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Messages - MintMark

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16
EOS Bodies / Re: 6D's Wifi Drain on Battery (?)
« on: December 29, 2012, 05:49:59 PM »
The elevation is the least accurate aspect of GPS in general and I think the manual does mention it.

Sea level is not an absolute concept either... are you sure they weren't 17m waves? :)

17
I understand that the lens always focuses with the aperture wide open, so when you use a f/2.8 lens and shoot a picture at f/5.6 the aperture is open at f/2.8 for focusing and then closes to f/5.6 when the picture is taken.

The 6d centre point is cross type at f/5.6 and vertical line sensitive at f/2.8.

I think in the dark room there are several scenarios...

You can shoot with a f/5.6 lens and AF can lock on to features using the cross type centre point.
You can shoot with a f/4.0 lens and it uses the same centre point, but more light means it can lock onto less distinct features.
You can shoot with a f/2.8 lens and the centre point also has higher precision if there are vertical line features... you'll get more accurate focusing.
You can shoot with a f/2.0 lens and there is even more light, so it can lock onto even less distinct features.

I think there are two factors at work. The maximum aperture of the lens determines how much light is available to the AF system and more light helps it to lock on to harder targets. It can also allow some AF systems to achieve higher precision, as neuro explained.

18
Software & Accessories / Re: Stop Using Instagram
« on: December 18, 2012, 08:04:40 AM »
facebook and flickr already steal copyright...

The linked article suggested that flickr (and google+) were OK... can you explain what you mean when you say flickr steals copyright?

Thanks,

   Mark

19

The 6D actually slightly outperforms the 5D3 in higher ISO settings:

But only very slightly if you apply stronger chroma nr to the 5d3 (nearly no iq loss), downsize the 5d3 shots a bit and then keep in mind that the 6d shots are softer.

Softer 6D shots... do we think it's those shots in that comparison or is it 6D shots in general? It makes me a little nervous... at the moment I'm waiting for comprehensive reviews and tests, but the temptation is growing :) I actually worked out how much I might get for trading in EF-S lenses and a crop camera...

20
I would add high resolution LCD (smaller than 5d3 but same number of dots) and a larger viewfinder than any crop camera.

21
EOS Bodies / Re: Canon EOS 6D Official Specs
« on: September 18, 2012, 05:41:43 AM »
Maybe you'll be able to do all those cool things when you're using your smartphone to control the camera over wifi?

22
Lenses / Re: What to look for when buying a used lens in person...?
« on: June 10, 2012, 04:06:02 AM »
As well as all that good advice, you can do an aperture test.

Set the lens to f/16, look into the front element and press the depth of field preview button. You should see the  blades close to form the smaller aperture. Make sure all the blades close and open again quickly as you press and release the button.

   Mark

23
United Kingdom & Ireland / Re: Bad news for Camera retail in the UK
« on: June 02, 2012, 01:26:34 AM »
Yes, high street is main street and means physical shops rather than web sites or mail order. Independent means not part of a global corporation or franchise.

Jacobs is a small chain of dedicated camera shops... I usually visit there on a trip to London. On the one hand they offer the advantages of a shop, you can walk in and try lenses out (if they have it in stock). On the other hand they sell at near internet prices, so I was never afraid of being ripped off. They always seem expensive for accessories though. And they deal in used equipment too...

I really like the try before you buy experience you get in a shop and I'm happy to pay a bit extra for that. I hope they don't all die.

24
Technical Support / Re: Canon 60D Quick Dial Problem?
« on: April 17, 2012, 12:52:15 PM »
I'm in video mode.

I just tried it with mine... in video mode I have to set Movie Exposure to manual, then the quick dial controls the aperture. I can hear it change and see the setting on the top LCD screen.

Does the quick dial work in other modes? (for example, does it change exposure compensation in Av mode?)

25
Lenses / Re: Astrophotography telescope 'lens'?
« on: December 03, 2011, 05:06:03 AM »
You can read all you need to know and a lot more at http://www.astropix.com/HTML/I_ASTROP/TOC_AP.HTM.

