Deprecated: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in /home/sites/herpetofauna.org.uk/public_html/forum_archive/author_posts.php on line 68

RAUK - Archived Forum - Posts by DrDom:

This contains the Forum posts up until April 2011. Posts may be viewed but cannot be edited or replied to - nor can new posts be made. More recent posts can be seen on the new Forum at http://www.herpetofauna.co.uk/forum/


Forum Home

Posts by DrDom:

Author Message
DrDom
Member
Joined: 13 Jul 2005
No. of posts: 14


View other posts in this topic
Posted: 28 Jun 2006 Topic: Macro lenses



Macro lenses for 350D - to echo what others have said you won't go far wrong with a Canon, Tamron or Sigma 100/90/105

There's a review at:

http://www.orchideen-kartierung.de/Macro100E.html

I've had an old Tamron 90 and a new DG autofocus one, both of which were/are excellent. I chose this over the Canon because it was cheaper and lighter and optically similar. I chose it over the sigma because it has a clutch mechanism to switch from auto to manual focus and this can used with your eye at the camera. With macro lenses you will generally find manual focus most useful. The Canon has internal focussing (IF) which is useful when resting the lens on something (like a beanbag) as it doesn't move. Although more expensive, the Canon may hold its value better than the tamron/sigma. If possible try lenses on your camera, much is down to personal preference.




Dominic Tantram - Guildford
Surrey Amphibian & Reptile Group (SARG)
DrDom
Member
Joined: 13 Jul 2005
No. of posts: 14


View other posts in this topic
Posted: 11 Apr 2007 Topic: Telephoto lens



Good to meet you at Lightwater. Can I make a few more suggestions? Unfortunately they're all more expensive. Canon make some excellent lenses but don't have a good reputation for their budget zooms. The EF 55-200mm @ 125 is unlikely to be great. It all depends what image quality you're after and how much you're prepared to spend...

The EF 70-300mm f/4-5.6 IS USM @ 340 has had some quite good reviews but only focusses to 1.5m.

You won't go wrong with a Tamron Macro (90 or 180), Sigma macro (105, 150 or 180) or Canon 100m macro.

Alternatively you could consider the following:

Sigma 50-150mm APO F2.8 EX DC close focus 1m 460 (reduced size sensor only) 770g

Canon 70-200 L USM F4 close focus 1.2m 445

EF70-200mm L IS USM F4.0 close focus 1.2m 665

Sigma 70-200mm f2.8 EX DG Macro 675

All the prices are guides from a good online retailer and include VAT. You could consider buying secondhand from a dealer which will bet you a warranty and an invoice - I'm not sure you can claim back VAT though!




Dominic Tantram - Guildford
Surrey Amphibian & Reptile Group (SARG)
DrDom
Member
Joined: 13 Jul 2005
No. of posts: 14


View other posts in this topic
Posted: 11 May 2007 Topic: Portrait Photography



Steve - looks pretty comprehensive to meClap, I've only got some fairly specific/nitpicking comments, much of which you know, but then it stops me lurking...

Your approach is very useful, particularly if you can condense it into a set of simple rules with perhaps some basic priorities - it's always difficult to remember everything when you've got an animal posing!

Af taken with one hand whilst holding large tin with other - you can just about get away with low DOF sometimes....

You're right about DOF but I would suggest that shutter speed is the limiting factor here (you can get a good shot with low DOF but never if shaken) so might suggest you actually go with shutter priority. Not sure is its > or < for faster shutter speeds......greater speed/shorter time... Remember to point out this ROT needs to take onboard crop-factors for DSLRs (so use reciprocal of equivalent focal length).

Yes regarding tripods, monopods & bean bags etc also good. You can't over-emphasise the photographer/subject height point!

Vegetation in way/background, diffciult to spot, espacially if you have limited time, if you have it/and the time use DOF preview and/or use your free eye to look at subject.

On lighting strong sunlight causes contrast issues for film and digital. In digital use RAW if you have it and use the camera's histogram to test exposure (before finding subject), expose as far to the right as poss without blowing highlights.

Fill-in flash can be softened using a diffuser, either 20p worth of plastic bought for 30 or make your own from milk cartons, or tape a bit of paper tissue over the flash.

