I have been processing some photos from the other weekend (potrait shots from my cousins wedding) and I now think I understand what people mean when they state that the 43 ltd has great colour rendition for portraits.

I'm quite new to the 43 ltd and this was one of the first extensive test runs.

When I process portrait shots I usually change the colour profile in RAW converter to one of the portrait settings. However, with these shots it made no difference. The skin tones were already very natural and pleasing. I hadn't made any changes to the camera settings. In contrast, the few taken with the Sigma 17-70 needed the colour profile changing.

Can the colours from a lens make this much difference or am I imagining it? If it can, I can see why the lens is so popular, especially in the film days where you couldn't select a colour profile after the event.

I have 2 Pentax (well, one Samsung...) original batteries and 2 non-OEM batteries that cost a fraction of the Pentax price. I don't notice any practical difference between the two. The number of shots you get out of either means I rarely change batteries "in the field".

The non-OEM batteries have also spectacularly failed to burst into flames or destroy my camera despite a couple of years of use.

Asking why balk at £50 for a battery when you have spent £1000 on a camera is fine. But if you apply that logic to everything then it soon adds up. I have saved roughly £100 on the two batteries. I also have third party wired and wireless remotes which have saved me a further £70-75 versus the pentax models . That £170 has effectively paid for other parts of my kit (my flashgun, say, plus the batteries and charger for it, and a little left over for some odds and sods).

I don't see it as being tight - it's being sensible. The Pentax branded items may have some slight advantages over the non-OEM products but surely not enough to warrant a 600+% mark-up (in the case of the wired remote).

I've improved but I only started a couple of years ago. In fact I have been going through some of my older shots (ones I was proud of at the time) and I can see some glaring problems with them.

Having said that I still have a long way to go so I'm going to keep asking everyone here for tips and critique.

Also bear in mind that the focus will be different with IR light so if you are relying on autofocus it will be out. Some older lenses have an IR focus scale but otherwise you might want to manually adjust the focus by trial and error after you have the exposure right.

I've sent you a PM with his details.

He usually has some Pentax cameras already converted which may interest you. From my experience I would make sure that any camera you use has focus adjustment available as it makes things much easier.

Manually focusing is possible but you need to adjust the focus. I think that older lenses tend to have a separate IR focus scale on them to help with that.

It's funny - there was a post on the Big American Camera Forum a few days ago asking if it was possible (via firmware) to use the sensor shift to take astro photos. Lots of the responses suggested that the sensor shift doesn't work this way and therefore it wasn't possible. Seems they were wrong

The device sounds quite interesting to me. Matt makes a good point that an astrological tracking tripod would be much more and then you would probably need to calculate the shift yourself (I would guess). This is cheap and portable in comparison. Still too pricey to buy on a whim but if you were interested in trying out astro photography this is a cheaper way to do it.

However, from what I've read astro photos are usually improved with multiple exposures but I would guess that this resets the position after each photo so you are limited to one long exposure.

Are you talking about a permanent conversion (ie. replacing the low pass filter with one that blocks visible light)? If so, handholding would be fine. I have a converted k10d and exposure times are on a par with a normal camera. Not sure if the aerial aspect changes things but I wouldn't have thought so.

Are you sure you want to convert a K7 though? It's still a pretty current model and there are risks with any conversion.

I sent mine to a chap in China. His service was excellent, quick and a lot cheaper than any alternatives I found. I'll pass his details on via PM if you are interested. I would be cautious though - not because of him but because of sending such a high value item by post to China. You may prefer not to take the risk and get it done in the UK, in which case ACS (Advanced Camera Services) convert DSLRs but are pricey.

My first outing with the IR k10d is in the Your Photos forum

link

What I have learnt so far:

- Setting a custom white balance before shooting helps enormously when you are processing. I didn't do that for the photos I've posted so far and getting the classic white foliage look was tricky
- Light and exposure doesn't act in the same way and results can be variable. Hopefully I will improve on this as I learn.
- Certain lenses are not good for IR photography (including most wide angle lenses). The 18-55 kit lens seems to be the best of the lenses I own.
- You have to trust the autofocus. IR light has a different focus to visible light. The autofocus on my k10d was adjusted for me when it was converted. When framing a shot through the viewfinder (visible light) the shot therefore appears out of focus. Live view can help with this.

Cheers

WG

Maybe linked to the wrong page... I downloaded 3 charts from his website with different size centres. You pick the one that suits the field of view of the lens.

This guy has a good article about focus adjustment and explains the details much better than I can.

http://pentaxdslrs.blogspot.com/2008/05/af-adjustment-test-chart-specifically.ht...

I think your technique seems sound and you clearly know a lot more about geometry and engineering than me (the bit about 1.414 etc loses me although I think I understand the concept). It is just the part about the actual focus point which may cause an issue. My understanding is that the red square is an approximation of the focus point rather than gospel truth. Using big blocks of black and white means the camera can only focus where the two meet (i.e. where there is a contrast). If the camera is too high or too low it will "hunt" and not focus.

I've used the techniques of the guy above and was able to get some fairly consistent results.

Hope that helps.

I am no expert here but I think you may want to repeat this with a focus chart designed for the purpose. Most of these have a large black and white area in the centre in order to ensure that the focus point is actually in the middle of the scale. The problem with focussing on a single line is ensuring that the camera is focussing exactly where you want.

Even with single point focussing there is a bit of give as to where the focus point actually is. If the camera has focussed on a different line you may see it as front or back focus.

The camera also doesn't seem to be straight on (at least in the first shot) and therefore any tilt could affect the results.