petrochemist

Joined: 27th February 2010

All Forum Comments

Topics Created Topics Contributed Forum Comments Photo Comments

All Forum Comments

petrochemist
Great set!
I like the way the rider in the last one appears to be throwing his bike away in disgust!

Comment by petrochemist posted on Brands Hatch, April 13 (not the Chinese Grand Prix) at 15/04/2013 - 14:03

petrochemist
I suspect what you have is an ND8 & a ND2 which should give 3 stops & 1 stop respectively. (ND8 reduces the light 8 fold which is halfing it 3 times). Photographic big stopper type filters are typically ~£100 You could always try out welding glass...
V cheap, but you have to arrange your own mounting & it gives a colour cast.
Shades 8-13 are generally available, with the higher numbers blocking more. Even a shade 8 will give you a LOT more than you have here.

Comment by petrochemist posted on ND Filter Help at 15/04/2013 - 08:30

petrochemist
Smeggypants wrote:

Just to be clear I wasn't suggesting leaving it on Point and shoot mode all the time while actually using it. I was referring to a mode to leave it on while switched off so that if a fleeting moment happens you can just switch the camera on and get the shot without having to worry about setting any parameters.
Exactly how I prefer to work. In P mode it just takes a quick flick of one of the wheels to control Aperture/exposure. Yet it's still available for grab shots.

IMO the optimal sharpness of a lens is only really of interest if you are doing focus stacking. Aperture has a massive effect on DOF, which in turn drastically changes the image. It can't always be used at the best setting for DOF due to it's effect on shutter speed - ISO has it's limits & unfortunately they're lower on my K7 than the K5...

Comment by petrochemist posted on "What goes round, comes around" - it must be F8 at 13/04/2013 - 09:01

petrochemist
mattie wrote:
Ta all, useful insights - shame that it seems I'll lose the simplicity of fill-flash through TTL.

As an aside, why did Pentax discontinue TTL support? Cost-cutting, or because P-TTL is seen as the future?
I believe digital sensors reflect the light more than film which alegedly causes issues with TTL (which works by looking at the light reflected by the film during exposure). I strongly suspect that cost saving is also a factor though as it means the camera doesn't need the extra sensor

P-TTL works differently by produceing a preflash & monitoring the illumination produced by that with the camera's main sensor. In use it is generally as simple to use as TTL unless you are using optical slaves to set off other flash guns. (If you try the preflash sets of the slaves, which are then recharging during the main flash). The effect is not dissimilar to the anti-red eye pre-flash.

I have to admit I find P-TTL invaluable for macro, where I hold the flash in my left hand at various angles/distances from the subject. Manual would be totally impactical here as the flash-subject distance is too uncontrolable.

Comment by petrochemist posted on Auto flash control, TTL and P-TTL at 12/04/2013 - 12:53

petrochemist
mattie wrote:
Ta all, and apols for delay in getting back to this.

Just to recap, the Sigma wouldn't give the full effect due to it being designed for 35mm frame, would the 10-17 or is it simply that the 10mm angle isn't quite side enough?

I've found a new 10-17 going for £370 which is tempting me, but if the Samyang is similarly useful I'll go for it given the significantly lower price.
The 10-17 is designed for APS-C giving a maximum 180° diagonal FOV.
But it fills the frame & doesn't give the circular image. If thats what your after your only choices are the screw on adapters - most of which are appallingly bad.

Comment by petrochemist posted on Sigma 8mm fisheye at 07/04/2013 - 16:50

petrochemist
I'm used to Colin driving a black Ginetta, seems a rather drastic way to revert to his old colours. Glad to see he got out OK.
Not much left of the body but perhaps the engine may have survived as the fire appears to be more at the back, in any event an expensive incident.

Great photos as always Simon!

Comment by petrochemist posted on Easter motorsport double - Thruxton & Oulton Park at 06/04/2013 - 07:46

petrochemist
Prompted by this thread I've checked up my the recent photographic spend (purchases within last 3 yrs).
Bundles complicate things somewhat but, Cameras average ~£130 & Lenses average ~£40.

So I don't see why my wife would be worried, unless it's fear of downing in all the accessories.

Comment by petrochemist posted on Poll : How many members tell their partner everytime they buy a new piece of kit? at 25/03/2013 - 16:19

petrochemist
I don't tell my wife about everything, there are far too many minor bits & bobs and we both have things to do.
When things come delivery is usually made when I'm at work, so she get to sign for it. So Jess knows something's come even if not what it is.

We have a joint account, I earn the money that goes in & we both spend it. Some how we must try to get to the point where we each only spend half of it!

Comment by petrochemist posted on Poll : How many members tell their partner everytime they buy a new piece of kit? at 20/03/2013 - 00:24

petrochemist
Mine are used similarly to yours, but I've further modified my adapters by drilling/filing a slight recess for the pin that locks PK lenses in place.
After making this recess, I use thread lock if the M42 thread is loose enough for the lens to turn.

Comment by petrochemist posted on Question about M42 to PK adaptors at 13/03/2013 - 12:55

petrochemist
kh1234567890 wrote:
petrochemist wrote:
FF d-slr
Dream on. Pentax currently does not have a 'kit' zoom that works on full frame. The appearance (or rumours) of such a lens would give a hint of a Pentax FF DSLR on its way.
No dream of mine - I won't be buying one, My dream is the K5II

Whilst Pentax doesn't MAKE a kit lens for full frame, it has designs from film days that could be produced again(& the skills for Digital optimisation which would probably be wanted). If they are planing on going FF why would they release the lens for it in advance?

There are probably even enough old kit lenses on e-bay to provide one for each FF DSLR that Pentax is likly to sell

Comment by petrochemist posted on Rumoured announcement of several new DSLRs at 12/03/2013 - 16:43

Proudly supporting Pentax User

Samsung Logo Asahi Pentax Logo