alan_hogg1

<p>Hello People,<br>

Many thanks for your comments - they are much appreciated. I tested my 40 mm pancake lens at f11 against the 24-105 @ 40 mm (using a tripod with live view on a 5DII) , and both photos are equally sharp. The zoom is really an excellent lens, despite the bad press sometimes. Thanks again, Alan</p>

<p>Hello All,<br>

Could I please ask a question that has been perplexing me for a while? With a full frame camera mounted on a sturdy tripod, and using Live View and manual focusing at f8-11 (and raw files), how much practical difference is there in the quality of larger prints (>A3 in size) between the higher grade lenses, between 24 - 100 mm focal length?<br>

If we take the very heavy, expensive Tilt shift lenses out of the equation (because I cannot carry that sort of weight into the mountains on extended backpacking trips), what practical difference could we expect to see between for example, say the old 28 f2.8, the new 2.8 IS and the L zooms at 28 mm (24-70 II and 24-105)? And what about comparisons at 35 mm, or 70 mm?<br>

I know the better lenses resolve more wide open than the less expensive ones (and maybe better in the corners wide open), but is the quality at f8-11 really better for those lenses considered Canon's 'best'? The question is only related to landscape work. Thanks, Alan</p>

<p> </p>

<p>Hello All,<br>

Many thanks for your comments. Sorry about the missing screen snaps. I hope it is OK this time. The lens was 17-40f4L at 35mm f8, no hood!, solid tripod, live view, manual focusing. Both images are at 200% but I can still see clear differences at 100%. The photos are in the 17-40 lens test folder (http://www.photo.net/photos/Alan_Hogg). "left" jpg is upper left corner, "right" jpg is upper right corner. Thanks for your comments. Alan</p>

<p>Hello All,<br>

I did some lens tests over the weekend because I was a bit unhappy about my 17-40L on my 5DII in the corners. I have attached a screen snap which shows at 200% the top left and top right corners at f8, firmly on a tripod using manual focus and live view. Please accept that the setup was fine. I also tested the 24-105, 70-200, 50 and 100 m and all were 100%. Does anyone else see this sort of deterioration in the top right with this lens? It is fine at f16. Thanks, Alan</p>

<p><img src="webkit-fake-url://D3271C8F-C8C5-4767-B536-FC9CB6332A68/image.tiff" alt="" /></p>

<p>Thanks People. I have to admit that I was a bit flustered with the light changing quickly. I will have a play this weekend. Thanks, Alan</p>

<p>Hello People,<br>

I wondered if anyone could please help with a question on how to apply exposure compensation whilst in LiveView on a 5DII?<br>

I was recently trying to capture the last rays of the sun lighting up cobwebs with a dark background and struggled to find a way of quickly adjusting exposure whilst in LiveView. In the end I had to go out of LiveVIew to set the exposure compensation, before going back into LiveView to take the photo. I like the manual focusing of LiveView when on a tripod but just need to get on top of this exposure question.<br>

Thanks for your help. Alan</p>

<p>Hi Ty. Yes one does indeed try to visualise the photo (and choose an appropriate focal length) but that focal length can be anywhere, with adjustments away from normal prime focal lengths if protruding elements etc are in the photo. This is probably splitting straws but I am not sure the word 'redundant' is strictly correct in this context. It may be for certain Leica zooms but not for main stream zooms.</p>

<p>Ty Mickan wrote:</p>

<p><em>Zoom lenses are incorrectly named IMHO; the name suggests that the correct way to use them is to zoom in and out until you've framed correctly. In my post, I was trying to suggest that changing lenses is not a real issue, and that the OP should perhaps start to think of his zoom lenses as covering two or three primary focal lengths ie a user of a 24-70 might use 24-35-50-70...the rest of the range is redundant.</em></p>

<p>I understand why people prefer to use selected focal lengths (eg 24, 36 etc) in a zoom, because that is what they are used to using with prime lenses. But I cannot see how other focal lengths are redundant. Surely one of the advantages of a zoom lens is the ability to exactly frame an image, irrespective of focal length, particularly in situations where one cannot change the distance to the main subject easily. And this occurs frequently in forest for example. Alan</p>

<p>Hi Nila,<br>

New Zealand is really no different from many other places that get regular rainfall and have an oceanic climate. The landscape varies wherever you go from volcanoes (North Island), coastal scenery (everywhere), pastoral scenes and mountains (mainly South Island except for the volcanoes). If you intend doing the tourist walks, you must have a good raincoat, sturdy footwear, and warm layers of clothing. In the mountains, it can be blisteringly hot in the Summer, but it can be teaming with rain or snowing a few days later, so you must be prepared. It is an excellent idea to have a light pack if you want to enjoy the walking, so I would recommend a minimum in camera gear. Even the body and only a single, good quality zoom might suffice. Do you really need to burden yourself with a tripod with modern digital cameras? I do, but photography is my main reason for walking and if the walk itself was the main goal, I wouldn't bother with one. Feel free to ask other questions if you would like to.<br>

