mike_dodd

<p>Thanks Bob, that was my first idea too but I thought there must be some reason why the connectors are silver otherwise the manufacturers would have made them black (although I have no idea what it is). <br>

So borrowed some different design tubes this lunchtime and took some photos and they appear to be ok. The only difference with these other tubes is that they have large black baffles inside with just the rectangular size of the 35mm sensor hole in the middle. The results looked ok on the camera screen but not looked on computer yet. Interestingly these tubes also had the silver connecters running down the inside.</p>

 

<p>Any suggestions on the best tubes to use with canon 5dii and sigma 180mm macro. The combination gives severe lens flare (a central white blob) with the tubes I have used for years with film and previous digital cameras. Example of the flare at:<br>

http://www.ispot.org.uk/node/10608<br>

it simply ruins the pictures. Most of the tubes I have seen have silver connectors running down the inside which seems a crazy idea guarenteed to increase the possibility of flare however many baffles they also include, why are these connectors not painted black?</p>

in response to the last comment, well no, this is a stacked image, when stacking images you often get this effect of a single piece of dirt appearing several times. so here there are just 4 or 8 (not exactly certain) pieces of dirt and each bit is repeated when the images are stacked together for increased depth of field. You need to look up stacked images to understand this fully. I show a stacked extreme close-up image of this type as this is where the dirt is extremely annoying and where the dust removal technology should have been the most effective but in practice may well be worse than useless.

If anyone is in any doubt about the effect of dust the enclosed shot shows it up very nicely. Its a stacked multiple image for extra depth of field so each of the 8 pieces of dust shows up as a track rather than an individual piece. the shot was taken with a 400d (with all the 'standard' dust reduction) and a 65mm macro, it is a crop of the original shot.<div></div>

I would still like to hear from other people who have actually used the system as I describe.

The specks are unlikely to be pollen or fungal spores as its not the time of year when these are most of an issue. I did have problems with pollen once on the 20d so do know what this can be like. I do take a lot of close-ups 50, 90, 180, 65mm macro lenses and thousands of shots, most of the shots with the 400d have been invertebrates, usually f16-f22 although sometimes less to avoid diffraction issues.

How are people finding the 400D's dust removal system? In test of the 400d I

have seen the reviewers say that the dust removal seems to be good, but none of

them have done specific tests of the dust removal system itself.

 

I would agree that the system appears to be good for normal use BUT not good for

close-ups. Comparing a 20d with 400d under similar usage the 20d gets large

chunks of dirt that I have to periodially clean off with a sensor swab, these

large chunks sometimes show up on 'normal' (e.g. f8 infinity focus) images. So

far these large chunks have not shown up on the 400d photos, probably the system

has got rid of them, so normal pictures are better with the 400d.

However in place of the large chunks of dirt is a fine covering of small chunks

of dirt which do show up on close-ups (e.g. macro lens f16+) and which cover the

whole picture area not just in single large chunks like on the 20d.

Interestingly I have not seen anything like this fine covering of small pieces

on the 20d so it could be that the dust removal system on the 400d is actually

breaking up the large pieces and scattering them everywhere across the image.

The bottom line here is that it can be easier to clean up a macro shot taken on

the 20d than on the 400d as its just one or two large chunks of dirt to be dealt

with rather than the fine scattering of particles over the whole picture area.

 

I would be very interested to hear other people's experience with using the

system for CLOSE-UPS.

I have a 20d and 400d and 24ex flash and 580 flash. The 24ex works fine on both

cameras, the 580 works fine on the 20d but gives 1-2stops under exposure on the

400d. I have tried many combinations of settings with the 400d and 580 flash

but always with the same result of under exposure. The subjects I am trying to

photograph with the 580 are people in a relatively small room so there should be

no problems when using the unit with direct flash or bounced but both give the

under exposure. I have asked canon help about this but so far they have not

come up with an answer, I am hoping it will just be a firmware update that is

needed.

To the original question I think the answer is YES it does matter. The reason I say this from a practical point of view is that I often want to change colour images to b/w and manipulate them as if they were taken through a strong red filter i.e. to give dramatic skies.