I think you've covered everything else - good luck with weather and have fun

Dom

 




Dominic Tantram - Guildford
Surrey Amphibian & Reptile Group (SARG)
DrDom
Member
Joined: 13 Jul 2005
No. of posts: 14


View other posts in this topic
Posted: 21 May 2007 Topic: Portrait Photography



Rob

Couldn't see your example. However, there are two reasons for fuzzyness, 1) camera shake (from using too 'slow' a shutter speed) and 2) the focus is in the wrong place.

If you're using digital look at the Exif data for the shot to see what shutter speed you used - it should be at least 1/equivalent focal length (see discussion above), shaken photos are blurry all over. If it's a focus issue as Vicar suggests then some part of the picture will probably be sharp. The solution is to use manual focus if you can as he suggest. If I had time I'd look for a technical explanation - it's most likely to do with autofocus contrast and phase detection systems and adder patterns confusing the camera!

Even if you can get them sharp they rarely show up..........




Dominic Tantram - Guildford
Surrey Amphibian & Reptile Group (SARG)
DrDom
Member
Joined: 13 Jul 2005
No. of posts: 14


View other posts in this topic
Posted: 21 May 2007 Topic: Portrait Photography



See tonight's Panorama for an expose ? Rumours abound they're in league with infamous crack squirrels and already abound in leafy Surrey...

However, everyone knows that all those at Stout Serpents are in fact lazy lounge lizards shamelessly exploiting the incipient neuroses of 'joan-average' snake.




Dominic Tantram - Guildford
Surrey Amphibian & Reptile Group (SARG)
DrDom
Member
Joined: 13 Jul 2005
No. of posts: 14


View other posts in this topic
Posted: 19 Feb 2008 Topic: SLR or handheld thingy



Alan and co are quite right that the photographer's more important than the camera. You can take very good shots with a compact camera and they are smaller and lighter. However, you'll find it's more difficult to take a good picture than with a SLR - the cameras are often less responsive, more difficult to focus accurately and the viewfinders (or screens) more difficult to use precisely.

Dolmedes fimbriatus, Thursley, Ricoh GX100 (sorry no herps with this camera)

But - you can only get a photo if you've got a camera with you, so if you're more likely to carry a small all-in-one around it could be useful. I've recently got a Ricoh GX100 to accompany my DSLR and its great - with a fantastic macro, although you do have to get within a few inches of the subject.......so not ideal for anything that might bite or run ...




Dominic Tantram - Guildford
Surrey Amphibian & Reptile Group (SARG)
DrDom
Member
Joined: 13 Jul 2005
No. of posts: 14


View other posts in this topic
Posted: 19 Feb 2008 Topic: SLR or handheld thingy



Keith

It was pretty good... no it's a raft spider, the great raft or fen raft spider (Dolomedes plantarius) is only present in Sussex, East Anglia and maybe Thrapston - but don't confuse the fact I seem to be using a spider as an icon with me knowing much about them.....




Dominic Tantram - Guildford
Surrey Amphibian & Reptile Group (SARG)
DrDom
Member
Joined: 13 Jul 2005
No. of posts: 14


View other posts in this topic
Posted: 24 Apr 2008 Topic: Canon EOS lense question.



I have a Tamron 90mm macro and have found that's very good. The Sigma 105mm macro is also well thought of. Some people also use 60 and 70mm macros on reduced frame cameras like yours. There's a Canon EFS 60mm macro (only fits EFs mount cameras like yours + 450/20/30/40 D) and Sigma 70mm macro.

The Canon 100mm macro doesn't come in L flavour (the Canon designation for top range lenses) but has an Ultrasonic motor for focussing - which is faster than the Tamron and Sigma (70, 105). However, because they focus so close, macro lenses need many revolutions to focus from one end to the other so none are that fast, also autofocus is of limited use for near/small subjects so you tend to end up using manual focus a lot. The Tamron has a one-click clutch to switch between auto/manual which I like. The Canons, with USM focussing, let you manually overide focus.

Thursley lizard Tamron 90mm Macro - wide open

Quality wise you'll find all the fixed focal length (prime) macro lenses very high quality, my Tamron is of equivalent/close optical quality to my Canon 200mm L. Your best bet is to try a few different lenses on your camera and pick the one that you like best - and fits your budget. You can find user reviews at http://www.fredmiranda.com/reviews 

HTH - Dom




Dominic Tantram - Guildford
Surrey Amphibian & Reptile Group (SARG)
DrDom
Member
Joined: 13 Jul 2005
No. of posts: 14


View other posts in this topic
Posted: 27 Apr 2008 Topic: Canon EOS lense question.



