petrochemist

I've never used a professional cleaning service, but they ought to do a better job of it than I do.:oops:

A dead pixels would be one or a small group of individual pixels with no light recorded at all. A fuzzy blob of intermediate shade like this is definitely a shaddow usually caused by sensor muck. It can be difficult to clean off, especially if the cause is something like a pollen grain rather than dust.

Perhaps in some cases linked to the 'very fast' thread, but lets not just restrict it to that... Share shots where timing of the shutter press was critical. To get things started: balloon 4a by Mike Kanssen, on Flickr

Lightning fast :) Lightning at sea by Mike Kanssen, on Flickr

You can't really judge IR exposures from visual light readings. If the light source has lots of IR & little visible you might find IR film requires less exposure than a meter suggests other light sources (like LEDs bulbs, fluorescent lights...) the illumination is almost entirely missing in IR. Sunlight also varies considerably in the ratio of visual & IR, bracketing widely is essential. The nanometer numbers are indeed related to the spectrum, With normal long pass (IR) filters hey are a somewhat simplified indication of where the transmission changes from blocked to passed. Filters are assumed to have a perfect transition where everything below the cut off is blocked & everything above is passed - in reality this normally takes place over a region around 20-30nm either side of the quoted number but some like my 960nm filter are MUCH more gradual (its transition is over 100nm either side). Infrared as a whole goes from ~700nm to 25000nm IR film & modified digital cameras can only capture the very shortest wavelengths of this region. With Film the maximum recordable is around 800 to 900nm dependent on the film used, converted digital cameras typically see to about 1100nm (the point where silicon becomes transparent to IR). FWIW, I've used a wide variety of cheap Chinese IR filters, I've had no issues with them. It may be that they are optically less precise than top of the range filters but I've not seen any improvement when using a proper Hoya R72. they seem the ideal for finding out which cut off you like best. I only shoot IR with digital, which makes things considerably easier, allowing me to use all sorts of strange filters that transmit portions of IR, visual & UV. Metering for these with film would be impossible & focus often wouldn't be practical either. To add to the complications both of these vary with the lens being used (UV transmission of lens varies hugely) so live-view is a great bonus. I'm always impressed by those who manage good results shoot IR the old way!

For comparing FOV 6x7 has an 'crop factor' of 0.477, so to get the same field of view as a 35mm on FF your would want about a 70mm. The negatives aspect ratio is different so perhaps applying the ratio of diagonals isn't ideal.

I still have one of my Dads, an improvement on the ME now I'm more familiar with settings, but as a beginner the ME was great.

As a student I had a M42 300/5.6 on my Pentax ME. Yes the central split prism could go dark, but if you moved your eye slightly it would brighten up again. More tricky to get the prism to work with the 500/8 I brought later but it did with that too when my eye was placed perfectly. In both cases the micro prisms surrounding the split prism worked well to give a useful focusing aid without the need for precise eye alignment. The ME was a nice enough camera but certainly not a top of the range model - it only worked in Av giving me no option of controlling shutter speeds other than adjusting the ISO dial.

If going away (not just to out of the way places) I'd take a laptop as well as a surplus of memory cards. making space on those cards before you go is also sensible. These steps are basic & much better than trying to cobble together a link to a phone to give a little more storage. There are hard drives available that are designed to read from memory cards specifically for this sort of use, but i don't have one & wouldn't use it often enough to be worthwhile. NB the laptop allows a much better review of your shots so you can delete the rubbish & potentially retake some if you find the full scale image doesn't look as good as the cameras screen did. Many people also use on-line services to back up shots while away.

No the rest of us are - that's what I read it as, the mind fills in minor details without us even spotting it..

Infra red Portrait -may14 by Mike Kanssen, on Flickr

Working in a lab I've seen the local certified thermometers being recalibrated. It was a job that took someone several weeks every year & some of the highly precise glass thermometers proved to be out by a significant margin after a few years.Our master thermometers used in the calibration had to be sent away every year for NAMAS recertification. I'd be surprised if a alcohol in glass type sold for photography proved to be accurate at all even if it is reasonably precise (two very different things). Cheap digital ones are unlikely be much worse & for photographic purposes consistency is more important than accuracy IMO.