When shooting on a 12 bit camera the skies often break up into blocks or zones once manipulated in photoshop whereas from scanned slides or b/w negs from a high quality scanner then they don't. Note here I am keeping the images at 12 or 16 bit then converting to 16bit(if necessary) for any manipulations in photoshop so not 'accidentally' loosing bits along the way. This is actually a major issue with current digital cameras if you want the dramatic black and white skies or other areas where there are fairly uniform gradients.

thanks for the responses. however the photos were taken at 100asa on the digital camera so very little issue with digital noise and the images were correctly exposed, no problems with particularly light highlights or very dark shadows. and it was a proper 12 bit conversion not 8 bit by mistake. the areas that have broken up are in the mid tones which is why i think it is something to do with 12 bits not being enough. For example if it is a blue sky and the channels mixer is taking mainly red then could the actual number of levels of grey be rather few?

I would have thought there is some fancy trick in photoshop to get around this problem.

Comparing a digital image from 20d with similar image from colour

slide film scanned on ls4000 the 20d image �falls apart� much sooner

when you try some moderately extreme channels adjustments to produce

a good b/w image.

For example to get a very dark sky for good contrast with the fluffy

white clouds the same amount of channels adjustment on the 12(16) bit

20d file ends up with blocks of black and grey where the dark area of

sky is supposed to grade down smoothly to the lighter horizon.

Whereas the 14(16) bit scanned slide has smooth grade without these

blocks although if you zoom in further you can see the film grain.

The bottom line here is that for the same size print film is better

than digital under these circumstances.

 

My question is: am I doing something wrong or is it just a fundamental

limitation of images from current digital cameras that they are only

12 bit compared to some scanned images which have a higher bit depth?

 

The adjustment is in photoshop on 16 bit tiff files from both the 20d

(via a raw converter to convert the 12 bit file out of the camera into

16 bit, and using the Nikon software to convet the 14bit scanner file

to 16bit tiff). I have tried this on a range of files from digital

cameras always with the same result of this nasty blocking once you

push them too far whereas with the scanned film this does not happen.

This is actually a rather common occurrence since I frequently want

to achieve results similar to using orange or red filters to increase

the contrast in b/w landscape photos.

I had exactly the same problem with this lens after using it for a few years. Mine was one of the first in uk so is quite old now. I took it back to canon service and they fixed it and for the past 2-3 years its been fine apart from getting a bit loose due to all the use over the years. However I also have a friend who had this problem with one of the 100-400 lenses purchased recently, he took it back to the shop and they gave him a new one which has so far been fine.

 

I must agree with the post that says its a great lens apart from this problem.

Well my original post has generated a remarkable amount of comment most of which I totally disagree with!

The reason I first started thinking about on camera GPS rather than taking a GPS along with me is that its always there and stamps every shot. I�ve used GPS in my work for many years and have a variety of units including sub metre accuracy devices so know all about their limitations but the potential benefits vastly outweigh these limitations.

For example consider the 500 images on my �habitats� page:

 

http://www.amanita-photolibrary.co.uk/photo_library/BI_habitats/index.htm

 

I want to go out and rephotograph these locations many of which I first photographed 10 or 20 years ago to show changes in these habitats (I am an ecologist). There is absolutely no way I could remember where the exact location is to go back to and at the time I took the picture I had no idea that I would want to go back there, so I only recorded the nearest village or name of the approximate area. But if the camera had recorded the location then there would be much less of a problem, even if I had to go to a clearing in the wood for a good GPS reading. Just assume for a moment that decent civilian gps did exist even back then.

 

The other issue is that now on digital we take thousands of shots, not unusual to get through 10,000 or more images per year so labelling them (or transferring gps data to them) is a major problem. So having the unit built into the camera is certainly not a luxury, not should it be expensive since the gps chips are cheap and small. The latest phones and cameras that have gps built in do use real gps not some calculation using the mobile phone transmitters and they are small and not ridiculously expensive.

