Masochistic tendensies?

JKT · Post by **JKT** » Mon Jun 25, 2007 3:22 pm

At least that is the only explanation I can think of for using only the EF-S 60 macro lens instead of longer ones for a whole day.

Trying to approach them close enough was a real pain. I'd quess that 5% of attempts led to a picture. I have a feeling that 100 mm lens would have allowed at least a third of the the shots that were now lost. There were some acceptable shots, though...

Lasiommata maera (Large Wall Brown):

Ochlodes sylvanus (Large Skipper):

And then it got cloudy, which made photography much easier - after finding something to photograph...

Melitaea athalia (Heath Fritillary):

I probably should mention that the last one is quite common here...

Dave Mac · Post by **Dave Mac** » Mon Jun 25, 2007 3:59 pm

Hi JKT, I use a 300mm lens that focuses down to about 5ft. At that distance you can nearly fill the frame with a large butterfly and get an acceptable shot from about 8ft. away. For the liittle guys such as small skipper inserting a 36mm spacer will make the lens focus down to about three and a half ft. I used to chase bugs with a 100mm lens and its definatly easier with the 300 mm and I get more keepers. You still have to find them though.
Cheers
Dave

Chris · Post by **Chris** » Mon Jun 25, 2007 4:01 pm

Very nice pics... the real advantage of using a shorter lens is that you get more depth of field and less noticable camera shake, so that sharp pics like yours are the norm! Worth the 95% that flew away!!?

Regards, Chris

Rogerdodge · Post by **Rogerdodge** » Mon Jun 25, 2007 4:26 pm

... the real advantage of using a shorter lens is that you get more depth of field and less noticable camera shake

I agree with the camera shake point - this is the distance of apparent subject movement for an angular movement - double the subject distance, and double the movement blur.
However, I do not agree with the depth of field statement.
For a given magnification, the d.o.f. is the same for the same F stop regardless of focal length.
However, there is a compression of perspective with a longer lens that can lead to a perception of a shallower d.o.f.
At least that is my understanding.
Roger Harding

JKT · Post by **JKT** » Mon Jun 25, 2007 4:59 pm

Rogerdodge wrote:At least that is my understanding.

Mine as well.

Dave Mac,
Your system is on my list of possible acquisitions (sp?). It would be the f/4.0 IS version, but that may take awhile ... MP-E 65 arrived today.

Rogerdodge · Post by **Rogerdodge** » Mon Jun 25, 2007 5:26 pm

I would love to hear of your impressions of the MP-E 65.
It is way up there as my next expenditure.
Please post some pics soon!.
Are you using it with the twin flash MT24EX (I think) - I have this and use it occasionaly - it is brilliant.
Roger

JKT · Post by **JKT** » Mon Jun 25, 2007 5:46 pm

Rogerdodge wrote:Please post some pics soon!.

Not quite yet as...

Rogerdodge wrote:Are you using it with the twin flash MT24EX (I think) - I have this and use it occasionaly - it is brilliant.

...I don't have the MT24EX. At least not yet.

The lighting is going to be a problem for some time, as my current options don't really work. I have the Sigma macro flash (it is NOT a ring flash), but it does not illuminate close enough for this lens. Nor does my homemade flash diffuser. I need to design something ... or deplete the bank account even further.

On the other hand, the pictures seem to be pretty sharp, but 20 second exposure is a bit much for living specimen.

Rogerdodge · Post by **Rogerdodge** » Mon Jun 25, 2007 6:50 pm

Before I got the MT24EX, I made up a really nice little twin flash unit.
I made a boomerang shaped piece of 3mm thick aluminium, about 10" wide (forgive the mixed measurements) with a hole drilled in the centre, and one at each end.
I got 3 tripod type screws from Jessops, and used one to attach the boomerang to the tripod mount on the lens/camera body, and the other two to attach the end of the off-camera-shoe to one end, and a slave to the other. Then I attached two small, second hande flash units and set them to manual.
Much experimentation with exposure and distance followed with a nice little table worked out.
Didn't cost a lot, and all painted black, looked pretty pro'!
HTH
Roger

Chris · Post by **Chris** » Tue Jun 26, 2007 8:14 am

Rogerdodge wrote:
... the real advantage of using a shorter lens is that you get more depth of field and less noticable camera shake
I agree with the camera shake point - this is the distance of apparent subject movement for an angular movement - double the subject distance, and double the movement blur.
However, I do not agree with the depth of field statement.
For a given magnification, the d.o.f. is the same for the same F stop regardless of focal length.
However, there is a compression of perspective with a longer lens that can lead to a perception of a shallower d.o.f.
At least that is my understanding.
Roger Harding

Oh. Well I'll bow to the majority... I read that if you're taking a picture of your wife eating a sandwich, i.e. with little magnification, then there is no perceivable difference in D.O.F. But at high magnifications, such as 1:1, then a shorter lens creates more depth of field behind the point of focus. Books, hey, what are they good for!?

Chris

Bryan H · Post by **Bryan H** » Tue Jun 26, 2007 10:21 am

Hi JKT

I'd say those shots are more than 'acceptable'!

If you were stuck with the shorter lens, think what it would do for your stalking skills. Speaking as a 105mm man, that's half the fun for me!

I try not to think of the shots I didn't get as 'lost'. I did just miss a Brimstone recently as I took up my position. Frustrating, but how satisfying it will be when I finally do get close enough one day!

Bryan

JKT · Post by **JKT** » Tue Jun 26, 2007 5:21 pm

Bryan H wrote:I'd say those shots are more than 'acceptable'!

I know.

Bryan H wrote:If you were stuck with the shorter lens, think what it would do for your stalking skills. Speaking as a 105mm man, that's half the fun for me!

I wasn't stuck in any way. The longer ones were hanging in my belt all the time. I just wanted to know how difficult it is and what kind of results I would get. It was excellent practice as you say.

Bryan H wrote:I try not to think of the shots I didn't get as 'lost'. I did just miss a Brimstone recently as I took up my position. Frustrating, but how satisfying it will be when I finally do get close enough one day!

There are too many missing species on my pages to give one any extra chance. Once I have A picture, I can try to the get THE picture.

The time and place in question were such that the chances of finding anything new were nil.

sidwemn · Post by **sidwemn** » Wed Jun 27, 2007 8:40 am

Regarding Depth of Field. A useful tool is a Depth of Field Calculator. A link to an online version is below. Have a play with the values and see what affect changing the parameter have.

Changing focal lenght doesn't affect DOF provided the distance from the subject changes by the equivalent amount

ie DOF the same using 100mm lens @ 1.0m to 400mm lens @ 4.0m

Does this make sense?

Cheers
Martyn

http://www.dofmaster.com/dofjs.html