Think of the telescope as a prime lens that is manual focus with a fixed aperture. How you use it depends on what you're photographing. An adapter allows the camera to fit where an eyepiece would normally go. Yes, you zoom in by adding more lenses. For telescopes you can use Barlow lenses (designed to magnify eyepieces). Camera teleconverters work too, but the camera doesn't like the absence of a lens so you have to work around that. The more magnification you add the dimmer the image gets, so it only works for small bright targets (Jupiter and Saturn). For small dimmer targets you need more aperture. A lot of planet images start off as video, then the best frames are selected and averaged together.

For faint targets (galaxies and nebulae) you have to do long exposures. You need a mount that tracks the apparent movement accurately. This only happens when it is properly aligned parallel to the earth's axis. The longer the exposure and the longer the focal length the more accurate the mount and the alignment has to be. This is where the added weight of the camera comes in... it can be a problem if you are operating near the limit of the mount.

Anyway, the link I gave describes the sorts of things you can do with different equipment... you can do quite a lot with just a fixed tripod. There are also man made targets up there too, such as the international space station flying past and Iridium flares.

Hope that helps,

   Mark

26
Lenses / Re: Would Canon make a tele/super tele ef-s lens?
« on: November 17, 2011, 06:11:43 AM »

I think that if you can get what you want with an EF lens then an APS-C user benefits from only using the centre of the lens. The edges and corners of the frame will be sharper than with a full frame sensor.

For 300mm you can try the 200 f/2.8 with a 1.4x converter. That gives you 280 f/4.0 with good quality.
I think if they made a 300 f/4.0 EF-S lens then either the corners would suffer, or the lens would be just as large (and expensive) as the EF equivalent.

Just my thoughts,

   Mark


27
Lenses / Re: 15-85 vs 17-40
« on: May 14, 2011, 03:09:11 AM »
For sharpness you can look at the graphs on photozone... they have results for both lenses on a 50D. They look very similar in performance to me. I don't know about colour rendition... it's more subjective.

I know I'm happy with my 15-85 (even at 85!), but I'm not planning a move to full frame. I'm sorry I've never tried a 17-40.

How about renting one? It won't cost much and you can compare side by side...


28
Lenses / Re: Canon EF 70-300mm f/4-5.6L IS or EF 70-200mm f/4L IS
« on: May 07, 2011, 04:04:35 AM »
I'm not sure we were on the topic :) But since you asked, I love my 200 f/2.8L. I use it 200mm or with a 1.4 extender to give 280mm and f/4.0. It's light and it's black and performs well for me. The only downside is that sometimes you're too close and you can't just zoom out.

I've never used any of the zooms in this thread. When I think about the 70-200 f/4.0 I think "Apart from zooming out, that's a step back from the 200mm f/2.8 that I have." When I think about the 70-300 I think "My current lens gets me 280mm at f/4.0, which is better than 300mm at f/5.6".

In summary, I think my 200L and extender is saving me a fortune! :)

29
I like a shop if you need to try before you buy. I have bought new cameras and lenses from Jessops before because they were cheapest on the high street. London Camera Exchange are also good... I have bought second hand stuff from them and also traded in when buying new. Sometimes they have unboxed kit lenses for cheaper prices. I have bought at Jacobs and was impressed that they sell at cheaper web prices. Often out of stock though.

Another way to try before you buy is to rent a lens. I did this over Christmas and that gave me the confidence to just buy mail order... from Amazon this time. I feel protected by distance selling regulations although I have never returned anything under them. I have bought quite a bit from mpbphotographic too... lenses, filters and a tripod head. Never a problem... I look on buying second hand as recycling :)

30
Lenses / Re: Who do you trust?
« on: January 01, 2011, 05:27:22 AM »
One thing I appreciate about photozone is that they have tested a large variety of lenses in the same way on the same (resolution) body. This means that I can get an idea of how different lenses compare with each other. For example, if I think about buying an older prime lens I can see whether a more recent zoom lens can achieve the same results. I can get an idea of the improvements that a more expensive lens might offer and decide whether it's worth it.

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