I don't think it was a Thursday when I took this but it was back when Pentax made the only cameras I used. Gunfleet fog by Mike Kanssen, on Flickr

The donator is unlikely to be the original owner. If they retired nearly 40 years ago, it very probably been sold on at least once.:rolleyes: I suspect I've brought more Russian lenses, in the last ten years than there are Russians who have emigrated to your entire state.:eek:

If you quote the WHOLE phrase yes the remaining options always include the truth. Mr Holmes starts by saying something like 'when you've ruled out the probable' It may be after this exercise of testing & ruling out probable causes, you are left with half a dozen improbable ones. If you've only thought of 3 of the improbable causes the truth may not be among those you've thought off. Your subsequent musings on film don't strike me as being even remotely 'whatever remains'

Several good summaries of rights, but it might be worth pointing out some stock agencies etc. insist on releases whatever the legal situation.

Oulton Park Grid 1 by Mike Kanssen, on Flickr

Thruxton BTCC 2018 by Mike Kanssen, on Flickr

I don't find polarisers are in the fit & forget category. The degree of rotation often has to be altered to get the best for each shot, sometimes BOOSTING reflections rather than reducing them. As above they're troublesome on wide lenses, and subtly is often needed in their use. Personally I often use IR when I want to darken skies (it can pick out clouds you didn't realise were there), but I guess that gives an even more unnatural look, with complete lack of subtly! :rolleyes:

That's an issue with adapters I'd not thought of, I've had a few long lenses unexpectedly clipped on FF, I'd better check which adapters I've used... With the NEX6 I've not had many issues with the menus, but that's probably just because I try to avoid menus, dedicated controls are much better at least for anything used regularly.

Surprisingly the Nex 6 is a step up from the Nex7. It came out about a year later & did away with the non standard flash shoe. I still find the Nex6 to be a very capable camera, even if I do use the A7ii a lot more. All the lens adapters should work fine on either FE or E mount systems, but perhaps some of your lenses won't cover the larger sensor. The collapsible version of the Industar 50 may not be your standard pancake & is perhaps a little long for APSC, but it's small & great fun IMO A bit wider allows the 24mm/2.8 from the Pentax auto 110. When adapted it's fixed aperture, but at 12g I don't think you'll get much lighter! The 24mm is designed for a smaller format, but IIRC it covers APSC adequately (unlike its 18mm brother) Sticking more to your focal length specification there are 35mm c-mount lenses around that cover APSC, they're a little bigger than either of my first suggestions & not quite as good optically, but quite affordable & fun to play with.

BTTC grid in IR by Mike Kanssen, on Flickr

Not totally, I know ones APSC & the others FF but can't reliably remember which is which, I'm no better with Canon. All my Canon mount lenses are from film days & I probably have as many FD as EF. All of those as well as a great many others will adapt to any of my mirrorless bodies, the new RF lenses like those discussed up thread, I can't work with (or Nikons Z mount for that matter) :(

I still use a few mirror lenses, (500/8, 500/5.6, 600/8, & 300/6.3) they are awkward to focus, but so is any manual extreme telephoto and the they have a significant advantage in size/weight. My 300mm is actually a modern design, but being designed for MFT is only usable on a fraction of my bodies. I also use a refractive telescope that mounts via a T2 ring & works very much like a fixed aperture lens. Its long, slow & moderately heavy but with care gives fair results at 1000mm f/16, even my gimbal won't hold it steady enough to get usable results at 4000mm (which is f/64) The new 600/11 is both longer & heaver than my old 600/8, but it supports AF, has IS & nicer Bokeh I don't have an 800mm lens unless via a TC, so I'm sure I'd find either of these new lenses a fun addition to my options, but the price will be more than I can justify, and they won't fit any of my bodies either even with an adaptor. Canon don't make either FX or DX :)

My copy of 'Wratten light filters' (a very useful reference for technical data on filters) lists #15 (G) as very deep yellow, and shows spectral data close to that of a 530nm long pass filter (50% blocked at 530nm). The letter code of G is often used by other manufacturers so it's probably the same filter. Here's the spectra: 530nm filters work OK for high colour IR on converted digital cameras, but I prefer a slightly longer cut myself. I've never used IR film, but I seem to remember hearing it tends to see less far into the IR band than converted digital cameras (which see to ~1100nm) How far into the IR films see will depend on the film ~900nm is listed for Aerochrome. With this added region Aerochrome might be expected to see ~twice as much 'light' as visual films would through the same filter.