dfperrault

I plan to shoot a video of a violinist dancing while playing in an outdoor non performance setting.

 

Please comment on the following items

 

1. Violin contact audio transducer connected to small recorder hidden on musician

Zoom H5 or the more compact F1 or F2

 

2. Sync Audio and Video

- Is is sufficient to do one handcap in the camera so it is picked up on the audio and video in order to sync.

- Are there better ways to create a reference to sync audio and video.

 

3. Slo Mo

Would the video be awkward if I did some slo mo video but had the audio at normal speed.

Thank you. I know of Jack. But this was a different guy. I will contact the camera club.

I worked with Avid Technology in 1991. The Boston Camera Club (was then) an excellent collegiate of enthusiastic and generous Photographers, I suggest that you contact them for assistance, I reckon someone there will point you in the right direction.

 

Additionally - Thurman Naylor (nickname Jack) was well known for his collection of many Photography items. I believe he had a museum in his house. Unfortunately time did not permit for me to visit Mr Thurman when I was in Boston. Jack’s collection might be the one to which you refer and you could follow that line of inquiry, also.

 

WW

Does anyone now the name/contact info of the person who claims to own (ed) the largest f/1 lens collection in the world?

He lives in Brookline, MA. The collection was on ebay last year.

 

moderator note - this thread is moved to Casual Photo Conversations as likely more members might notice it and assist the OP.

Can the typical camera sensor cleaning swabs be used to clean 35mm slides, when used with a cleaning solution like pec? Or is the foam too course and could it potentially scratch the emulsion? I have seen these for sale at $40/1000 on alibaba.

Don't take this the wrong way but...

“There seems to be some perverse human characteristic that likes to make easy things difficult.” -Warren Buffett

You could however, fix one image visually, doing this all on an Adjustment layer, then drag and drop it on all the others.

Or create a preset of the fix visually and copy/paste them to all others in say Lightroom/ACR.

 

Sorry, I have not explained my goals in enough deals. I started off posting a color correction question based on a target.

 

There are two levels of adjustment I need to do

1. Color correction for ambient conditions (this is not that difficult)

2. Color/Exposure restoration of the target print to match a published museum quality version

 

Each of the 100 target images have been collected from different sources, storage conditions, different print dates etc. over the past 150 years. The target Images need to be individually corrected to match the higher quality version.

 

Sure, I can do this by eye for the 100 prints. 25-50hrs of work. Just curious of there are some computational solutions that are less subjective.

-

If I want to mathematically match the colors/exposure of a target image (image to be corrected) to a reference image, could I do this by calculating the difference or ratio of the two images in PS, and scale the target image to match the reference image. I would have to make sure they are physically scaled to the same size /alignment. Would it be better to do each color channel independently in RGB of CMYK?

 

Method 1 - Differential Error

Layer 1 - Reference Image

Layer 2 - Target Image

Layer 3 = (Target - Reference) / Reference

Layer 4 = Target / (layer 3 +1)

 

Method 2 - Ratio

Layer 1 - Reference Image

Layer 2 - Target Image

Layer 3 = Target / Reference

Layer 4 = Layer 2 / Layer 3

 

 

If this method works, then I could do this in Matlab, and have all the 100 images processed in a minute or so. But I suspect it is not that easy.

BTW, I just realized what Q&D means

Rodeo Joe and others are right in questioning whether you need the kind of precision you seem to be asking for, for your purposes.

 

His Q&D tonal adjustment can get you close enough for a starting point, and then you can play with adding 'filters' in a reasonably complex image manipulation program to get something that "looks' right to that mark 1 eyeball

 

They calibration target is in every image so I thought I would try to use it. If there were all photographed at the same time / conditions, I can apply the correction for one target to all. so it is not that difficult. This would eliminate the ambient effects so I can focus on color matching to high quality text books Images.

 

Also what is "Q&D"

Rodney, Thank you. I wrote haiku for all one hundred prints in the series, that I am trying to publish.

 

 

Is this data in this article sufficient or would your measured values be more accurate. What are you rates?

 

https://www.imaging.org/site/PDFS/Papers/2002/PICS-0-267/7122.pdf

 

Do I fine tune the need to manually create a calibration file or try to fine tune the RBG slider to match the image target vales to the reference values. or do I need to do a Curve fit and change gamma settings within photoshop?

Do you actually want or need exact reproductions of the prints as they now appear?

Thanks for the swatch link. I would like (not need) the colors to be adjusted to how they appear when they were created. Which is more difficult than how they appear when they were documented. Since they are wood block prints from the 1800's. I have a book that has these prints with beautiful colors. I will try your swatch out, as a rough guide to correct the source and camera. I have to give more thought to doing it by eye vs the numbers.

Rodney, Thank you. I wrote haiku for all one hundred prints in the series, that I am trying to publish.

 

 

After I correct for the camera and source, is it worth while trying to create a compensation matrix from manually selected points across the color space from a higher quality reference image to restore faded colors, etc.? Or is color restoration by eye the easiest approach?

I think this may be more difficult than you think.

