent
Comment by petrochemist posted on FREEBIES: FILTER POUCH at 05/02/2013 - 15:27
Algernon wrote:
Thanks Stefan, the whole business of lens testing is far too complex for people like us who just want to see if a 300mm A* is sharper than a 300 FA*, that's why I only photograph a £10 note and take at least 4 shots at each aperture and pick out the best, (because of focusing difficulties). I might start using Live View for focusing. See this site for why?
Algi as MrCynical pointed out Photographing british banknotes is illegal without permission (not too difficult to get - but it expires after a year) Your much better off using Euros - the European bank has a list of conditions on it's website, if you stick within them you have permission.Thanks Stefan, the whole business of lens testing is far too complex for people like us who just want to see if a 300mm A* is sharper than a 300 FA*, that's why I only photograph a £10 note and take at least 4 shots at each aperture and pick out the best, (because of focusing difficulties). I might start using Live View for focusing. See this site for why?
IIRC as long as you're not photographing the whole note, and don't put high resolution shots on line you should be OK.
Comment by petrochemist posted on Lens Test Charts at 30/01/2013 - 10:24
Mike-P wrote:
Personally I would class Alan's picture as low light but it looks like the camera has front focused quite a bit judging from the snow in front of the fox (focus seems to be around the foot prints area).
Agreed, I was referring to the pub shot, and the headlights. The fox is certainly low light. I should have checked back through the thread and been more specific.Personally I would class Alan's picture as low light but it looks like the camera has front focused quite a bit judging from the snow in front of the fox (focus seems to be around the foot prints area).
Comment by petrochemist posted on How low is low light? at 26/01/2013 - 13:28
screwdriver wrote:
Light in both directions will diminish as it spreads to cover more area. sportyman531 wrote:
It looks bright in the darkness but it's designed to illuminate the pub sign, I'm across the road on the car park, the strength of the light diminishes by 4x the distance from the camera. If the camera will focus under these conditions it will focus on a station platform or in a railway yard.
Camera to subject light doesn't diminish, only light from the light source to the subject diminishes with distance.It looks bright in the darkness but it's designed to illuminate the pub sign, I'm across the road on the car park, the strength of the light diminishes by 4x the distance from the camera. If the camera will focus under these conditions it will focus on a station platform or in a railway yard.
It's not proportional to 4x the distance but to the inverse square of the distance - doubling the distance gives 1/4 the light, three times the distance is 1/9, ten times the distance only 1% of the light.
However the lights here are quite bright & hardly class as low light.
The other night I was photographing candles, getting towards low light but my K7 managed OK. Photographing the river at night however was beyond it, even with a full moon.
Comment by petrochemist posted on How low is low light? at 26/01/2013 - 11:52
johnriley wrote:
Rather than make comparisons though, just bear in mind that smaller formats show more DOF.
Then forget comparisons altogether and just stick to learning what the format you use can do.
There was never a published "120 format-equivalent" figure for the benefit of 35mm users. The only reason we now have "35mm-equivalent" is that digital is not just one format, but many different formats. It gives at least some reference point between cameras.
Surely '120 format' never existed either, 120 film is used in a range of different formats from 6*4.5 to 6*12 from what I've read (My own MF being a 6*9).Rather than make comparisons though, just bear in mind that smaller formats show more DOF.
Then forget comparisons altogether and just stick to learning what the format you use can do.
There was never a published "120 format-equivalent" figure for the benefit of 35mm users. The only reason we now have "35mm-equivalent" is that digital is not just one format, but many different formats. It gives at least some reference point between cameras.
Comment by petrochemist posted on Hyperfocal distance on a DSLR at 25/01/2013 - 14:14
Fortunately T mount adapters are cheap, so getting a better one won't be a major issue.
I've had a similar issue with a M42 lens to which I attached an adapter (rather than having it clip into the camera body).
As it's usefully to have the security of the pin I filed a small recess at the right pint in the base of the lens. Not as ggod as a properly machined one (the lens will wobble slightly on the mount) but it stops it comming off by mistake.
I've had a similar issue with a M42 lens to which I attached an adapter (rather than having it clip into the camera body).
As it's usefully to have the security of the pin I filed a small recess at the right pint in the base of the lens. Not as ggod as a properly machined one (the lens will wobble slightly on the mount) but it stops it comming off by mistake.
Comment by petrochemist posted on T mounts "click" in place at 25/01/2013 - 12:17
I've had basic percripsion glasses ordered off the net for ~£10.
If you get something like these with no fancy coatings or variable focal lengths they should be fone for use in photograhy. (Not the most elegant frames, but who see's that past the camera?)
If you get something like these with no fancy coatings or variable focal lengths they should be fone for use in photograhy. (Not the most elegant frames, but who see's that past the camera?)
Comment by petrochemist posted on Glasses with transition lenses. at 25/01/2013 - 12:09
AuraTodd wrote:
had a loo at your flicker page, is there a shooting star trail in one of your photo's? What lens did you use to take this please?
From the EXIF data on Flickr the lens was a 'smc PENTAX-DA 15mm F4 ED AL Limited'had a loo at your flicker page, is there a shooting star trail in one of your photo's? What lens did you use to take this please?
Not been thrugh the rest of ASa's photos yet, but aircraft trails often look like shooting stars. If Aki's other shots compare with this one I'm sure I'll enjoy going through them at lunchtime!
Comment by petrochemist posted on Moonlit forest at 25/01/2013 - 10:26
Very nice pic indeedy
My low light entry didn't do so well
Smeggy I think you might be pushing even the K5 a bit there