By the way I take the point about not wanting to let other people know your exact location seriously and if you are selling the image you can remove that bit of data. But as an ecologist looking at the future long after we are dead then I would want future generations to know where I took the images so they could go back and see what effect we are having on the planet. Already there are projects looking at images from 100 years ago and seeing what effects things like water abstraction is having on ecosystems but they need to know the exact location so they can look at the growth on the same trees etc.

Seems Canon have missed a trick badly by failing to put gps capability

in the 5D since this camera is used often by landscape people who all

need GPS capability. Since the gps chips are small and cheap and now

being put in devices such as mobile phones why on earth can't they be

stuck in expensive cameras?

Has anyone come up with a way of including gps functionality in

digital eos camera - other than taking along a second body from

another manufacturer and taking a second shot at the same time and

somehow copying over the data.

Thanks. I wondered about this since I normally use Breezebrowser instead of the canon software, so tried the canon software on a few files and still could not see the distance info. Is there a special place to look, I will go and have a rummage using all the canon viewing software I can find including the two lots that came with the 20d and report back. I do still have all the original .cr2 files.

I have the same setup 20d and hoya circular polariser and if anything find that the shots are slightly underexposed. There can also be shifts in colour compared to the same shot without the filter, suspect this is due to some colours being intensified more than others and the camera having difficulty readjusting its auto colour ballance. In general polarised shots on the 20d can sometimes be rather 'muddy' compared to polarised shots on sensia film.

I wonder how many people have noticed that in changing to the new .cr2

file format for the 20D and later EOS cameras, some of the shooting

information that was available previously has been left off?

The lack of subject distance data may not sound a big issue especially

since it was usually rather inaccurate, however I would very much like

to see this information or other lens settings for the MP-E 65mm macro

lens as the magnification factor or other method of getting a scale is

often very important. For example when photographing an insect

sitting on a leaf, is it 3mm or 9mm long as this would be vital for

identification.

Thanks for all the replies, the Arthur Morris article and excellent photos.

I think I was following most of your suggestions and using the central focus point only on a 20d with 500mm f4 +1.4TC and 10m-infinity focus range.

The thing that was most annoying was that the potential for a really good shot which happened about 3 times in several hours was when the bird was flying directly towards me then turned at the last moment at its closest point (about 15m away) but the lens just gave up and froze when it saw the thing heading towards me fast. I could see it getting bigger and completely filling the viewfinder but not even an attempt at focussing on anything.

Hopefully enclosed is the best picture I got, the bird has put the breaks on and grabbed a mayfly which has just emerged from the water. Unfortunately its very small in the frame and not quite sharp, however the rest of the picture(not shown) does have some of the mayflies coming out of the water so can probably get away with the bird being small in the frame.

Suspect the best chance with birds like this is to find a uniform unpatterned background as in most of the shots in the replies and try to arrange myself where the bird is flying diagonally or parallel as I did here:

http://www.amanita-photolibrary.co.uk/photo_library/Birds/snow_bunting_1172.htm

The snow buntings are relatively easy if you just sit on the beach and pretend to be a bit of driftwood or something as the flock moves in a fairly predictable direction, the ones at the back flying up and moving to the front in a rolling movement.<div></div>

Recently I have been trying to photograph a Hobby (a small bird of

prey that often hunts insects over water). Spent several hours on

differetn days but none of the shots are really much good. The main

problem is that the autofocus won't autofocus on the bird even when

the bird is big in the frame and only the centre autofocus point is

selected. Also the focus limiter is set to 10m-infinity, servo(full

time) autofocus to track objects and IS set to panning mode. using a

20d camera, perhaps a film camera would be better as the autofocus

systems seem still rather better.

The birds move fast and somewhat erratically and are below the horizon

most of the time, i.e. no nice plain blue sky to use (and anyway this

is UK so blue sky rather rare). with practice its quite possible to

pan with them and keep them in the centre of the frame even when big i

n the frame. the best shots are when the bird is coming straight for

me as this is where the light shows the detail best but the camera

autofocus just freezes and gives up. There is no way i could hand

focus but thought autofocus was better than this

Thanks for the replies, very interesting and helpful. However there are still a couple of questions.