Cheers, Alan</p>

<p>Many thanks Everyone for all of your comments - they have been much appreciated.<br>

Perhaps I should have been clearer as to what i want to do.<br>

I presently carry a 5DII, Canon zooms 17-40, 24-105, 70-200 f4 L, plus 1.4 converter plus tripod. When I last looked it was over 6 kg and that is a lot (on top of normal camping gear) when you are walking for a week. I want to try Dan's trick of carrying the body + 24-105 hanging off the pack straps for rapid access whilst walking, but I fear the nearly 1900g weight might be too much. I thought I might be able to substitute the 24-105 with a 50mm macro for access whilst walking. I am not interested in getting 1:1 for insects etc (the 100 macro is just much too heavy for me) but would like a macro occasionally for patterns in nature - cobwebs, or flax in the sun, or backlit leaves or coloured rock etc. I thought if I carried the 5D with the 50 mm macro on the pack straps and leave the 24-105 behind, I could kill 2 birds with 1 stone, with the camera lens weight dropping by 400g or so.<br>

I have a trip next week and will try the 5D with a 50 mm 1.8 first, to see how it goes.<br>

Thanks again for your comments.<br>

Alan</p>

<p>Hello People,<br>

I am trying to find a way to include macro in my lens kit and reduce weight at the same time. I have a 5DII and use it mainly in forests, backpacking etc.<br>

Can anyone tell me how well the older Canon 50 mm macro works using manual focusing and live view?<br>

Also, can you still buy the older style camera cases, we had 30 years ago (am I really that old?) which would fit a 5DII and 50 mm macro? I want something as small and light as possible to suspend from the front pack straps.<br>

Thanks, Alan</p>

<p>Some good responses for an interesting question.<br>

Let me re-phrase the question then, if I might?<br>

"Have you ever wanted to get rid of your large DSLR and replace with one of the lighter interchangeable lens digitals, FOR BACPACKING, WHEN THE OUTPUT IS CONFINED TO A3-SIZED PRINTS (MAXIMUM) OR ON-SCREEN VIEWING?"<br>

Thanks,</p>

<p>Alan</p>

<p>Hi Paul,<br>

If you use a crop sensor camera like a 20D, diffraction kicks in much earlier than full frame 35mm and I certainly wouldn't be using f22. Try the camera on a tripod, at f5.6 and use the remore release to avoid camera shake. Things should look clearer then.</p>

<p>Alan</p>

<p> </p>

Hello People,

Many thanks for your input - it is much appreciated. I will have try some of the suggestions to see if they suffice for my

walking conditions.

Thanks again,

Alan Hogg

Hi there,

 

I know some of you use a Canon 5D with 24-105 lens when bushwalking. I use a large internal frame pack (ca 22 kg all up) to carry all the

gear and food etc I need for 1 - 2 week trips into the New Zealand mountains but have never found a satisfactory way of carrying a camera

to use whilst walking. At present my 400D and lenses goes into the backpack and I use a G9 in a small case attached to the pack straps

for this purpose. I would love to carry the 24-105 lens on the 400D and have it accessible and leave the G9 at home,

 

How do you people do this and avoid:

1. the camera swaying around too much and

2. perspiration under the bag becoming a problem.

3. problems arising if you need to use your hands if climbing steepish tussock slopes.

 

Thanks,

 

Alan Hogg

Re the unexpected exposures using manual focus.

 

I think Brian must be correct here. I used a 400D set on evaluative metering with the

center AF point selected. With auto focusing the center AF point is focusing on Bob's white

target, which turns out grey in the photograph. On manual focus, the entire board (largely

brown in colour) is selected and the resulting photo is much lighter.

 

Evaluative metering must put emphasis on the region covered by the center AF point if

that is selected. Perhaps this explains the occassional overexposed photo.

 

Thanks everyone for your input - it is very informative,

 

Alan

Can someone please tell me how to correct for distortion in CS3? I have tried correcting my

24-105 lens using DPP and the drop in resolution as a result is quite significant. I want to

see if CS3 can do a better job.

 

Thanks!

 

Alan Hogg

Thanks people for all of your comments - they are much appreciated.

 

I have now measured my lenses on my 400D and Bob is indeed correct, that even the lowly S18-55 can

match the L zooms in the centre at f8. It is not so good on the edges or at wider apertures though. The

differences between L zooms and consumer lenses are not as great as I was expecting.

 

This exercise was useful in that it put to rest a suspicion in my own mind that one of my L zooms wasn't

that sharp - there is nothing like using a careful protocol for doing this!

 

I have two last questions.

 

I checked the autofocus on each lens by repeating the tests using manual focus. I was intrigued to see

that in all cases, manual focus gave much brighter exposures than the autofocus equivalents. I was using

evaluative metering. My target was brown colored pinboard with Bob's test targets in each corner and at

the centre. Can anyone explain this please?

