All Forum Comments
Comment by petrochemist posted on Info Required on Kenko Variable Tube/Auto Teleplus 2X-3X at 12/06/2010 - 14:46
Have always been a snapper, but am trying to outgrow that status, for which I am following online as well as classroom training.
I think its just the first signs of LBA (lens buying addiction) but so far at least its all been fairly cheap (
Comment by petrochemist posted on Just got my first Penta at 11/06/2010 - 11:18
At Oulton park last month I found my F100-300 produced some nice shots of the Harleys, but at Brands Hatch (and many others) you can't get as close to the track without a media tabbard.
Mike
Comment by petrochemist posted on which motorsort lens? at 09/06/2010 - 22:58
I've recently got a set of plain ND filters for times when I want long exposures (blurring water or perhaps removing people/cars) but I've yet to try them.
I'd like to try UV photography but the UV passing filters start ~£200 which is too much for me, especially as I might find even my older lenses block to much UV.
Comment by petrochemist posted on Is there still a place for filters In a digital world? at 09/06/2010 - 18:49
One Pentax Helicoid Extension Tube K in good working condition for sale.
I don't really know what to ask for it, so make me an offer.
Payment by cheque or Paypal.
Comment by petrochemist posted on Pentax Helicoid Extension Tube K at 07/06/2010 - 23:22
OMG did you see the price for the 300-800mm lens hood, £510, thats more than most lenses cost.
You would think for that price it would have a homing device built into it, so you would never lose it
Comment by petrochemist posted on What lens hood? at 04/06/2010 - 08:18
Thanks
Comment by petrochemist posted on Spam on my portfolio page at 27/05/2010 - 13:25
Make one from an old Ice cream carton and some sticky backed plastic tape.
It certainly feels like a yogurt pot, but optically it's great!
Comment by petrochemist posted on Macro lenses at 25/05/2010 - 22:51
with these lenses you won't get Pattern metering, the camera can only do spot and centre weighted without electric contacts. If it's set to pattern, it'll default to centre weighted.
My guess is that you're looking at some pretty small apertures with the lenses you mention. I find that the cameras tend to underexpose when the light hitting the meter gets very low.
Also with birds on the wing it's possible that your background is bright vs a relatively small, dark foreground. This will confuse the metering system and cause underexposure. If you post some examples we might be able to help more from there.
No difference for either center weighted or spot.
The 500 is F8, (fairly standard) and the scope is F16 at 1000mm (not very usable beyond that.
Backgrounds on all have been fairly neutral.
The birds have been across a lake with trees for a background, with nothing usable.
The bikes with tarmac & grass for most of the background, have actually given me some reasonable shots. They are a bit noisy due to higher iso use, and rather soft focus if they're in the middle of sliding off the track (those few meters closer)
Even test shots of a blank word document (PC monitor white screen) are severely underexposed.
Comment by petrochemist posted on Fixed aperture exposure problems at 24/05/2010 - 20:53
If the one on it's way is too dodgy, I'll probably be unable to resist...
Comment by petrochemist posted on Vivitar Macro Focusing Teleconvertor PK mount at 24/05/2010 - 15:48
Unfortunately, it's nothing so useful!
It appears to be a sprung loaded Converter element, so that when the extension tube is screwed on the converter is pushed closer to the lens, changing the magnification achieved from 2x to 3x.
I hadn't even noticed the spring loading till I found this:
http://forum.mflenses.com/viewtopic.php?t=29068
An interesting toy perhaps, but not what I'd consider truly variable (Implying a zoom like function). The only adjustment ring is actually a simple guide to the effective f.no (loose 2 stops at 2x and three at 3x).
If it had been a helicoid it would have been worth the hassle of M42 adapters, but at least it was cheap enough...
Mike