 

From one of the suggested references it says that the sony can only be used at full aperture (f2.8) with IR which of course is no good for getting a decent depth of field and will have poor resolution on the edges of the image, is this true?

 

Second question is what causes the 'hot spots' in images taken on the 300d and similar cameras and whether they still occur on the modified versions of these cameras with the IR blocking filter removed. If it is something to do with the coatings of the zoom lenses (or the glass/plastic elements) then I assume the hotspots will still be there even with the filter removed and so even something like the d20a would be useless for normal subject IR with a canon zoom lens. This would be rather surprising as the leaflets that come with canon zooms do not say they can't be used with IR.

Does anyone have any direct comparisons of IR film and digital of the

same scene? I have taken quite a number of IR images on film, see for

example:

 

http://www.amanita-photolibrary.co.uk/photo_library/BW_IR_sepia/index.htm

 

 

 

and I like the overall effect. I am now thinking of trying digital IR

using a modified camera (if I can get hold of one) as the IR digi

attempts so far with an eos300d were all failures e.g. central 'hot

spot', poor contrast and very long exposures. I am most interested in

how the digital camera compares with the large grain and halation of

the Kodak film which I like, in other instances digital 'grain' or

artefacts can look rather unnatural.

no one seems to be properly testing this new bunch of lenses for the digital cameras, perhaps there is some problem with the design that makes them difficult to test.

Slightly different but possibly the same problem, my 300d has been causing problems recently often with 'error 99' or similar. The whole thing siezes up. It is mainly associated with long lenses so I was wondering about the connection and the rubber seals, perhaps the contacts are not pressing tight enough and the strain of a long lens is breaking contact for a brief moment. I have taken about 7000 pictures and it has happened about 10 times in the past couple of hundred images when I have mainly been using these 100-400IS, 500f4 lenses.

In fact with the 500+1.4x converter there are problems perhaps 20% of the time with wrong or no information being sent to the viewfinder and having to waggle the lens about or switch off and reset, I don't class these as siezing up as you can see this problem before pressing the shutter release. On a couple of occasions it has said it is a 500mm f2.5 lens which would be nice but the images just come out too dark when you press the button.

Siezing has also happened once or twice with other lenses.

When taking natural history photos of subjects such as bluebells it is

often very difficult to achieve the colour that the eye 'sees' on film

or digital. The particular way that blue or blue/purple is produced

in nature may be the reason for this. However I was surprised to see

that digital had just as much difficulty, indeed more difficulty in

some cases, in producing the colour than film.

Examples of this are shown on the following web page from images I

took last week:

 

http://www.amanita-photolibrary.co.uk/photo_library/Lesbos/Index.htm

 

The colour on most images is fine, they are straight out of the camera

unadjusted. However if you compare the images of 'blue' subjects,

particularly the orchid CRW_3327.htm, cistus CRW_3358.htm and lavander

CRW_3374.htm they are nothing like the colour in reality. I suspect

no amout of grey cards or colour patches will ever bring them back to

the correct colour.

When taking natural history photos the correct colour is very

important yet this seems get very little mention in digi camera

reviews. How about someone running a test of a bunch of digi cameras

on one of these blue subjects and perhaps compare this with film too

(I know there are plenty of film only tests of this type of subject).

Is it a limitation on the scanner hardware or software or is it

something to do with the processing power of the computer? I ask

this question after a little box came up on the epson 4870 saying it

would take 73 mins to scan 3 6x7 images at 3200 with ICE, compared to

12mins without ICE. I was wondering if it would be possible to save

the normal (12min) scan and the IR scan that ICE uses to clean up the

image then do the processing in batch some time later, say by leaving

the computer to do this overnight. The software would need to be

rewritten but it might make the larger format flatbed scanners much

more productive.

have you found any difference between using this lens on film vs digital. on film it seems fine even at 16 but on digital (the eos700d) it is fine at 35mm and fine in the centre of the frame at 16mm end but this turns to very soft at the edges at 16mm. since the lens performs properly on film i was wondering if it is something to do with how the light hits the sensors when the lens is at its extreme wide setting on digital.