Author Topic: Questions and Answers on IR  (Read 93408 times)

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Offline pcabot

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Re: Questions and Answers on IR
« Reply #90 on: September 14, 2009, 02:03:56 PM »
Does anyone know how do I check if a Hoya R72 filter is a genuine one ?

I bought it online from this vendor (through amazon):
http://www.videocameracenter.com/ 
by doing a search for "hoya r72".

It looks genuine to me....but what do I know ?
I could contact them, but I doubt that will say it is a fake :)

Apart from that, I will try shooting with the white balance setting that you mentionned ( 2200k - 2450k G9  ), and also I would try disabling the DRO completely...

Thanks,
Philippe

Offline winjeel

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Re: Questions and Answers on IR
« Reply #91 on: September 14, 2009, 03:23:16 PM »
I wish I could help you. I have no idea. The only things I ever buy from the net come via Amazon.
JapanesePhotos.Asia; Some basic photographic how to's.
Sony the200, Minolta 28mm 2.8, 50mm 1.4, 70-300mm Gregarious, 100mm 2.8 macro.

Offline Rob aka [minolta mad]

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Re: Questions and Answers on IR
« Reply #92 on: September 14, 2009, 04:25:33 PM »
The packaging and case give the appearance of being genuine.
Its just strange why the colours are not coming out as id expect.

I really dont know what else to suggest ???


Rob

Offline Rob aka [minolta mad]

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Re: Questions and Answers on IR
« Reply #93 on: September 14, 2009, 04:54:01 PM »
I was just looking at the raw files again, and i see that the Saturation is set to High, and the Sharpness is set to hard.
Im sure the shrpness wont have an effect, but not sure about the saturation ???
Id leave everything on standard and make sure the DRO is off, as this will affect the exposure when reviewing the histogram.


Rob

Offline Stef.

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Re: Questions and Answers on IR
« Reply #94 on: September 14, 2009, 05:36:19 PM »
Hehe- waiting for my A100 to come back from groovyone's recommended place in the US. Should be here next week! Can't wait...
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Offline Rob aka [minolta mad]

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Re: Questions and Answers on IR
« Reply #95 on: September 14, 2009, 07:59:48 PM »
Hehe- waiting for my A100 to come back from groovyone's recommended place in the US. Should be here next week! Can't wait...
Stef.

I have considered getting an A100 and getting it converted, but i like the long exposure effect that you dont get with converted camera's.
Cant wait to see some of your images with it Stef.


Rob

Offline groovyone

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Re: Questions and Answers on IR
« Reply #96 on: September 15, 2009, 04:46:59 PM »
Hehe- waiting for my A100 to come back from groovyone's recommended place in the US. Should be here next week! Can't wait...
Stef.

Sweet!  I am interested to see how well it works in the hands of someone with actual talent!

I dunno Rob, that sounds like an excuse...

hahah

Offline Stef.

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Re: Questions and Answers on IR
« Reply #97 on: September 15, 2009, 06:18:36 PM »
Rob- on the other hand the long exposure effect can be a pain particularly when shooting landscapes as trees and bushes usually don't stand still long enough. This is actually the main reason for me to get the camera converted. i don't mind the pain to attach a filter but I do mind the 1 min exposure times that occur regularly.
Let's wait and see. On the other hand instead of getting a camera converted for a couple of hundred pounds/dollars you might as well buy a second hand samsung camera and remove the IR filter yourself as it is easy to do. I actually think you might come cheaper buying one of those plus lens than investing in an A100 and getting it converted. I might be wrong though... ???
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Offline groovyone

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Re: Questions and Answers on IR
« Reply #98 on: September 15, 2009, 07:10:52 PM »
I have a full spectrum F828 that can soot RAW.  The nice thing about that vs a converted SLR is you can see the IR effect on the EVF or LCD, and you can do some interesting shots with a full spectrum camera, but it has an effect closer to the full modded camera than the filter method.

Offline pcabot

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Re: Questions and Answers on IR
« Reply #99 on: September 16, 2009, 02:26:55 PM »
Hi Rob,

Here is an attempt with the camera settings set to :
 - DRO off
 - sharpness, saturation, = normal
 - exposure: 80 sec
 - F8
 - ISO200

http://philippecabot.com/infrared/infraredv13.arw  (13MB)

The histogram looks a lot better on this image, but I still cannot get the colors out of the image....
The sky seems a bit more colored though...

I contacted Hoya by email to ask them how to test their filter, but I doubt I will receive an answer... :(
I think I will contact my vendor to see what I can do to exchange the filter.

One last thing: you are using the latest firmware (v4), right ? I am just trying to see what could be different in your settings compared to mine...
Could it be the SAL16105 lens ??? I doubt it...

Do you recommend another filter (cokin?) that I can use to do infrared with false colors ?
I *really* want to do infrared (without any modding) ...