 

I assume that what you have posted is a photo of color patches sitting next to a page of a book (or in any case, next to a print). Changing color balance using the color patches would take care of errors in capturing and displaying the image. (using the gray scale, I got a shift of +11 toward magenta and +1 toward yellow in Adobe Camera Raw.) However, if the paper itself has yellowed with age--which looks to be the case here--using the color patches won't address that problem.

 

I've been mulling over exactly this issue with some artwork that was done on paper that has deteriorated and yellowed quite badly. One could guess what white the margins should be and adjust accordingly, but that would distort the colors, which show the underlying medium to varying degrees. I haven't figure out how best to do this, but perhaps someone else here has more experience.

 

 

Yes I agree, I would like a good starting point by eliminating the camera/illumination effects. This will likely turn into a color restoration project. I have a book with excellent color version of these prints. So I will manually adjust them to match. I wish I had the bandwidth to play around with machine learning image processing.

That isn't a MacBeth ColorChecker but there should be published Lab values of this target and easier still, in an RGB Working Space, all gray patches should be equal RGB (neutral) or as close as you can get depending on the data (encoding) and where the WB is applied.

I think I have that target around the color museum somewhere and can measure the individual color patches and produce LAB.

 

 

Rodney, Thank you. I wrote haiku for all one hundred prints in the series, that I am trying to publish.

Attached is an image of an art print that has a color patch to left. Is it possible to do color correction with all of the color patches in Photoshop or another program?

 

The problem is the color values of the original color patches are unknown. I am under the impression that a color checker software with a known calibrated target is required eg. Xrite.

 

I figured the best I can do is set the white balance and white and dark levels. I have 100 of these files to adjust. I suspect the corrections may all be the same if they were photographed at the same time and lighting conditons..

 

I have a book that has high quality images of the same prints, so I can visually adjust each one by one.

 

I plan to publish these photos in a book.

 

The other idea I had is that I have access to a color corrected file of the same print different edition. I could write a program in Matlab to look at the color difference between the two prints and create a normalization file to match the colors of the two prints. The color corrected file version copyrighted so I can't use it directly. Getting the two files aligned and registered will take a lot of work and might required some machine learning algorithm to do it successfully. It might be best to do it my eye.

 

I need to measure a laser generated grid 0.25mm width (4lp/mm) at 5 meters w/ 75% Contrast. Does anyone think that I would not be able to resolve that with a canon 135mm f/2.0 L, or the 200mm f/ 2.8L II lens at f/2.8? The MTF for both at 10LP/mm, 1.0 /1.5meters is 90% across the full field.

Are there any compact lenses for a 4k camera that are 1/2-1in in diameter?

My iphone 6 has really saved me. I have had about 8 kidney surgeries over the past few years and have not been able lift my DLSRs and L series lenses for many years now even after numerous PT visits. I really enjoy the Moment 18 and 58mm lenses, the bokeh is nice for a phone. I have been doing alot of ICM color photography w/ the slow shutter ap of flowers, and merging with old photos of cemetery statues taken in IR in my 5DMkII IR converted camera. I am in the process of selling many of my lenses to survive after my hours were cut 50%. I am still lucky to have a job and healthcare, and a camera I can lift. Hopefully in a year I will be able to lift, work full time, and travel again and buy back a few lenses. but my iPhone will still be part of my creative workflow.

I decided to support a used book store by buying a used copy on Amazon. I have read many of his other books, they are all excellent. River at the Center of the World is one of my favorites.

Whenever I see a linear periodic structure like this in an optical system, I immediate think interference fringes. I suspect that it is caused by interference of refections of the out of focus rays between the filter and the lens elements. Try a higher quality filter with more coating layers that will have a lower value of %R.

 

Other people have been commenting on this being a good example extended to a more general comment that all filters have a negative impact on image quality. Which is not a valid. There are many ways in which filters can potentially impact and not impact image quality and it is highly dependent on the lens, filter design, illumination conditions and the observer.

Eigen engineering sells iPhones and Android phones that have the IR filter removed for IR photography, as well as a wide range of filters,

 

Near Infrared (NIR) and Fluorescence Imaging Smartphone Developer

 

info@eigenimaging.com

Ludmilla. thanks for you reply. IR stands for infrared. The part of the optical spectrum beyond red outside of what the human eye can see. Here is a more detailed explanation w/ examples of Infrared Photography. what-is-infrared-photography.

 

I found that my roommates galaxy phone is sensitive the the IR light from a remote control. I will try to put the red long pass filter in front to see if it will work.

I am looking to convert a smart phone to shoot infrared photos. I apologize of I have missed any previous postings on this topic. I was surprised not to find this topic come up when I did a search

 

Questions/Options

 

1. Do Samsung Galaxy phones have and IR Blocking Filter?

- I don't own one so I can't check with a remote control LED

- If not, then I should be able to mount an IR long pass filter in front of the lens

 

2. Iphone X clone

- Requires that I take it apart to remove the IR blocking filter mounted to the lens assy

 

3. iPhone 6 or above

Is the IR cut off filter deposited on the sensor itself, of on a window in front of the sensor that could be removed by a lab?

 

4. Other options I have not consider.

I decided not so pursue this.

ok, I was hoping it was snapped together. Ok, you must have a newer model, I have a connector. thanks.