Boris

Extension tubes can be useful, Canon sell them individually or you can buy a set of three made by Kenko for the price of one canon one. I've got a set and they're very well made and include contacts to retain metering and autofocus - although you MUST check the manual for each lens you have to check compatibility before you buy. Extension tubes are always useful but they cut down light (as Tim points out light is one of the limiting factors) and you lose focus at infinity so have to remove them if you want to focus at a distant subject.

Another alterative you could consider is a close-up lens you fit onto the front of the lens in the filter thread - a good quality one will cost around 100. You have to buy the specific size for your largest lens but can buy step up/down rings to use them on smaller lenses.

 




Dominic Tantram - Guildford
Surrey Amphibian & Reptile Group (SARG)
DrDom
Member
Joined: 13 Jul 2005
No. of posts: 14


View other posts in this topic
Posted: 04 Jul 2008 Topic: RAUK Fieldtrip 2008



All seems to have gone a bit quiet - are we still trying to do this? I'm happy to do either but'll cast my vote for 1 (Dorset)

Dominic




Dominic Tantram - Guildford
Surrey Amphibian & Reptile Group (SARG)
DrDom
Member
Joined: 13 Jul 2005
No. of posts: 14


View other posts in this topic
Posted: 28 Jan 2009 Topic: Canon EOS 400D



Kev

DSLRs (and most digital cameras) shoot at one resolution which you can not change - although you can change the number of pixels that are captured. Pixels per inch are only really relevant when it comes to printing - where you can re-size your very large but low resolution 72 dpi file to a smaller one at a higher resolution.

HTH - Dominic




Dominic Tantram - Guildford
Surrey Amphibian & Reptile Group (SARG)
DrDom
Member
Joined: 13 Jul 2005
No. of posts: 14


View other posts in this topic
Posted: 19 Feb 2009 Topic: toad crossings



One of the first in Surrey? This guy was at tennis on Tuesday night (17/02/09) in Worplesdon, Guildford- 3m up the fence! Sorry for the ropey phone-picture. Has anyone come across fence climbing? or could a bird have dropped this one?




Dominic Tantram - Guildford
Surrey Amphibian & Reptile Group (SARG)
DrDom
Member
Joined: 13 Jul 2005
No. of posts: 14


View other posts in this topic
Posted: 16 Apr 2009 Topic: Polarizing Filter



John

I'd echo Tim's comments, polarisers can be used to remove some reflected highlights off shiny reptiles when it's sunny and help increase the colour saturation - but it's one more thing to get right (you have to rotate the filter to the right angle) and as Tim points out you lose at least half your light.

If you have an autofocus camera you'll need a circular polariser - this refers to the type - not the shape!

See: http://www.cambridgeincolour.com/tutorials/camera-lens-filte rs.htm

HTH

Dominic



Dominic Tantram - Guildford
Surrey Amphibian & Reptile Group (SARG)
DrDom
Member
Joined: 13 Jul 2005
No. of posts: 14


View other posts in this topic
Posted: 06 Aug 2009 Topic: macro photography for reptiles



Hi Tim etc - to add my two penneth

Macro lenses are very useful as they provide a seamless way of getting in close. I have used a 200mm 'normal' lens with an extension tube for snakes to moderate success but macro lenses are more flexible.

Re shutter speeds - there is a 'rule of thumb' to avoid camera shake of using a shutter speed of 'one over' the focal length in mm. In these days of cropped cameras read effective focal length - so for a 150mm lens on full frame this would be the next speed over 1/150 which would be 1/250, for a crop frame it would be 1/225 [i.e. 150x1.5=225] which in this instance would also be 1/250. The sigma 150mm is very good (as are most prime macro lenses in fact) and is heavy but this can help mitigate camera shake as the setup has more mass/inertia!

Technique also helps reduce shake, use a tripod, bean bag, coat, rucksack etc. If using a tripod/bean bag (and if you have enough time!) use the camera's mirror lock-up or live view, along with a cable release - which helps remove movement caused by 'mirror bounce'.

Many people do use flash to fill-in light the subject and allow smaller apertures/greater depth of field. The 'look' this creates is subject to personal preference. Flash durations are so short that this will help with camera shake - although if there is enough natural light coming in at the same time you can still get blur.

HTH Dominic

Common lizard, 90mm macro on Canon crop DSLR, 1/160 sec handheld. F5

DrDom40039.9612962963


Dominic Tantram - Guildford
Surrey Amphibian & Reptile Group (SARG)

- Posts by DrDom

Content here  topic header