 

And the second question. If sensor characteristics contribute to over-all IQ, is it possible that a full frame

sensor like the 5D can result in better resolution for better quality lenses than from say a 400D simply

because of the larger photosites? I think someone may have alluded to this in an earlier post.

 

Thanks again for your contributions.

 

Alan

Thanks people for all of your comments - they are much appreciated.

 

I have now measured my lenses on my 400D and Bob is indeed correct, that even the lowly S18-55 can match the L zooms in the centre at f8. It is not so good on the edges or at wider apertures though.

 

I have two last questions.

 

I checked the autofocus on each lens by repeating the tests using manual focus. I was intrigued to see that in all cases, manual focus gave much brighter exposures than the autofocus equivalents. I was using evaluative metering. My target was brown colored pinboard with Bob's test targets in each corner and at the centre. Can anyone explain this please?

 

And the second question. If sensor characteristics contribute to over-all IQ, is it possible that a full frame sensor like the 5D can result in better resolution for better quality lenses than from say a 400D simply because of the larger photosites? I think someone may have alluded to this above.

 

Thanks again for your contributions.

 

Alan

On Bob Atkins site (BobAtkins.com) Bob states (if I understand it correctly), in

an excellent essay on lens testing, that ultimately, system resolution is

governed by the resolution of the sensor rather than the lens. He suggests that

lens testing is useful to identify defective lenses and that better lenses are

those which exhibit a higher contrast rather than higher resolution.

 

Surely all of the better primes, and L lenses (both primes & zooms) should

therefore show similar results, in terms of both resolution & contrast?

 

If this is indeed the case, why is so much effort put in, by so many people, to

find the best possible "copies" - dreadful word! - of the best lenses?

 

I would be interested in hearing your comments.

 

Thanks,

 

Alan Hogg

Hi there,

 

The Canon 35mm autofocus zoom lenses have a short arc of rotation and the distance scales

are next to useless. The Mamiya 7 manual focus lenses I am familiar with have clear

hyperfocal markings on the lenses, making use of the hyperfocal length a breeze.

 

Alan Hogg

Many thanks for all of the comments - they are much appreciated. I do not want to use

very wide angle lenses with great depth of field because I want to do photo stitching with

multiple images using dedicated panorama heads etc.

 

I do think it is a shame that with sophisticated technology oozing out of every pore of

modern digital cameras, that they cannot provide a simple and accurate way for focusing

at the hyperfocal distance. This has been the most widely used tool for landscape

photographers for the best part of a century.

 

Roll on better technology for producing affordable medium format-sized sensors. Perhaps

then switched on manufacturers will once again give us slow, highly corrected, light

weight, manual focus lenses for landscape work. The technology already exists, and I am

sure there is a market as well.

 

The Pentax 67 and Mamiya 7 are two different examples of these types of cameras.

 

Well now that I have vented my spleen, I can get on with more productive things!

 

Thanks again,

 

Alan Hogg

I have ordered a 400D and am waiting impatiently for its delivery. I would like to use it primarily for

landscape photography and am a bit nervous about auto focus, being familiar with manual focus medium

format gear focusing using the hyperfocal distance.

 

Hyperfocal markings are not etched onto the lenses I have and I guess I will need to resort to the use of

tables to ensure maximum depth of field.

 

Can anyone please tell me if the 400D displays the focus distance at all electronically? If not, how can one

easily focus on the hyperfocal distance?

 

Thanks,

 

Alan Hogg

Many thanks guys - it is much appreciated. I have had a play with the various dof

calculators and have a much better idea of how it all works.

 

I did notice that the various calculators give slightly differing answers. Do they use

different assumptions or do some use approximations instead of actual data? I guess I am

splitting hairs here because the differences are not that great.

 

Thanks once again,

 

Alan Hogg

Hello everyone,

 

Can someone please help with a question relating depth of field and focal length?

 

I am looking at emulating the type of quality I expect from my Mamiya 7 and 65 mm lens for landscapes,

using multi-row stitched digital images.

 

As an aside, the RRS gear seems to be able to do multi-row images relatively painlessly - can anyone

confirm this please?

 

My question relates to what focal length on a Canon 400D (1.6X crop factor) would I use to get the same

depth of field as a Mamiya 7 with 65mm lens? This assumes same aperture, and broadly the same field of

view from the final stitched image.

 

For example, the Mamaiya & 65mm lens has a field of view of approx 57 deg horiz and 46 deg vert. If I

were to use a 50mm lens on the 400D, this should give a field of view of approx 25 deg horiz and 17 deg

vert (similar to a 80 mm lens on 35 mm full-frame). If I stitch 3X2 in portrait mode, this should give a field

of view of approx 51 deg horiz and 50 deg vert - is this correct? With cropping in PS, I should be able to

emaulte the 6X7 proportions, if I wish.

 

But what about depth of field? I assume that a 50 mm lens on a 400D would have less depth of field than

the Mamiya 65, so if I wanted the same depth of field, would I have to use a 40 mm lens on the 400D and

fewer images in the stitching process?

 

Thanks,

 

Alan Hogg, confused!