Thanks again
Philippe

Offline groovyone

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Re: Questions and Answers on IR
« Reply #100 on: September 16, 2009, 03:30:44 PM »
Philippe,

I am looking at your RAW and you won't be able to get much with that.  I see very little if any IR effect.  My normal settings with the filter were ISO 200, f/7.1-f/8 and 25-30 seconds.  You should see some obvious IR effect in the trees.  Was there a lot of direct sunlight when you shot this?  Do you have another lens you could try?

This is how mine look coming out of the camera:
A700, 16-80 Zeiss, R72 filter, f/5.6, 30s exp, ISO200


I took a quick crack at it with IDC (click photos for full size):
As is:


WB off the brightest tree, +1Ev, +60 Contrast, stretched the histogram to fill the range:


WB off the brightest tree, +1Ev, +45 Contrast, -100 Sat (B&W), stretched the histogram to fill the range:
« Last Edit: September 16, 2009, 03:42:45 PM by groovyone »

Offline Rob aka [minolta mad]

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Re: Questions and Answers on IR
« Reply #101 on: September 16, 2009, 08:36:18 PM »
Having had a look at the RAW file, i am now conviced of a couple of things.

1: The filter is either a duff/fake and will not allow full IR

2: The lens is producing a massive 'hot spot' and not allowing for IR
(the reason i say this is in the last RAW file, there is what looks like a slight colour differance, centrally, but covering most of the image. Almost like a hazy effect) and checking the other images, its much the same.


Id go so far as to say that ist the lens !
As for other filters, i'd be inclined to try another lens first.
If you really want to do lots of IR, then id gor for the minolta 35-70 f/4
They can be picked up for around £15 in the UK, and then get a adapter ring so that you can use the filter on the minolta lens.

If it had been any camera other than the A700, id have said that it was the camera preventing it, but the A700 is great for IR.


Rob

Offline pcabot

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Re: Questions and Answers on IR
« Reply #102 on: September 17, 2009, 05:38:17 AM »
Hi Groovyone and Rob,

Wow. You guys are great.
Thanks for doing all the conversion tests and investigation ! I really appreciate...

I think you are right: I am also suspicious about the SAL16105 lens for the big hopspot.

Yes I have another lens: the sony 50mm F1.4 (filter 55mm). What a jewel !
How can I put the 62mm filter on this lens ? I guess I simply need to buy a step up ring like this one ?
http://cgi.ebay.com/55mm-62mm-55-62-mm-Step-Up-Filter-Ring-Stepping-Adapter_W0QQitemZ230361975541QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item35a2a4caf5&_trksid=p3286.c0.m14 
Can I try without

Perhaps this lens has more chances to work because it has a fixed focal length...
Once I know that the filter works with that lens, I will buy the recommend lens from Rob: the Minolta 35-70 F4. I looked on ebay, and the prices are quite high though (99$?) http://cgi.ebay.com/Minolta-35-70-AF-f4-MINI-beercan-lens-for-all-sony_W0QQitemZ250496536411QQcmdZViewItemQQptZUK_CamerasPhoto_CameraAccessories_CameraLensesFilters_JN?hash=item3a52c1cf5b&_trksid=p3286.c0.m14

If you know good deals on other used minoltas for doing IR, let me know ! I am seriously looking in doing IR with my a700 ! :)

I can't wait to try the filter on my other lens, to see if I get the same effect or not.
I will keep you posted with the results...

Thanks again for the followup,
Phil from Montreal



Offline groovyone

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Re: Questions and Answers on IR
« Reply #103 on: September 17, 2009, 02:57:40 PM »
Hi Groovyone and Rob,

Wow. You guys are great.
Thanks for doing all the conversion tests and investigation ! I really appreciate...

I think you are right: I am also suspicious about the SAL16105 lens for the big hopspot.

Yes I have another lens: the sony 50mm F1.4 (filter 55mm). What a jewel !
How can I put the 62mm filter on this lens ? I guess I simply need to buy a step up ring like this one ?
http://cgi.ebay.com/55mm-62mm-55-62-mm-Step-Up-Filter-Ring-Stepping-Adapter_W0QQitemZ230361975541QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item35a2a4caf5&_trksid=p3286.c0.m14 
Can I try without

My 50 f/1.4 did pretty well for IR, so give that one a shot.  For now, you could try just taping it to the lens at first.  That lens has a pretty flat front surface on the lens body, so you may be able to carefully hold it in front too.

50mm f/1.4 - this is on my modified A100, but you should get good results on the non-modified camera too.
« Last Edit: September 17, 2009, 03:03:13 PM by groovyone »

Offline pcabot

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Re: Questions and Answers on IR
« Reply #104 on: September 17, 2009, 03:00:16 PM »
Thanks for the tip.

This morning I decided that I need to go all the way if I want to do some good IR: I just bought on Adorama a used minolta 35-70 f4 with a 49mm Hoya R72 filter, jus to be on the safe side.
I want to do some good IR ! :)

I will keep you posted when I receive the gear... can't wait!

Thanks,
Phil